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By Tim G. Eastman, DVM, DACVS, MPVM It is an exciting time to be a veterinarian who makes his/her living by diagnosing and treating lameness in horses. First of all, our ability to diagnose lameness has improved dramatically over the past decades, with the explosion of technology available. The digital revolution has improved our ability to manipulate images to better evaluate them and to share the information with colleagues for consultation. Equine veterinarians are getting better ultrasound equipment and are becoming more adept at its use. Digital X-Ray equipment is becoming more affordable and more portable. Advanced imaging modalities such as MRI, Nuclear Scintigraphy (“Nuke Scans”), and Cat Scans are increasingly available and being utilized with increasing frequency. The ability to record these images digitally has made consultation with colleagues so easy that getting multiple opinions from specialists across the country is commonplace. With this diagnostic equipment available, conditions that used to be chalked up to a “foot lameness” can now be specifically diagnosed and treatment plans custom tailored. There are several new therapeutic options that have become available over the last several years for arthritis, tendon and ligament injuries, as well as other sport related injuries. The purpose of this article is to provide readers with some background information on a variety of new treatments you might here discussed around the barn. Tildren Tildren® is a drug that has been available in Europe for many years to treat navicular disease and has recently become available in the United States to veterinarians who go through special licensure. It is similar to drugs used to treat osteoporosis in people. The activity of the cells that cause the destructive changes we see on X-rays with navicular disease is suppressed. Apparently the activity of these cells is very painful and by reducing their activity, many horses become much more comfortable. There are many different treatment protocols being utilized with Tildren but most involve placement of an iv catheter and administration of a large amount of the drug as an iv drip for about an hour. Generally in 2- 4 weeks the benefits are beginning to be realized and the effect lasts for approximately six months. Horses may remain sound longer by giving monthly boosters. In addition to navicular disease, many veterinarians use Tildren to treat horses with hock pain. Many lameness diagnosticians feel that Tildren has been the first major breakthrough in the treatment of navicular disease in horses. IRAP IRAP II™ is not a music group, it is a somewhat new treatment for arthritis in horses and in humans. A chemical that is largely responsible for the pain associated with arthritis is called Interleukin 1. IRAP decreases joint pain by interfering with the activity of Interleukin 1 and similar compounds. For the procedure, you obtain a large syringe of blood. The syringe you pull the blood into has hundreds of glass balls that have been exposed to a certain gas that favors the “IRAP” and helps amplify it. Once the blood is obtained, it is incubated overnight and then spun in a centrifuge to separate the serum from the other components. This serum is rich in IRAP and once passed through a filter, is injected directly into the desired joint. Extra serum is frozen for subsequent treatments. Typically, a series of 3 injections are performed 1 week apart to treat 1 affected joint. Coffin joints and stifles that don’t respond well to steroid injections seem to be the most popular condition to treat. Reactions are uncommon largely due to the fact that it is the patients own serum. Stem Cells Stem cells have been injected into injured ligaments for many years now and are becoming increasingly popular as a treatment for joint disease as well. The idea is that by providing a large population of cells at the site of injury that are not yet committed to becoming any one tissue, you encourage them to become what is needed for repair. There are different ways to obtain stem cells for use in horses. One is to take bone marrow from the horse and inject it directly into the damaged tissue straight or after some modification. Another is a commercially available product called “A-cell” in which the source of stem cells is fetal pig bladder. A-cell comes in an injectable form used for tendon injuries and as a sheet used for treatment of wounds (A-cell is currently off the market but reports say it will soon be back). We have been using a 3rd source for the past several years with very promising success, a company called Vet-Stem. The stem cells used are not of embryonic origin but come from the patient’s own adipose tissue. By using the patients own fat, rejection becomes almost a non-issue. Apparently fat is a storage reservoir for stem cells which is handy because it is readily accessible. The fat is typically harvested through a surgical incision made above and to the side of the base of the tail. This fat is stored in a special container and sent overnight to a lab in southern California where the stem cells are separated out, suspended in saline, and sent back to the veterinarian again by overnight mail. Ultrasound guidance is then used to inject the stem cells directly into a torn ligament or tendon. Alternatively, the stem cells may be directly injected into a badly damaged joint. Initial research with fat derived stem cells in horses has been encouraging. Clinically, the ultrasound scans of tendon or ligament injuries is amazingly improved 60 days after injection and we feel like more horses are going back to their previous level of work with less recurrences. Shock-Wave Therapy Shock-wave therapy has stood the test of time for treatment of many lameness conditions. By sending “shock-waves” through damaged tissue you may enhance the healing process by rejuvenating the inflammatory stage. It also has a short-term pain killing effect. This is of concern because for example with a suspensory ligament injury we perform shock-wave therapy with the hope of an improved end product with less chance of recurrence. The short-term pain killing effect may tempt horse owners to begin training prematurely once an improvement in lameness is noted. Shock-wave therapy is used for a myriad of conditions including but not limited to: bowed tendons, suspensory ligament desmitis, “splints”, non-healing wounds, navicular disease, and hock pain. In closing, Tildren, IRAP, Stem Cells, and shock-wave treatment are several newer therapies available for certain lameness conditions. They have not replaced joint injections and many of the other treatments historically used for the management of lameness, but have sure been a nice addition to the therapeutic options available. Of course, different veterinarians have had different experiences with these modalities and will all have different opinions on effectiveness and case selection. Contact your veterinarian if you think your horse may benefit from one of these therapies.

By Nora Grenager, VMD Published in Bay Area Equestrian Network December 2007 Introduction Colic. To some, it is a term that is unfortunately all together too familiar; to others, it is a word that causes fear with little understanding of what it is. While it is a situation we would all like to avoid, it is important to have a knowledge of what colic is, some of its causes, potential ways to minimize its occurrence, and how your veterinarian may deal with it. Causes Approximately 4 to 6% of horses in the United States will suffer from colic each year. This is a difficult statistic to interpret, because many mild episodes of colic likely go unnoticed. Of that percentage, only a very small amount require surgery. “Colic” is just a term that encompasses any abdominal pain – it is a clinical sign, not a specific disease. Horses have very extensive gastrointestinal tracts, and there are numerous possible causes of colic. There are many ways to categorize the causes of colic. One is to divide the causes into those that can be resolved by medical treatment alone versus those that require surgical intervention. Most horses with colic respond to medical treatment, and only a very small percentage have a cause that will not get better without surgery. A second useful way to categorize the causes of colic is based on whether the small intestine or large intestine is the source of the pain. This is beneficial because sometimes the veterinarian can differentiate between these two locations during the exam, and treatment and prognosis tend to depend on which part of the intestine is involved. A third way to categorize colic is based on whether it is a one-time occurrence or whether the horse has had multiple episodes of colic over time (i.e. it is a chronic situation). To list the specific causes of colic is beyond the scope of this article. Clinical Signs The clinical signs (a.k.a. “symptoms”) of colic vary from horse to horse, and can range from very mild to very severe. Some mild signs include a horse not being as interested in feed as normal, having decreased number of manure piles, or quietly laying down more than normal (or at an abnormal time, such as feeding time). A colicky horse may be looking at its side and showing evidence of having rolled (is covered in shavings). Moderate signs may include pawing, lifting the upper lip, looking at the flank, kicking at the belly, or stretching out. Severe signs can include repeated rolling or thrashing and sweating. Every horse is different, so knowing what behavior is normal for your horse is important so you can tell when something is amiss. Also, some horses are extremely stoic whereas others are very are more sensitive and quick to show signs of discomfort, which can make interpretation of signs tricky. It is therefore important to remember that the severity of colic signs you see may not always correlate very well with the severity of the underlying cause. What to Do While Waiting for the Vet If you are concerned that your horse is showing colic signs, you need to call your veterinarian immediately. If you are comfortable doing it, and the horse’s signs aren’t so severe as to prevent it, taking a heart rate and rectal temperature and evaluating the gums prior to calling your veterinarian may be helpful so you have more information for the phone call (ask your vet — (s)he may have a preference as to whether you do this or not). Next time your vet is out, have him or her show you how to take your horse’s heart rate and rectal temperature, and evaluate the gums. Normally a horse’s heart rate should be between 30 and 40 beats per minute. A normal rectal temperature is between 99°F and 101.5°F. The gums provide insight about how well hydrated the horse is and should be pink and moist. When you call your vet, (s)he may ask about the duration of colic signs, if the horse has colicked in the past, how uncomfortable the horse is, and if the horse is passing any manure. There are different opinions on whether to walk a horse while waiting for the vet to arrive. If the horse is rolling and extremely uncomfortable, walking may help keep it quiet. Walking may help alleviate some gas, which can be a cause of colic. A horse should not be forced to walk, and laying quietly is generally okay. Most veterinarians prefer that you do not administer any medications to a colicky horse unless they advise you to do so when you call. This is because a dose of Banamine or dipyrone (or whichever painkillers you have) can make evaluating the horse difficult for the vet. The horse may temporarily look better while the vet is there, only to become colicky again later; thus postponing necessary treatment by the vet and potentially making the situation worse. Situations in which the vet may advise you to administer medication are if it is going to be a long time prior to the vet seeing the horse, or if the horse is dangerously uncomfortable. What to Expect from the Vet Once the vet arrives, (s)he will likely examine the horse (take heart rate and respiratory rate, take the rectal temperature, evaluate the gums, and listen to the gastrointestinal sounds). If your horse is extremely uncomfortable, this exam may be brief and the vet will administer intravenous sedation/pain relief quickly. (S)he will then likely ask you a few more questions about duration of colic signs, any previous colic episodes, any recent changes in feed or management, or other medications recently given. The most common initial workup for a colicking horse is for the vet to perform includes abdominal palpation per rectum and passing a nasogastric tube. The horse will likely be sedated for these procedures. Abdominal palpation per rectum (a.k.a. “the rectal exam”) gives the vet information as to whether there is manure passing through, the appearance of that manure, and allows palpation of about the back third of the abdomen. Obviously horses are very large animals, and it is not possible to feel everything in the abdomen. However intestinal distention or impaction and some intestinal displacements can be palpated, so this is very informative. Sometimes this is not done if either the colic is very mild, or if the veterinarian does not feel safe doing the exam. There is obviously a degree of risk in standing directly behind a horse and performing a rectal exam, which is why at veterinary clinics this procedure is preferentially performed in the stocks. Passage of a nasogastric tube has two distinct purposes. First, horses cannot vomit, so if the stomach is very full due to an obstruction of the intestine, it can get very distended. This is not only extremely painful, but it is fatal if the stomach ruptures. The quantity and quality of the reflux is useful information; it can help differentiate between small intestinal and large intestinal causes of colic. A normal horse may have 1 to 2 liters of nasogastric reflux, versus a horse with a small intestinal obstruction can have upwards of 20 liters of reflux. Second, a nasogastric tube is an excellent way to administer fluids and electrolytes to help rehydrate the horse. Horses with colic generally have some degree of dehydration. Additionally, your vet may add either mineral oil or detergent or epsom salts to the fluid to help soften the bowel contents. If your horse becomes colicky again once the sedation and pain medications have worn off, or the initial colic is severe, your vet may recommend intravenous fluids and additional treatment. Depending on the horse’s condition, the vet’s preference, and the available facilities, this may be done at the farm or (s)he may advise taking your horse to a referral veterinary clinic. At the Clinic If your horse is referred to a veterinary clinic (or some vets may have resources to do some of this in the field), diagnostics such as abdominal ultrasound, abdominal radiographs, abdominocentesis (a.k.a., “the belly tap”), or gastroscopy may be performed. These are four different ways to evaluate different parts of the gastrointestinal tract and gather more information. While every attempt is made to determine the cause of colic, the horse’s level of pain is the single most important deciding factor as to whether surgery is necessary. If a horse is repeatedly uncomfortable in spite of adequate pain medication and hydration, the cause of the colic is very likely something that is not going to resolve without surgery. If surgery is indicated, the vet will discuss with you his or her thoughts on the possible causes, tell you about the surgical procedure, and talk about the costs. Possible Preventative Measures Colic can be frustrating because, in a lot of situations, a reason for the colic episode is not determined. Possible causes that often are discussed include weather change (so the horse is not drinking enough water), change in feed, poor dentition, and parasites. While it is probably not possible to prevent all episodes of colic, there are certainly some things owners can do to minimize the risk. Regular feeding schedules are very important for gastrointestinal health. If any feeding changes are to be made, they should be done slowly over a week or two. Horses were also designed to graze and therefore they are suited to more frequent smaller feedings when possible. It is important to make sure there is always access to fresh, clean water. Note how much water your horse drinks, and be cognizant of decreases if there is a weather change and try supplementing water in other ways at those times. For example, feeding a soupy mash or adding a few tablespoons of apple juice or Gatorade to the water to tempt the horse (obviously always have available both plain and flavored water). Horses living on sandy soil should be fed in feeders with rubber mats underneath to minimize the amount of sand they ingest. Additionally, horses in sandy areas should be on a preventive psyllium program to help clear them of sand they take in. Studies have shown that horses in California (in particular, Arabians) that eat alfalfa are more likely to have enteroliths (stones that form in the colon that can cause colic and have to be removed surgically). Therefore, while alfalfa is a great feed source, it may be recommended to not feed it for more than 50% of your horse’s diet. Routine deworming is important for many reasons, and can help decrease the incidence of some types of colic. Routine dental care is critical, not only in older horses, because poor dentition can increase risk of impaction colics. Conclusion Certainly there are numerous causes of colic, but some of these can be avoided with routine good horse care and by being well-informed. Being armed with a little more information about colic can hopefully help to decrease the preventable risks and make a colic event less scary.

By Timothy G. Eastman, DVM, DACVS, MPVM Published in Bay Area Equestrian Network December 2006 The word “colic” comes from the Greeks and means “abdominal pain”. Horses are notorious for colic and are predisposed to it when compared to other species. Signs of colic include but are not limited to: being “off feed,” depressed, looking/biting at the flanks, stretching as if to urinate, kicking at the abdomen, and rolling in pain. Most long-time horse owners have experienced at least a mild case of colic in their barns. Generally, a couple of injections and some laxatives will take care of most cases. If not, a repeat visit is required for further more aggressive treatment. There are many factors that predispose horses to colic. Equine species have simple stomachs unlike most other grazing animals and are unable to vomit. They evolved grazing over most of their day but are now fed several large meals at once, morning and night. Horses also experience much more stress than their mustang counterparts with their busy show and travel schedules. Most often horses with colic have an over accumulation of gas in their intestines (“gas colic”) or a mild impaction. The cause is oftentimes undetermined but can be triggered by a change in feed, dental abnormalities, environmental stress (“change in the weather”), or transportation to name a few. Certain regions have forms of colic unique to their area, for example enteroliths/intestinal stones in California, or “ileal” impactions in the South (the ileum is the last segment of the small intestine and prone to impactions in areas that feed coastal Bermuda grass hays). In over 95% of the cases of colic that equine veterinarians treat in the field, horses respond to medical management. Flunaximine (Banamine®) is often given because it controls pain, reduces fevers, decreases inflammation, and binds toxins sometimes released by bacteria. Dipyrone is a drug given to reduce spasms of the GI tract and to reduce fevers. Buscopan ® is a new drug to the USA but has been used over seas for many years and has become very popular for treating colic. It is a potent, short-acting drug that reduces spasms of the intestinal tract. It also facilitates rectal examination because it relaxes horse’s rectums. Horses with colic are frequently sedated because the tranquilizers we use are among the most potent pain killers available and begin to work very rapidly. Tranquilization also makes passing a stomach tube and performing a rectal exam easier, safer, and less stressful for the patient. Stomach tubes are passed up the nostril, down the esophagus and into the stomach to relieve gas pressure from the stomach, and to empty the stomach of feed and water that are not passing through in a normal time frame. A “twitch” is oftentimes placed in order to making the tubing process less stressful and reduce the chances of a bloody nose. While sometimes dramatic to witness the event, passing a stomach tube may be considered an important part of the management of a particular case of colic. Once the tube is passed and gas relieved, medication may be pumped down the tube. Mineral oil is very popular to use as a laxative. Other veterinarians prefer a detergent (“DSS”) to soften horses up and help eliminate gas. Epsom salts are sometimes given to soften up impactions. What drugs are given and by what route are the preference of the treating veterinarian and may vary greatly depending on the situation. Rectal exams can help determine the severity of a colic case. Some impactions may be felt, the portion of intestine involved can be determined, and the amount of gas in the intestine can often be evaluated. Performing a rectal examination is not without risks and whether or not it is indicated depends on the circumstances of the colic. Horses with colic pain are under stress and this stress can lead to fluids being shifted from their blood into their intestines. This is frequently why they become dehydrated and need fluids to prevent the colic from progressing and to help them get their intestines working in a normal fashion again. They also support the patient until the colic has passed. Fluids can be given via a stomach tube or by an IV catheter. Intravenous fluids are one of the most important therapies for more horses with more serious colic. Some combination of the above therapy will bring >95% of horses with abdominal pain through it just fine. However, sometimes the cause of the colic is such that fluids and medical therapy will not resolve the source. There are many causes of this more serious form of colic. The most common ones seen in Central California involving the large intestine are displacements, torsions (“twists”), and feed or enterolith impactions. Colics involving the small intestine in our area are typically more serious and may be from a fatty tumor that wraps around the intestine, or the small intestine being trapped and it’s blood supply cut off. These are the cases that often need surgery to physically relieve the obstruction or to mechanically replace the intestine back in its proper alignment. If a segment of the intestine has lost its blood supply for more than several hours, the affected portion may need to be removed and the healthy ends attached, or a bypass performed. Colic surgery is needed in these 5% or so of overall colic cases to give the best chance of success. The first obstacle to overcome with a horse during colic surgery is the ability to correct the problem. There are some instances when the exploratory reveals a hopeless situation. However, more than 80% of horses with successful colic surgeries will make it home. This is a substantial improvement over the past several decades and due to advances in anesthesia, surgical techniques, and aftercare. Abdominal pain caused from the small intestine tend to be more serious than ones caused by the large intestine and are typically more expensive to manage due to the drugs they require during surgery and aftercare. The vast majority of horses discharged from colic surgery will lead totally normal lives several months later. When trouble happens following colic surgery it can be from the inability of the intestine to regain normal function (“ileus” is the name for this), diarrhea, laminitis, and infections of the incision, etc. Huge advances have also been made in recent years with the management of these complications. Not everyone considers colic surgery a viable option for their horses due to previous experience, cost, or patient’s age etc. I think it is a good idea to make that determination periodically because the decision can often be hard to make in the middle of the night under stress. Medical insurance is actually very affordable and should be emphasized for family “pet” horses as much as in expensive performance horses. Care Credit® ((1-866-893-7864) is a company that offers a very reasonable payment plan for pet owners through many veterinarians. The age of patients undergoing colic surgery is less of a concern due to the same advances listed above. Many horses in their late twenties still undergo colic surgery on a regular basis. As a horse approaches his/her twilight years, when to draw the line with regards to whether or not a patient would get surgery for colic is an individual decision. Part of the job of your veterinarian is to assist you with guiding you through that decision process. In closing, most horses with colic will respond to simple medical management at the farm, if they do not, transportation to a hospital may be needed for further evaluation or treatment. Colic surgery has made huge advances over the past several decades for those rare cases that do not respond to simple medical therapy.

By Alexandra Eastman, DVM, MS Published in Bay Area Equestrian Network November 2007 It’s never too soon to start thinking about next year. Planning ahead can make breeding your mare less stressful and more fruitful. Many broodmare owners can run through breeding programs in their sleep, but for those new at the game, the following may be helpful in demystifying the process of breeding your mare. More than Two Months Before Breeding Discuss with your veterinarian the pros and cons of breeding your mare. There are many things to consider. How is your mare’s general health? Healthy mares that are not over or underweight tend to be most fertile. How old is your mare? Does she have any congenital problems that you would not want to pass on? Because of love they feel for their mare, many people overlook the consequences of breeding mares with undesirable heritable traits. Is she reproductively sound? A breeding soundness exam can help evaluate the reproductive health of your mare. If done early, it can help by identifying problems that may need treatment before you are trying to breed. During this time you may also want to research prospective stallions. You will want to establish a breeding contract ahead of time with the stallion owner. This is a time for you to familiarize yourself with the details of the contract. You may want to ask about the pregnancy rates of the stallion, the fees you will incur during the process, the collection days, and breeding season. Which stallion you choose may effect how your mare will be bred. Mares are bred by natural cover or by artificial insemination (AI). If your mare is to be bred by natural cover, you will probably transport your mare to the stallion for breeding. If she is to be bred by AI and the stallion ships well, it is possible for her to be bred with transported semen. Transported semen comes in one of two forms: cooled or frozen. There are advantages and disadvantages to each method. Pregnancy rates are highest in mares bred by live cover or artificially inseminated immediately after collection. However, transporting the mare to the stallion may not be practical or desirable. In most cases cooled semen has higher pregnancy rates than frozen semen but cooled semen must be ordered and shipped for each breeding. Depending on the collection schedule and shipping methods offered by the stallion owner, this can be difficult to orchestrate with the actual ovulation of the mare. Frozen semen is nice because it sits in the tank waiting for the mare but the conception rates are lower and the timing must be more precise so the mares need to be checked more frequently by a veterinarian. Breed registries have differing rules regarding AI and transported semen. If you intend to register your foal, you should check the rules of your specific breed association. Two Months Before Breeding Mares are seasonal breeders. They cycle, produce and release ova from follicles, during the months with the longest day length. During the winter they enter a period of diestrus and stop cycling. As mares begin to cycle in the early spring, they enter a period of transition. During this time the mares may show signs of being in heat but their cycles tend to be unpredictable making it difficult to achieve good pregnancy rates during this time. Without any intervention the ideal time to breed mares in the northern hemisphere is May through August. During this stretch of time, the mares are usually cycling consistently and are most fertile. The length of gestation is extremely variable but pregnancy usually lasts about 340 days. For many breeds the foals have an automatic birthday of January 1 st. Foals destined for age group competitions will have an advantage if they have an actual birth date early in the year. For owners hoping for birthdays early in the calendar year, May through August is usually considered too late to be acceptable breeding dates. The simplest and most effective method to get a mare to cycle earlier in the year, is to increase her “day length” 60 days before you want her to start cycling. For most mares this means adding light to their stall starting on December 1st. The most common method is to add light at the end of the day before dusk making the mare’s day length 15-16 hours/ day. This can be most easily achieved by placing the lights on timers to light the stall from around 4:30 pm to 10-11pm each day. Leaving the lights on all night or skipping days will negate the effect. The lights do not have to be overly bright. The rule of thumb is that you should be able to comfortably read a newspaper. One Month Before Breeding If possible, start teasing your mare to determine her heat cycle. Mares that are in estrus (heat) usually stand calmly, squat and wink the labia of the vulva in the presence of a stallion. They often raise their tail and urinate. Mares that are not in estrus tend to be more agitated in the presence of a stallion. They are restless and may lay their ears back, squeal and kick. Some mares will tease to geldings or other mares when they are in heat. Other mares will not overtly show signs of estrus even when teased with a stallion. Many mares with foals are so protective of the foals that they won’t show estrus behavior. Teasing is not always possible. Your veterinarian can determine the stage of estrus by examination of the ovaries, uterus and cervix of the mare. If your mare is to be bred with transported semen, contact your veterinarian to determine when they would like to start following your mare’s cycle. If your mare is going to travel to the stallion farm, contact the breeding manager or stallion owner to determine when they would like you to bring your mare. If your mare is to travel out of state, be sure to check with your veterinarian about the timing and requirements for an interstate health certificate and Coggins testing for the state in question. Desired Breeding Time Arrange for breeding either by your veterinarian or the stallion manager. The attending veterinarian will probably want to check your mare after breeding to ensure that she has ovulated and that she did not acquire any post breeding fluid within her uterus. Even with the use of drugs to induce ovulation, some mares do not ovulate when expected. If this is noted on a post-breeding exam, there may be a chance to order more semen. Many mares, especially older mares, will have difficulty clearing fluid from their uterus after breeding. If this happens, it can provide an inhospitable environment for the embryo and the pregnancy will be lost prior to implantation. Oxytocin with or without uterine lavage can greatly increase the chances of a viable pregnancy Pregnancy Exams Pregnancy can usually be diagnosed by ultrasound 14 days after ovulation. A fetal heartbeat can usually be detected ultrasonographically at day 24 or beyond. At the heartbeat check be sure to discuss with your veterinarian protocols for vaccination (most veterinarians recommend EHV-4 vaccination at 5, 7, and 9 months of gestation as well as core vaccinations 1 month prior to foaling). Specific recommendations may vary between veterinarians or by region. It is very nice when everything goes as planned. You find a stallion, your mare comes into heat, she is bred in a timely fashion and she takes the first time. This does happen sometimes. However, like it or not, mares are individuals and they don’t always come into heat when you expect them to, ovulate when they should, or they have trouble with post breeding fluid. Sometimes the semen misses the connecting flight or the stallion is collected Monday, Wednesday and Friday and they only ship FedEx and you really need the semen on Monday and you are out of luck. Generally the most effective tool in a successful breeding season is good communication. If you have all of your questions answered ahead of time by your veterinarian and by the stallion manager and you are kept up to date as the process unfolds you shouldn’t have too many surprises.

About EHV-1 Equine herpesviruses (EHV) are found in the majority of horses. Most horses have been exposed to the virus and have had no clinical signs or side effects. There are nine EHVs that we have been able to identify worldwide, but EHV 1, 3, and 4 are the strains that have caused clinical disease in horses. EHV-1 specifically has multiple manifestations of disease in horses: neurological form, respiratory form, and can cause abortion and neonatal death. There is also some evidence that it may cause chorioretinopathy (a disease process in the eye). Research has shown that greater than 80% of horses may be latently infected with the EHV-1 virus, but not all horses will develop clinical signs. The Science Behind EHM EHV-1 myeloencephalopathy (EHM) is still being studied today and we are constantly acquiring new information. There are multiple reports of theories describing how the virus causes neurological disease. A single point mutation in the DNA polymerase gene has been associated with neurological disease, causing the presence of aspartic acid (D) or asparagine (N) at position 752. AAEP reports that 80-90% of neurological disease cases are caused by D752 isolates, and 10-20% by N752 isolates. Recently, there has also been a proven association with a single nucleotide polymorphism at position 2254 in the DNA polymerase gene and the occurrence of EHM. The virus can become reactivated and furthers cell-associated viremia delivering the virus to endothelial cells in the uterus and central nervous system. Clinical signs occur due to the vasculitis and cellular damage caused by the virus. Infection of Horses Horses are affected through contact with respiratory secretion, aborted fetuses/placentas, or by fomites (infected objects, such as grooming tack). Following infection, a viremia is established as the virus circulates the body in infected cells. Following this, virus-infected cells are latently infected. Horses can shed virus in nasal secretions as early as day 1 of infection, and can continue to shed the virus for approximately 28 days. The virus can cause disease in infected horses or can re-activate from latency causing clinical disease in the horse. The virus can typically survive in the environment for up to 7 days, but this can vary based on the environmental conditions. Signs of EHM The incubation period of EHV is typically 4-6 days, but has the potential to be longer. Some clinical signs associated with the neurological disease may include: Fever Nasal discharge Hindlimb weakness Incoordination Loss of tail tone Lethargy Urine dribbling Head tilt Inability to rise Diagnosing EHM Clinical signs (neurological signs and fever) and isolation of the virus are how we confirm EHM. Isolation of the virus can be done using quantitative polymerase chain reaction (qPCR) from nasal swabs and blood collection. Treating and Preventing EHM After confirming EHM, implementing a strict quarantine and biosecurity measures under supervision of local and state veterinarians is key. Treatment options include anti-inflammatories and supportive care. Vaccination and biosecurity protection are the two ways to help avoid disease outbreak. No current EHV-1 vaccine has a claim to prevent EHM. Some EHV-1 vaccines can reduce nasal shedding and possibly viremia. By vaccinating your horses, you induce a strong immune response to the virus without inducing clinical disease. It is important to clean tack, equipment and the environment to inactivate the virus. Cleaning first with a detergent or soap to allow for removal of organic material (such as soil) is recommended in order to prevent disinfectants becoming inactive when they make contact with organic material. There are multiple effective disinfectants that will kill the virus, including 1:10 dilution of bleach to water. Other key points for understanding EHM prevention include: Immunity following infection or vaccination offers limited protection Boosting (routine vaccination) contributes to herd immunity to help protect individual horses It is difficult for the body to establish immunity due to “evasion” properties of this virus Early recognition and diagnosis is key Quarantine and close monitoring of suspected cases is important Exposed horses should have their temperature taken twice daily Please note that this virus is still being investigated and new research is constantly being release as we try to better understand EHM. Additional resources: AAEP: Equine Herpesvirus Resources California Department of Food and Agriculture: Equine Herpes Virus References: Allen GP. Risk factors for development of neurologic disease after experimental exposure to equine herpesvirus-1 in horses. American Journal of Veterinary Research 69,         1595–600, 2008 Diallo IS, Hewitson G, Wright L, Rodwell BJ, Corney BG. Detection of equine herpesvirus type 1 using a real-time polymerase chain reaction. Journal of Virological Methods          131, 92–8, 2006 Diallo IS, Hewitson G, Wright LL, Kelly MA, Rodwell BJ, Corney BG.            Multiplex real-time PCR for the detection and differentiation of equid herpes- virus 1 (EHV-1)          and equid herpesvirus 4 (EHV-4). Veterinary Microbiology 123, 93–103, 2007 Dunowska M. A review of equid herpesvirus 1 for the veterinary practitioner. Part A: Clinical presentation, diagnosis and treatment. New Zealand Veterinary Journal, 62,         171–78, 2014a Dunowska M. A review of equid herpesvirus 1 for the veterinary practitioner. Part B: Pathogenesis and epidemiology. New Zealand Veterinary Journal, 62, 179– 88, 2014b Equine Herpesvirus (Rhinopneumonitis). (n.d.) Retrieved March 7 2016, from http://www.aaep.org/-i-173.html Goodman LB, Loregian A, Perkins GA, Nugent J, Buckles EL, Mercorelli B, Kydd JH, Palu G, Smith KC, Osterrieder N, Davis-Poynter N. A point mutation in a herpesvirus      polymerase determines neuropathogenicity. PLoS Pathogens 3, e160, 2007 Pusterla, N., & Hussey, G. (2014). Equine Herpesvirus 1 Myeloencephalopathy. Veterinary Clinics of North America: Equine Practice, 30(3), 489-506.

By Timothy G. Eastman, DVM, DACVS, MPVM Published in Bay Area Equestrian Network March 2008 The pastern joint, also known as the proximal interphalangeal joint, is a relatively common source of lameness in horses (Figure 1: Note the smooth borders of the bones along the front of the pastern joint of this normal horse). Degenerative joint disease/arthritis of this joint is commonly referred to as high ringbone. Low ringbone refers to the same type of degenerative joint disease of the coffin joint and is much less common. Horses afflicted with high ringbone are difficult to keep sound. The area is similar to the lower hock joints in that it is a “high-load/low motion” joint, meaning the joint is subjected to a lot of pressure but undergoes very little movement. Unlike the lower hock joints, the pastern joint does not respond consistently to intra-articular injections. The diagnosis of high ringbone is based on localizing the source of the lameness to the pastern joint with nerve and/or joint blocks. Lameness can be classified as minor and only apparent with extreme exercise or severe enough to cause lameness at a walk. Radiographs and ultrasound are useful in confirming the diagnosis and determining the severity of the disease. Radiographically you see new bony growth along the front and the sides of the joint (Figure 2: Compare the new bony growth along the front of this arthritic pastern joint to the normal one in Figure 1). These bony prominences can sometimes be seen and felt prior to radiographs during the physical examination. If the disease was traumatic in origin, ultrasound can be particularly useful in identifying any concurrent soft-tissue injuries complicating the prognosis. A complete series of radiographs is necessary to determine the severity of the disease as the sides of the joint can only be seen on oblique views. Quarter Horses are predisposed to ringbone due to the rotational forces they exert on their lower limbs during the sudden stopping and turning common in Western Performance. Treatment of ringbone can be divided into medical and surgical options. Medical management of ringbone is aimed at slowing down the progression of cartilage degeneration and reducing pain and inflammation associated with the condition. Helping to “ease the breakover” of the foot will decrease the forces subjected to the front of the joint and can be accomplished by a farrier “squaring” the toe and “rolling” the shoe. Like any lameness condition, there are many ways to shoe for the same problem. Anti-inflammatories like Phenylbutazone (“bute”) are used to decrease inflammation associated with acute flare-ups of the condition and to manage horses on a long-term basis. Many horses with ringbone can be sound enough for light use by giving bute before and after exercise. Oral joint supplements alone are unlikely to be sufficient to provide relief but are thought by some to slow down the progression of the disease. More aggressive joint supplementation would include Legend? and/or Adequan?. Legend is an intravenous form of hyaluronic acid which is important in lubrication of joints and is an essential component of joint fluid. Some horses with ringbone will be sound enough for athletic use with Legend therapy alone. Adequan is an intra-muscular injection and is thought to delay the progression of cartilage degeneration. Injecting the pastern joint is not rewarding as consistently as some other joints but should be attempted to evaluate an individual horse’s response. There is tremendous variability with regards to how long an individual horse will respond to pastern joint injections. If controlling the disease with anti-inflammatories, shoeing changes and joint therapy is not sufficient to allow pain free performance, surgically fusing the joint may be the only option to provide pain free performance. While this procedure involves a major surgery, it offers the possibility of complete return to work and relief from pain for many horses. Research has shown that 2 out of 3 horses with ringbone of the forelimbs and greater than 4 out of 5 horses with hindlimbs affected will be sound enough for athletic use with surgical fusion. This joint is fused with a combination of plates and screws (Figure 3). Typically horses are maintained in a cast for several weeks, then a bandage and stall rest for several months prior to returning to full work. As with any lameness condition, your veterinarian and farrier need to work together to provide your horse with the highest level of soundness possible and to help you determine the best course of action for your particular horse.

By Timothy G. Eastman, DVM, DACVS, MPVM Published in Bay Area Equestrian Network March 2006 Enteroliths are one of the leading causes of severe colic in the state of California. The word enterolith is derived from the Greek terms “entero” meaning intestinal and “lith” meaning stone (Figure 1). The high incidence of enterolith formation in California is presumably due to the mineral content of our hay and water. Commonly referred to as stones, enteroliths are composed of struvite crystals that coalesce around some central object like a pebble or a small piece of wire ingested by the horse. When you cut an enterolith in half, you can frequently visualize a central body with rings of mineral deposits around it resembling rings in a tree trunk. The stones can be small and passed unnoticed in the manure or large enough to cause life threatening obstructions. The largest one I have seen was the size of a basketball. When they are round in shape, it usually means they are the only enterolith present, when several stones are adjacent to each other, they often become pyramid shaped by rubbing against each other. Enteroliths are a very important cause of colic in California and several other states. All the precursors of the struvite crystals (magnesium, ammonium and phosphate) are readily abundant in our water as well as our hay. It is widely recommended to limit alfalfa hay to 50% or less of a horse’s roughage because horses fed predominantly alfalfa hay are statistically more likely to develop stones than other horses. While enteroliths have been found in most breeds of horses, there is a breed predilection for Arabians and Morgans. The classic presentation for a horse with an enterolith in many practices would be a 10 year old Arabian horse fed predominantly alfalfa hay with a history of multiple colic episodes. Enteroliths take approximately 2 years to form a sufficient size to cause an obstruction. Therefore, horses with small enteroliths may or may not exhibit colic signs In many cases, there is a high index of suspicion based on breed and diet history. Because the stones can move within the large intestine, they can cause an obstruction with resultant build up of feed and gas causing pain, and then roll back out of the way allowing gas and feed to pass. When this happens, horses can have several episodes of mild to moderate colic over a relatively short period of time. In horses with suspected enterolithiasis, abdominal radiographs (x-rays) are the most likely route to a diagnosis. In a horse held off feed for 12-24 hours, enteroliths will be identified on abdominal radiographs greater than 80% of the time. Enteroliths too large to pass in the manure must be removed surgically. Almost every year, the most common cause of emergency abdominal surgery in California is stone removal. Counter-intuitively, the worst form of the disease is not the largest stones. A baseball sized stone that has passed from the large colon into the small colon causes more problems than their larger counterparts which are too large to leave the large colon. Baseball sized enteroliths can cause 100% obstruction and severe pain. If left untreated, the small colon can rupture causing peritonitis and resulting in death of the horse. Generally colic surgery for the removal of an enterolith has a very good prognosis. Greater than 90% of horses undergoing colic surgery for enterolith removal will survive and go back into full work. However, enteroliths that have moved into the small colon have a somewhat worse prognosis for surgical correction than their large colon counterparts. Unlike the small colon, almost the entire large colon can be exteriorized (lifted out of the abdomen) during surgery, allowing stone removal to be accomplished in an isolated area. This minimizes the chance of contamination of the abdomen with intestinal contents. Prevention of stone formation can be best accomplished by limiting the amount of alfalfa to less than 50% of the diet, housing horses in an area not known for stone formation, and attempting to acidify the diet. One cup of Apple Cider vinegar fed twice daily is commonly used in an effort to lower the pH of the large intestine to decrease the likelihood of stone formation. Additionally, a product called Restore® claims to be effective at reducing enterolith formation and possibly even an alternative to “dissolving” enteroliths in horses with stones not requiring immediate surgery.

By Timothy G. Eastman, DVM, DACVS, MPVM Published in Bay Area Equestrian Network August 2007 After Kentucky Derby winner Barbaro underwent surgical repair of a severe fracture many equine veterinarians were hearing the same statement “I didn’t think you could fix a broken leg in a horse.” The truth is some you can and some you cannot. This article will describe recent advances in fracture fixation in horses and attempt to clarify why some fractures are considered “good” fractures and some are considered “bad.” The first sign of a fracture is generally a non-weight bearing lameness. The first thing to rule out is the most common cause of severe lameness in horses, the foot abscess. With foot abscesses the foot is frequently warm and the pulse to the foot is increased. Start at the hoof and work your way up the limb applying pressure every several inches around the limb to check for other sites of pain, heat or swelling. The horse should be confined and a veterinarian called immediately to help differentiate the two. Sometimes with fracture of major long bones the diagnosis is unfortunately very easy due to instability of the leg. With some fractures the goal will be returning a horse to full athletic soundness. In other instances you are attempting to save their life for “pasture” soundness. Which ones are good and which ones are bad can be very surprising and should be evaluated by someone specializing in fracture repair. The cost associated for repair of many fractures can vary tremendously depending on the duration of hospitalization, number of implants (plates and screws etc.), type of surgery needed etc (See Figure 1: Radiograph showing use of large number of implants). The biggest challenge facing equine surgeons with regards to fracture repair is the fact that horses for the most part need to remain weight bearing on all 4 limbs. This is true even in the case of a fracture. If a person has a serious fracture of a limb, we are generally confined to bed rest for long periods of time and then transitioned to a wheel chair or crutches and possible a walking cast if all goes well. Horses need to be able to put weight on a fractured limb immediately after surgery. Add in the fact that many of our equine patients weigh well over 1,000 pounds and are “fight or flight” animals and the challenges become obvious. Most fractures even in large horses could be repaired but the opposite (“good”) leg needs to be able to bear weight. If the good leg supports too much of the horses body weight for too long a period of time, the support structures of that leg start to break down frequently leading to laminitis. This is why it is better to have a fracture of the hind limb than of the forelimb. Forelimbs must also support the weight of the head and neck. Laminitis of the “good” leg is called “support limb” laminitis and represents one of the most serious forms of the disease (this is what ultimately led to the demise of Barbaro). Body weight is the primary reason that fractures in foals and ponies tend to carry a much more favorable prognosis than full sized horses. In general, most fractures in foals less than approximately 500-600 pounds are candidates for repair (see Figure 2: Radiographs showing cannon bone fracture in foal and repair). As body weight increases, the biggest determining factor for prognosis becomes the bone involved. In general, full sized horses with a fracture below the knee or hock may be candidates for surgical repair. Fractures above the knee or hock in full sized horses carry a poor prognosis unless the bones are not displaced at all. X-rays are generally needed to provide an accurate prognosis. Other factors include where in the bone the fracture occurred (i.e. how close to the middle), whether or not the fracture extends into a joint, the number of pieces involved, and whether or not the skin over the fracture is intact (a “closed” fracture) or has penetrated the skin (an “open” fracture). The first-aid applied can be of paramount importance in improving chances for survival. Equine veterinarians are trained in how to best prepare a horse with a fractured limb for transportation to a surgical facility. Improper first-aid can lead to a closed fracture becoming an open one. In general, open fractures have a much lower prognosis and a much higher cost associated with treatment. The reason for this is the next big challenge in fracture repair, infection of the implants can be a very serious complication and repair of open fractures have a higher incidence of infection. As bacteria gain access to the stainless steel implants they may secrete a “biofilm” that can prevent the access of antibiotics and lead to loosening of the screws and plates used in a repair. Antibiotics given intravenously or intramuscularly often are not sufficient to combat infected implants and a race may begin where the fractured bone hopefully heals before infected implants need to come out. Some of the biggest recent advances in fracture repair in horses have been in the treatment and prevention of infections. There are very few implants used in fracture repair in horses that are designed specifically for horses, most are made for people. Although it seems intuitive that horses would just need much bigger plates, the laws of physics and the amount of skin present limit the size of the plates that may be used. Plates used in fracture repair are designed to compress the fractured bone ends together. Plates and screws are oftentimes not sufficient to allow a horse to bear weight after surgery so some type of cast is frequently needed. A “transfixation cast” is sometimes placed due to the fact that this type of cast can support the majority of the weight of the limb (see Figure 3: Transfixation cast). With transfixation casts, large pins are placed through the bone above the fractured bone and then incorporated into the cast. This transfers the weight of the limb through the pins to the cast. These casts are not without risk as additional fractures can occur through the holes used to place the pins. However, the added protection of a transfixation cast can sometimes be the difference between success and failure. One of the most stressful times in repair of a fracture is getting the horse from the operating table to back on their feet. Options to help minimize the chances of the repair falling apart include pool recovery systems like used on Barbaro at New Bolton Center, recovering in a sling, or using a system of ropes on the head and tail to assist in standing (see Figure 4: Horse recovering from anesthesia in a sling). In closing, surgical repair of fractures in horses will always remain a huge challenge for equine surgeons due to the above mentioned factors. However, many fractures that were once hopeless are now fixable. If you suspect your horse has a fracture work with your veterinarian to decide whether or not surgical repair should be attempted. Even though fracture repair has made huge advances in recent years, it can still be a major undertaking and the risks and benefits should be thoroughly weighed before choosing repair.

By Timothy G. Eastman, DVM, DACVS, MPVM Published in Bay Area Equestrian Network October 2006 Horses are “fight or flight” animals and have a great propensity towards skin wounds which generally occur while avoiding a potential threat, are surprised, or by accident. Oftentimes horse owners are faced with the dilemma of examining a wound and determining whether or not a veterinarian needs to be contacted. The aim of this article is to clarify some differences between wound types with regards to severity and prognosis, as well as provide an overview of current concepts in wound management. Abrasions are wounds involving only the superficial layers of the skin. As they are generally not all the way through the skin, they can not be sutured. They may however be very painful and can cause a great degree of lameness. If severe, they should be closely evaluated to make certain that no portion of the abrasion goes full thickness into an important structure. Generally they respond well to hydrotherapy, sweat-wraps and anti-inflammatories (“bute”). Horses do get bruises or contusions, they are just more difficult to see than in humans because of their thick hair coat. These are treated according to severity. Puncture wounds typically create a lot of necrosis of deep muscle tissue and are generally treated by daily lavage (“flushing”) and antibiotics. Because of the degree of deeper trauma, oftentimes these are not closed primarily but are allowed to heal by second intention. One common puncture wound is nail punctures to the feet. Where the nail goes is of paramount importance and can be very difficult to determine once the nail is removed. For this reason, most veterinarians recommend leaving the nail in place until an x-ray can be taken to determine what structures are involved (see Figure 1: Radiograph (x-ray) showing a nail puncture to the foot that missed all vital structures). Most don’t involve vital tissues and are managed similarly to foot abscesses. Those that involve vital structures (primarily the navicular bursa) are very important and managed aggressively like infected joints discussed later in this article. The most common type of wound in horses is a laceration (“cut”) of the face or limbs. Most lacerations can be sutured if caught early enough and should be evaluated by a veterinarian. Most wounds if sutured will heal in 2 weeks with minimal scar formation. As in people, laceration repairs in horses sometimes fail. If this occurs contact the veterinarian who performed the repair as he or she may want to re-evaluate the wound and change game plans. When a laceration is Radiograph showing a nail puncture to the foot that missed all vital structures. sutured closed, it is said to heal by 1st intention or “direct” healing. A laceration allowed to heal on its own by heals by 2nd intention or “indirect” healing. Sometimes veterinarians allow a wound to be treated under a sweat wrap for 1 or more days prior to closure, this is “delayed primary closure”. Delayed primary closure is sometimes used when a laceration has passed the “golden period” which is the time (approximately 6 hours for the average wound) in which a wound is likely to be managed by suturing because contamination and/or infection has not become established. The BIG thing is that if the wound is over a synovial structure (a joint, tendon sheath or a bursa) it needs to be treated immediately as wounds involving these structures can be life threatening. Tendon sheaths occur in front of and behind most joints of the limbs of horses. They serve to provide fluid identical to joint fluid to lubricate tendons as they glide over bony prominences. A bursa is a synovial fluid filled sac which, like a tendon sheath, serves to facilitate tendons gliding over bony prominences. The navicular bursa is often treated in navicular disease, distension of the olecranon bursa is a “shoe boil”, and distension of the calcaneal bursa is a “capped hock”. It can be difficult to determine if a wound involves a synovial structure (joint, tendon sheath or bursa) but a good rule of thumb is if a wound is within a hands breadth of the middle of a joint, involvement of a synovial structure is more likely. More on this later. So, if you identify a laceration on a horse under your care, the following steps should be taken. First evaluate the degree of bleeding or hemorrhage. If you can “count the drops” as the wound bleeds, you have plenty of time to treat the wound. If however, there is a steady stream of blood shooting from the wound under pressure in veterinary school they preach “Don’t Panic, Apply Direct Pressure, Clamp, & Ligate”. The first two things, don’t panic and apply direct pressure should be performed by the caretaker. Direct pressure will decrease most hemorrhage to a safe level. This can be accomplished with a towel, gauze or even just a hand until a bandage can be applied. Bandage material should be a part of everyone’s first aid kit at the barn and in the trailer. A bandage of just good thick cotton material and “vet-wrap” is generally sufficient to maintain pressure on a lacerated vessel until a veterinarian arrives. If hemorrhage is minimal or it has been controlled the wound should be thoroughly cleaned. Betadyne or Nolvasan are the two anti-septics used most commonly in horses and both are very effective. Cold hosing a wound is a good first line of defense followed by thorough scrubbing with an anti-septic. Once the wound has been cleaned, it is generally safe to apply an antibiotic ointment (Furacin, Nolvasan, Silvadene etc) and a light bandage if possible. This is now the time to contact a veterinarian. You have assessed the wound location and can provide a reasonable description of the wounds proximity to the nearest joint, as well as the thickness of the wound and applied first-aid. It will be the call of the veterinarian whether or not a visit is indicated. If you can pull the skin edges apart, it is a full thickness laceration and most veterinarians will recommend an evaluation unless it’s very small and in a safe spot. Virtually any equine veterinarian can tell you horror stories of very small wounds in a bad spot that were not properly managed and led to the horse’s ultimate demise so they don’t mind being consulted. The vast majority of wounds are superficial and do not involve any vital structures. In general, they will be managed by having the surrounding hair clipped and being thoroughly cleaned, the edges of the skin around the wound “blocked” with a numbing agent (lidocaine or carbocaine) and primary closure will be attempted. Wounds of the lower limb may not be blocked directly but be desensitized by having their nerve supply temporarily deadened. Some wounds because of their location or the nature of the patient require general anesthesia. Oftentimes, wound edges will be “freshened up” by trimming the margins. This makes a traumatic wound more like a surgical incision which tends to do better. Whether or not they will need to be covered by a bandage generally depends on veterinarian’s preference as well as location (most wounds of the lower limb are bandaged). The same is true about indication for antibiotics. All wounds and circumstances are different and some don’t mandate antibiotics at all while others require several weeks of intravenous antibiotics. Most are managed with oral antibiotics administered by the owner under the guidance of the veterinarian. The lower legs and face are probably the most common sites for lacerations. Wounds around the face have a very good blood supply and usually heal very well with primary closure. In many instances, the same wound on a leg would be allowed to heal on its own but on the face closure is attempted. Typically the sutures will be removed from any of these wounds in 12-14 days. Wounds involving the foot, especially the heel bulbs are under a lot of tension while horses walk which is why they are frequently managed by a “foot cast” (see Figure 2: A foot cast extending up to the mid-pastern area). This is a cast that you can generally manage at your barn as it does not extend up above the fetlock. Heel bulb lacerations tend to heal much better in these casts and you actually probably save considerable money in the long run as several bandages typically cost more than one cast. These casts are typically removed in 2-3 weeks. Another way to manage wounds that are under tension, especially those further up the limb is the use of “stents”. Stents are just devices that distribute the pressure of the suture over a wider area. This can be accomplished with plastic tubing placed between the suture and skin, buttons, and a whole host of other ways. Lacerations involving joints are a whole different thing. Once a wound communicates with a synovial structure, it is assumed that the structure is infected, and it does not take very many bacteria at all to do this. Septic arthritis is the result of an infected joint and due to the damage the bacteria cause to the cartilage and surrounding structures as well as the amount of pressure exerted on the joint capsule as fluid pressure rises, horses can be as lame as if they had a fracture. The resultant arthritis can be severe enough to cause permanent lameness. Also, the “good leg” opposite the wound now has to bear more than its fair share of the horse’s weight which can lead to laminitis. Whether or not a synovial structure is involved is the first thing your veterinarian will try to determine. If that assessment cannot be made visually, further precautions are necessary. If a wound is near a joint for example, the surrounding area is typically cleaned very thoroughly and a sterile needle will be placed into the joint away from the wound (see Figure 3: Sterile fluid being injected into a fetlock joint to determine if the wound communicates with the joint). The joint is then distended with sterile saline and the wound is closely inspected for fluid leakage. If fluid injected from a syringe away from the wound comes out of the wound, you have communication from the wound to the joint and a life threatening condition. The good news is modern medicine has made huge advances in the management of infected joints. The bad news is it is not always successful and is very expensive to treat. Infected joints are generally treated by lavaging large volumes of sterile fluid through the joint to flush out the bacteria and the toxins the bacteria produce. This is typically done under general anesthesia. A regional limb perfusion is a procedure that can also be of tremendous value (see Figure 4: A regional limb perfusion of a horse with an infected joint). With a regional limb perfusion the target area of the limb is isolated by one or two tourniquets, and a large dose of a very potent antibiotic is placed in a vessel near the wound. The tourniquet holds the antibiotic near the wound for 20-30 minutes and allows the area to be “supersaturated” with the antibiotic. The levels of antibiotic achieved at the wound are not attainable by conventional routes. Systemic antibiotics will also be a big part of the management of these wounds and are typically given by the intravenous and or intramuscular route as these antibiotics are usually better suited than oral antibiotics. The prognosis for soundness varies tremendously with wounds involving infected joints and are determined on a case by case basis. Lacerations involving tendons are another major cause for concern. The tendons of the distal limb run directly in front and behind the legs. If while examining a wound you notice glistening white tendon like material in the wound, have a handler hold the horse still until a veterinarian can get there as soon as possible. The severity of tendon lacerations depends on location and extent of damage. In general, tendon lacerations of the front of the limb (“extensor tendons”) do well, lacerations involving the tendons of the back of the limb (“flexor tendons”) are serious. Full thickness involvement is obviously more serious than partial thickness ones as is multiple tendon involvement more serious than single tendon involvement. Hindlimbs have a better prognosis than forelimbs with tendon lacerations and infected joints because they don’t have to bear the weight of the head and neck. Flexor tendon lacerations are generally managed with some form of cast or splint and prognosis for full athletic soundness varies but is not typically great (see Figure 5: A splint supporting the back leg of a horse with a severe flexor tendon laceration). In summary, most wounds should involve at least a phone call to your veterinarian, especially if they are near a joint or tendon. Being familiar with basic anatomy will be of tremendous value in helping describe wound location and how serious they are. Have your veterinarian help put together a first-aid kit for your barn or trailer and become familiar with its contents. Doing all the initial steps right are the biggest keys to a successful outcome.

By Laramie Winfield, DVM, DACVIM, cVA, CVMMP Veterinary medicine has changed in recent years, with more practitioners choosing to become board certified in a specific area of practice. This allows us to have a more precise focus in one particular area like surgery or medicine. To best serve your horse's needs, Steinbeck Peninsula Equine Clinics provide veterinarians board certified in multiple different specialties including general equine practice, surgery, internal medicine, and sports medicine and rehabilitation. Learn more about what it means to be a specialist... Learn more about some of our specialtIes: Equiine Practice Internal Medicine Surgery Sports Medicine and Rehabilitation

By Wade Tenney, DVM Published in Bay Are Equestrian Network in June 2007 There was a time when the only practical use of ultrasound in equine medicine was to diagnose pregnancies and bowed tendons. With recent advancements in ultrasound technology, the image quality has improved tremendously. It is now possible to identify subtle injuries and to image parts of the horse that before now could not be seen. In fact, you may be surprised at the number of ways that ultrasound is being utilized in equine medicine. The cornerstone of ultrasound use in equine athletes still centers around the tendons and ligaments that course down the back of the front and hind limbs. These supporting structures are under a tremendous amount of stress during exercise, making them prone to injury. We are able to evaluate the cross-sectional area (size), echogenicity (density) and fiber pattern of these soft tissue structures. Once the injury is diagnosed, recheck ultrasounds (generally at 60 day intervals) allow the veterinarian to evaluate the healing and strength of the injured tendon/ligament. This information allows the veterinarian to constantly adjust and customize your horse's rehabilitation program to prevent re-injury. The evaluation of joints is another important use of ultrasound in our equine athletes. While radiographs (x-rays) give us important information regarding the bony changes within a joint, we need ultrasound to evaluate the soft tissue structures within the joint. Some of the structures we evaluate include the joint fluid, joint lining (synovium), collateral ligaments, menisci and articular cartilage. The joints that we commonly evaluate via ultrasound include the coffin joint, fetlock joint, hock, stifle, elbow, shoulder and even the temporomandibular joint. By combining the information from radiographs and ultrasound, your veterinarian can get a very thorough picture of the condition of the joint. Ultrasound guided procedures have allowed veterinarians to fine tune many diagnostic and therapeutic procedures. Once the target area is visualized with ultrasound, a needle or biopsy instrument can be introduced and visually guided directly to the target area. For instance, ultrasound can guide a needle into deep joints such as the neck or hip so that they may be blocked or treated with steroids. Ultrasound can aid in the biopsy of deep organs such as the lung, liver or spleen. It can also be used to obtain a sample from a deep fluid pocket or internal abscess. One increasingly popular treatment is ultrasound guided injection of stem cells into a core lesion within a tendon or ligament. Without this useful tool, many disease processes would go undiagnosed or untreated. Fortunately, heart problems are not that common in horses. However, if your veterinarian diagnoses a heart murmur in your horse, ultrasound is an invaluable tool to provide information regarding cause and prognosis of the murmur. Ultrasound can tell us which valve is affected and how severe the regurgitant blood flow is. Ultrasound may also help guide the treatment plan; for instance, the treatment will be very different for a heart valve with an infection versus a valve with a degenerative lesion. Some ultrasounds have specialized programs to determine the size of heart chambers, thickness of walls, and the speed of blood through a valve. This information can be used to give a prognosis and potentially help determine if your horse is safe to ride. Ultrasound of the equine abdomen is more commonly implemented, especially in cases of colic, diarrhea, weight loss and liver or kidney disease. On the right side of the horse, ultrasound can visualize the cecum, right kidney, right liver lobe and right dorsal colon. On the left side of the horse, we can evaluate the spleen, left kidney, stomach and left liver lobe. The small intestine and large colon can be seen throughout the abdomen and can be evaluated based on size, motility and bowel wall thickness. Internal abscesses, such as those associated with pigeon fever or Strangles, may also be visualized with ultrasound. In many cases involving eye trauma, examination of the eye may not be possible due to swelling of the eyelids or severe cloudiness of the cornea. Ultrasound allows the veterinarian to evaluate deeper structures and assess the amount of damage within the eye. The iris, lens, optic disc and retina are all readily visible with ultrasound. This allows immediate treatment to begin without waiting for the swelling to subside so that a complete ophthalmic exam can be performed. As you can see, virtually every part of the horse's body can be evaluated to some extent with ultrasound. Ultrasound is a relatively inexpensive and non- invasive means to gather a lot of information regarding disease processes in your horse. So, the next time your horse presents himself as a "diagnostic challenge" ask your veterinarian if ultrasound might shed a little light on the problem...

By Laramie Winfield, DVM, DACVIM, cVA, CVMMP Annual vaccinations are a large part of our preventative health strategy here at Steinbeck Peninsula Equine Clinics. As your veterinarians, we are happy to be one of your main sources of information concerning your horse’s health and vaccines. However, we also realize that many owners would like additional opinions and sources of information. While there are many excellent sources of information available to you on the internet, there are also many sources of information that are misleading, incorrect, and full of misguided advice. The American Association of Equine Practitioners (AAEP) provides a compendium of sound information and Guidelines for Equine Vaccination. Should you vaccinate your horse or not? An article from Horse & Rider titled "Vaccine Wars: The Great Debate" does an excellent job of answering many of the common questions we hear about vaccination and if it is necessary for your horse. We do recognize that some horses are very sensitive to vaccination and alternative vaccine forms and schedules may be best for those horses. Each horse and situation may benefit from a different protocol and we are happy to develop an individual plan for you and your horse. Rabies is a fatal disease that can be transmitted to humans. Given the severity and significance of rabies infection it is included in the core vaccines recommended for horses. The UC Davis School of Veterinary Medicine offers more information in the article "Do Horses Need Annual Rabies Vaccination?" West Nile is a mosquito born viral disease transmitted to horses causing neurologic signs, fever, and in 30% of horses is fatal. Given that available vaccines are highly effective at preventing disease and safe to administer we strongly support the administration of vaccines to protect against West Nile Virus. The California state government monitors new cases an offers a website with updates and more information on West Nile virus.