Contagious Equine Metritis (CEM)
Filed under: Bacterial Disease, CEM, Reproduction, Stallion
Tawna Purcell, DVM
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Contagious Equine Metritis (CEM) has been a recent topic of concern for many veterinarians and some owners as of late. CEM, caused by the bacteria Taylorella equigenitalis, was first discovered in England in 1977 and was first identified in the United States in 1978 (in Columbia, MO). The disease was eradicated at that time until it made a brief showing again in 2006 and once again in 2008. Efforts to eradicate the 2008 outbreak are still ongoing.
CEM is highly contagious. Horses are often asymptomatic (no outward sign of infection) although some affected mares can show a mucoid vaginal discharge.
Transmission can occur through direct breeding, artificial insemination of a mare from an infected stallion or contact with items contaminated with the bacteria. Infection results in infertility or abortion in mares, while stallions have no clinical signs. Infertility can last for one or more breeding cycles and certain mares can carry the infection, potentially spreading it to others for many months.
Since the 2008 outbreak was first identified in Kentucky, a number of stallions and a few mares have tested positive for CEM, however some 991 horses, spread over 48 states, have been identified as potentially exposed to the bacteria that causes CEM. Most of these horses have now been tested as negative and the few found positive have undergone, or are in the process of treatment.
Testing of CEM is done in partnership between local and state veterinarians to insure proper methods and future eradication. There are three diagnostic methods available, the most common being bacterial culture in both stallions and mares. Should a mare test positive for the bacteria, a blood test will be done to detect systemic antibodies. Stallions do not develop these antibodies. Stallions who have tested positive, or who have been on a farm with a positive stallion will often undergo a test breeding to negative mares to insure he does not infect them with the bacteria. The process takes 35 days to declare the stallion negative. On average the process to clear a horse takes 6-8 weeks between tests and re-tests.
Although it may seem cumbersome, both mares and stallions can be diagnosed and successfully treated with topical and systemic antibiotics. That along with good hygiene practices will help eradicate CEM from the US once again.
Eye Injuries
Filed under: Corneal ulcer, Emergency, Eye Problems, Laceration, Uveitis
Hunter Ortis, DVM
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The most frequent eye related problems in horses are corneal ulcers (abrasions to the surface of the eye), eyelid lacerations and uveitis. Clinical signs of an eye emergency include excessive tearing or discharge, spasmodic squinting, holding the eye partially or completely closed, or constriction of the pupil. Additionally, changes in appearance of the eye and its surrounding structures such as swelling of the eyelids, increased redness of the usually pink tissue around the eye, and cloudiness of the cornea are signs of an eye problem.
The most common injury of the eye is a corneal ulcer. Ulcers occur when the surface of the eye comes in contact with a foreign object such a hay stem, stick or surface of a stall wall, leaving a defect in the integrity of the surface of the eye. A horse with a corneal ulcer will usually have symptoms of a painful eye and/or a hazy bluish appearance of the surface of the eye. Corneal ulcers are diagnosed with a fluorescing stain applied directly to the cornea during examination. Treatment usually includes topical antibiotics because the cornea is easily infected. Other medications may be indicated on a case by case basis.
Eyelid lacerations are commonly caused when the eyelid simply gets snagged on a piece of stall hardware, an overlooked raised nail or piece of wire. These injuries are much easier to diagnose than most other eye emergencies but are equally important to seek rapid veterinary attention. Most lacerations involving the margin of the eyelid will require repair with suture. The integrity of the eyelid margins is vital for maintaining a proper tear film on the surface of the eye. An irregular eyelid margin can cause recurring and chronic eye irritation.
Uveitis, or inflammation in the interior portion of the eye, occurs when inflammatory mediators are released causing leakage of damaging proteins into the internal structures of the eye. There are many different causes of uveitis including blunt or penetrating trauma, corneal ulcers, systemic diseases, and unknown causes to name a few. Most horses with uveitis will show signs of a painful eye that appears cloudy. Diagnosis is usually made with findings from a complete eye examination including the use of an ophthalmoscope. Rapid and aggressive treatment, often with multiple topical and systemic medications, is essential in minimizing the possibility of permanent damage to the internal structures of the eye.
Injuries of the equine eye should be considered an emergency, and owners should consult their veterinarian immediately when a potential problem has been identified. Delaying treatment or instituting improper treatment on some ocular conditions can lead to permanent damage to the eye and loss of vision.
Cellulitis
Filed under: Cellulitis, Emergency, Joint, Laceration, Lameness
Nathan Voris, DVM
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Anyone with a horse has likely walked out to find them with a swollen, painful leg. While there are countless reasons for a horse to become “stoved-up” or “stocked-up”, one of the most common is cellulitis.
Cellulitis can be literally defined as inflammation of subcutaneous tissues. Many times, a cause for the swelling cannot be found, but some common reasons for cellulitis include “scratches” (pastern dermatitis), blunt trauma, lacerations or small puncture wounds. Inflammation, with or without bacterial infection, that is trapped under the skin, is clinically expressed as heat and swelling of the affected tissues thus resulting in a swollen, painful leg. Many times the horse will be severely lame and might even have a fever.
Treatment of cellulitis often includes hydrotherapy, sweat/pressure bandaging, anti-inflammatories and antibiotics. Efforts should be made to find the inciting injury as other diagnostic tests or treatments might be required to adequately treat the horse’s condition and to check the integrity of underlying bone and soft tissues.
2009 Newsletter
Printed copies of the 2009 Equine Medical Services newsletter have been mailed. If you didn’t receive a copy, or if you would like a digital copy to share with friends, the on-line version can be found at the following link:
http://www.equmed.com/2009%20EquineHealthUpdate.pdf.
If you would like a printed copy mailed to you, please let us know and we will add you to our list.
AAEP 55th Annual Convention
Dr.’s Rob Foss, Paul Schiltz, Nathan Voris and Tawna Purcell attended the American Association of Equine Practitioners Annual Convention, the world’s premier continuing education meeting for equine veterinarians. The convention, held in Las Vegas, NV, December 5-9, offered veterinarians the latest advances in equine health care. Scientific sessions covering topics ranging from critical care to lameness were attended by an international gathering of over 2,500 veterinary professionals. Many of the sessions focused on providing new equine health care techniques that can be applied immediately to a veterinarian’s daily practice.
The American Association of Equine Practitioners, headquartered in Lexington, KY, was founded in 1954 as a non-profit organization dedicated to the health and welfare of the horse. Currently, the AAEP reaches more than 5 million horse owners through its nearly 10,000 members worldwide and is actively involved in ethics issues, practice management, research and continuing education in the equine veterinary profession and horse industry.
You’re invited to visit the new and improved equmed.com
Equine Medical Services is proud to announce the launch of a more user friendly, feature rich website. Scroll down for a tour of the new site.
Our popular Foal Due Date Calender has been improved to accommodate all browsers and operating systems.
With the new calendar format, simply chose the month of the mare’s last breeding date and click “Go”. The calendar will update and you can choose the specific date. You will note that if you hover over the date, the expected foaling date will show up in the yellow box. If you click on the date, a printable form will open that contains the expected foaling date along with the recommended date for removing fescue from your mare’s diet and important vaccination dates.
As mentioned above, the new equmed.com is highly user friendly. A new feature to the website is a search box in the upper right hand corner. Simply type any keyword into the box and press “Go” to search the entire EMS website for information concerning your search. A second way to search for EMS articles is to use the dropdown box on the sidebar under “Articles”. Here you will find categories of horse health articles published by the staff of Equine Medical Services.
In addition to articles written by our staff, you can keep up with current national and world news involving horses on the far right sidebar of the website. The content of this sidebar comes from various reputable web resources and is updated daily.
Finally, you can stay up-to-date with equine news and be the first to receive articles written by the veterinarians at Equine Medical Services by signing up to follow us on Twitter, Facebook, or by subscribing to our RSS feed. If you are not comfortable with these formats, you can sign up to receive our articles via email.
We hope you enjoy our new website! Let us know if there is anything you would like for us to add or improve.
Introduction to Acupuncture
Dr. Tawna Purcell
Acupuncture; the word usually induces a raised eyebrow and skeptical look however the benefits of this treatment modality are numerous. Acupuncture, like all medicine, has been evolving over the last 3000 years and is currently used along with Western Medicine throughout much of the world. It gained the most recognition in the United States after Richard Nixon’s visit to China in the 1970’s. During this visit an American journalist traveling with him developed appendicitis and had to have the offending appendix removed. The interesting and impressive factor to this surgery was that the anesthesia was performed using only acupuncture. Due to recent public awareness, there has been an increase in research and thus an overall understanding of the physiologic mechanisms of acupuncture.
Where to start:
The Diagnostic Acupuncture Exam (DAPE) is a thorough exam evaluating the entire horse from head to toe. Combined with our western physical/lameness exam, DAPE provides a very comprehensive examination in determining the most beneficial treatment plan. Acupuncture is an excellent compliment to Western Medicine for providing additional overall pain control, enhancing management of chronic diseases and speeding the healing time from acute injuries as well as post-operative recovery.
Why Stick Needles to Improve Pain:
How can a few tiny needles placed in apparently random spots in the body possibly help healing or pain? It is a curious question to most of us. However if one studies anatomy and nerve pathways, acupuncture points start to make more and more sense.
Acupuncture provides neuromodulation of sensory nerves. Points are identified as locations where nerve bundles penetrate fascia, locations where nerves come up through the muscle (closer to the skin) in close proximity to blood vessels or as trigger points. When a needle is placed into one of these areas it causes micro-trauma and induces a neurovascular reaction, capillary dilation and tissue repair activation. This reaction stimulates the local nerve branch which communicates to the central nervous system telling it to heal along the nerve and to the site of the needle stick. In doing this, the nerve is also sending impulses to every one of its branches (to specific muscles and organs for example) increasing their neuroactivity and stimulating the brain to release various hormones and transmitters which affecting the body by reducing pain, inflammation and normalizing circulation.
Trigger points are areas of marked pain in the myofacial layer caused by prolonged muscle tension, spasms, or are the result of inflammation. Trigger points are easily palpable as a hard, painful nodule or knot. Trigger points weaken and prevent full lengthening of the muscle. This decreases the amount of blood in capillaries, decreases the amount of oxygen delivery and causing tissue hypoxia (lack of oxygen). This is a painful condition, but one that can be treated in a few sessions or less.
Techniques:
There are many ways to stimulate acupuncture points. Among the most common are dry needling, electro-stimulation and aquapuncture. Dry needling is the insertion of needles augmented only by manual manipulation. Electro- stimulation is applying a mild electrical current to dry needles in order to influence deeper pain fibers and structures. Aquapuncture is the deposition of small amounts of vitamin B12 or sterile saline into the area of an acupuncture point. This allows for constant stimulation of the point and is often used in more chronic pain treatments.
How does it feel and is it safe:
Having had acupuncture myself I can tell you the feeling varies on where the needle is placed. The actual placement of the needle can feel as strong as a pin prick or go completely unnoticed. Certain horses will react differently depending on their personality and degree of pain. The sensation of the needle after placement can be a dull ache or mild cramping and a sensation of an impulse “traveling” up the nerve. The needles used are sterile, very thin (0.2-0.3mm) and side effects are extremely rare. The number of treatments required will depend on the medical condition and how long it has been present. Each treatment is between 5 and 30 minutes.
It should be mentioned that acupuncture is not always a treatment modality on its own, but an adjunct treatment that in combination with Western Medicine can often improve the outcome considerably. One should always first pursue a good diagnosis prior to or during an acupuncture exam.
New Foal Exams
Nathan Voris, DVM
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One of the most important things a proud owner of a new foal can do is have their veterinarian examine the new arrival between 12 and 24 hours after it is born. Of course, the mare and foal should be examined sooner if the owner has any concerns about their well-being. Things that should raise immediate concern include the following: the foal has not stood within 2 hours of birth, nursed within 4 hours or the mare has not passed the placenta within 6 hours. Additionally, any signs of distress in either the mare or the foal should be examined immediately.
Thankfully, most of the time none of the previously mentioned ailments are present. However, there may still be an invisible problem, one that would not reveal itself for several days, one that can be readily diagnosed and subsequently addressed via a simple stall-side blood test. The often unseen problem is Failure of Passive Transfer.
Foals are born with a naive immune system; it does not recognize, and is therefore not able to respond to disease causing agents (viral or bacterial). Antibodies in the first milk of the mare (the colostrum) are absorbed into the foal’s blood stream which transfers the protection of mare’s immune system to the foal. A foal has usually absorbed a sufficient quantity of colostral antibodies by the time it is 12 hours old, but can continue to absorb for up to 24 hours.
Veterinarians can measure the extent to which a foal has absorbed colostral antibiodies through a blood test that measures Immunoglobin G (IgG). A foal is born with an IgG level of zero. There are defined IgG levels that are believed to be indicitive of protective transfer of immunity. Test kits have been developed that measure the foal’s IgG, stall side, in about 5 minutes.
Foals with inadequate transfer of passive immunity will eventually get sick. Many will succumb, as would any other immune compromised individual, when confronted with a serious bacterial or viral agent. Diagnosis of FTP between 12 and 24 hours of age gives veterinarians an opportunity to correct the deficiency through intravenous infusions of hyper-immunized equine plasma before the foal’s immune system is tested.
The investment of time, energy, emotion and financial resources is considerable when it comes to planning for a new foal. Attention to the foal’s immune system during a routine new foal check-up can help reduce unwanted setbacks in the foal’s development and additional expense in treating a very fragile animal.
Ever Heard of HERDA?
Nathan Voris, DVM
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The acronym HERDA stands for “Hereditary Equine Regional Dermal Asthenia” and represents a rapidly emerging genetic disease within the Quarter Horse industry. HERDA has a strong familial basis that has been identified in the bloodlines of Poco Bueno (AQHA 3034).
HERDA causes the skin to separate between the superficial and deep dermal layers resulting in excessive stretching, weakness and tearing of the skin. Locations involved often include the skin over the back, but can affect the entire horse. Clinical signs can be apparent at birth, but are commonly not noticed until the horse is being broke to ride.
The disease is caused by a homozygous recessive gene. Reaching back into my memory of Mendelian Genetics and Punnet Squares, a horse has to have two copies (homozygous) of the recessive allele, one from each parent, to be affected. To put it in terms easier to understand, a non-carrier bred to a carrier will not result in an affected foal, but will produce a carrier 50% of the time. Alternatively, a carrier mare (Hh) bred to a carrier stallion (Hh) would have a 25% chance of producing a homozygous negative (HH), non-carrier-normal foal; a 50% chance of producing a heterozygous (Hh) genetic carrier-clinically normal foal; and a 25% chance of producing a homozygous recessive (hh) affected foal.
There are at least two labs currently offering a DNA test that reveals a horse’s HERDA carrier status. The test can be performed on hair or blood, is relatively inexpensive. Owners of popular stallions are advertising their horse’s HERDA status in an effort to control the spread of this terrible genetic disease. Knowing the genetic status of the mare and stallion prior to breeding can help guide the pairing decision process and eliminate the uncertainty of producing an affected HERDA foal.
Choke
Hunter Ortis, DVM
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Choke (equine esophageal obstruction) is a common problem caused by impaction of food material in the esophagus. Unlike human choke, horses are able to breathe during a choking episode because the trachea (windpipe) is not involved. However, this does not mean swift medical attention is not needed. Choke can occur in any horse at anytime but occurs more commonly in horses that have improper mastication (chewing) due to poor dentition, are greedy eaters or are on a pelleted ration.
Horses with choke will usually look depressed and stand with their neck outstretched, have a nasal discharge containing saliva and feed material, salivate excessively, cough repeatedly and make frequent attempts to swallow. If a horse is suspected to be choking, feed and water should be removed to prevent further impaction of feed material in the esophagus.
Treatment of choke usually involves administering a sedative and oxytocin. The combination of the sedative and oxytocin causes relaxation of the esophageal musculature and lowers the head of the horse to facilitate lavage. Once the horse is sedate, a nasogastric tube is passed to the location of the obstruction. Water is gently pumped through the nasogastric tube to break down the obstruction. Water and feed material are often expelled from the mouth and nasal passages during this procedure. Verification that the choke has been resolved is made when the nasogastric tube passes through the entire length of the esophagus, into the horse’s stomach.
Once the obstruction has been resolved the horse should be held off feed for 12 hours and allowed free choice water. A diet of fresh grass or complete pelleted feed slurry is recommended for the next few days. Anti-inflammatory drugs and antibiotics are often recommended due to irritation that may have occurred from the obstruction and the possibility of pneumonia from aspiration of materials during the choke.