2002 Winter 

Vaccine Vexation

I am often asked questions about vaccines. As clients you are curious about what the vaccines are actually protecting your horse against, what vaccines are necessary, which ones I recommendthe list goes on and on. Some people simply tell me to "give my horse everything" while others ask me to "give my horse only what he needs". Hopefully, after reading this article you will have a better idea of what your horse needs to be protected against and the diseases he may face. The following are a list of the common vaccines that can be administered to your horse.

Tetanus Toxoid, Eastern and Western Encephalitis- Although this is actually three different diseases, it is often combined together into one convenient vaccine. Tetanus is a highly fatal disease. Your horse is exposed to tetanus bacteria when he has an open wound. The bacteria can be found anywhere in the horse's environment, on nails, boards, or even in the soil. Once inside the bacteria can release a toxin that attacks your horse's nervous system resulting in muscle spasms, paralysis and eventually death due to respiratory and heart failure. It is for this reason I will ask when your horse's last tetanus vaccine was given when I am treating an injury. If your horse gets an injury and it has been several months since his last tetanus vaccine, it should be updated. Tetanus vaccines are given once a year (unless an injury causes another to be given) and would be more ideal to give in the spring due to higher exposure to the bacteria during the warmer months as well as the vaccine being combined with protection against encephalitis. The reason that combination is significant is because Eastern Encephalitis and Western Encephalitis are viruses that attack the brain and nervous system which can result in severe neurological disease and even death. These viruses are spread by mosquitoes. Therefore, this vaccine should be given directly prior to the mosquito season. Since all three diseases covered in this combination vaccine are more prevalent during the warmer months, it is recommended that this vaccine is given in the spring.

Influenza / Rhinopneumonitis­ Again, this vaccine is a combination vaccine of two separate diseases. Influenza is a virus, just like us when we get influenza or the "flu", horses can experience fever, depression, loss of appetite, nasal discharge and coughing. Although it is rarely fatal, it can be very contagious and it often results in a long recovery period causing your horse to lose time from training and showing. Influenza vaccine is a shorter lived vaccine; therefore, it is often given at least twice a year (in spring and fall). In young horses that are frequently traveling to shows and such, vaccines can be given as often as every three months. Rhinopneumonitis is the name for Equine Herpesvirus. There are two different types of Herpesvirus: Type 1 that can cause abortions in pregnant mares and neurologic and upper respiratory diseases in affected horses and Type 4 that causes mainly upper respiratory disease. Since it is a combination vaccine, Rhinopneumonitis vaccine is usually given every 6 months along with the influenza. In pregnant mares, there is a different type of Rhinopneumonitis vaccine that specifically contains Type 1 to help prevent against infectious abortions. This Type 1 vaccine is administered during months five, seven and nine of pregnancy.

West Nile Virus­ After our last newsletter and all the information everywhere about West Nile Virus I am sure I could skip talking about this vaccine. As a recap, West Nile Virus is a virus that is spread by mosquitoes and affects the horse's neurological system. I have witnessed clinical signs ranging from mild muscle tremors to horses walking "drunk" or unable to stand. Last year, Indiana reported over 700 cases of West Nile Virus in horses. Since this virus is spread by mosquitoes it is imperative that your horse gets vaccinated four to six weeks PRIOR to the mosquito season. If your horse did not get the vaccine last year you should start vaccinating your horse over two months prior to the mosquito season-to insure the second vaccine (given 3 weeks after the first) is given four to six weeks before any mosquito exposure.

Rabies­ Rabies is a virus that is spread through bodily secretions of infected animals (e.g. saliva). This virus is always fatal; there is no available treatment for rabies once contracted. The virus attacks the nervous system causing several progressive neurological symptoms that eventually lead to death. Rabies is considered endemic in the eastern states and the "spread" of the disease has been working this way for quite sometime. It got just about half way through Ohio before they got it back under control with wildlife vaccination programs. It is for this reason, and the close proximity of the problem area, that the veterinarian associations began recommending vaccinations to any companion animal (including horses). It is state law to vaccinate your cats and dogs, but it is simply highly recommended to vaccinate your horse. If any vaccinated animal is apparently bitten by an unknown animal, it is important that you booster his rabies vaccination as soon as possible.

Potomac Horse Fever- Potomac Horse Fever is the layman's name for equine ehrlichiosis which is caused by a bacteria-like microorganism called Ehrlichia risticii. The first horses that developed this condition back in 1979 were living along the Potomac River, thus the name Potomac Horse Fever came in to play. The organism attacks the horse's monocytes (a type of white blood cell) and the cells that line the large intestine. Clinical signs often include high fever, depression, colic, severe diarrhea and sometimes laminitis (founder). The exact way it is spread is still unknown, but ticks, fleas, flies, beetles and snails have and are being investigated. It is not contagious so it will not spread from horse to horse. Most cases of Potomac Horse Fever are seen in late summer, between July and September. Therefore, it is important you vaccinate your horse in the spring before this period of time.

Intranasal Strangles- Strangles is the layman's name for disease caused by Streptococcus equi in horses. In this horse's version of a strep throat, the bacteria settle in the lymph nodes at the back of the throat and under the jaw and cause them to turn into pus filled abscesses. Once the abscess gets large enough they burst open and drain. The term strangles came from the swelling causing the appearance of the horse being strangled and resulting in respiratory distress. The disease is highly contagious, the draining discharge from the abscesses and usually from the nose is filled with the bacteria and can easily be spread from horse to horse by direct contact, by you walking in and touching the horse and touching another horse, from pitchforks, shoes, etc The vaccination used to be a muscle injection but now the more common vaccine to use is the intranasal (squirting the vaccine up the nostril) vaccine. It stimulates an immune response in the back of the throat where it is needed and not through the entire body. Strangles is not like "chicken pox" ­every horse does not need to get it at some point in their life and they are not protected for life once they do. Once they contract it, they probably have the equivalence of a vaccine but should be revaccinated the following year. If your horse has had the disease or has been exposed to it, the vaccine may be skipped for that year to not over stimulate the horse with the bacteria. The disease is usually more prevalent in younger horses, but can be contracted in any age of horse.

There you have it, the most commonly used vaccines in a nutshell. Our recommended vaccination schedule is as follows:

Another consideration is pregnant mares and foals and when to vaccinate them. The most successful way to transfer antibodies to a newborn foal is to vaccinate the mare with your desired vaccines four to six weeks prior to delivery. By vaccinating the mare, her first milk (the thick, sticky colostrum) will be high in the antibodies for the vaccine and will pass immunity to the foal. The foal will have those maternal antibodies circulating in his/her bloodstream for several months. The maternal antibodies will interfere with any vaccines given before six to seven months of age; therefore your foal should be vaccinated starting around that time.

Wellness Packages

Our Wellness Package is now finalized and you can find it on our website by clicking here or you can contact us for more information. It is a wonderful way of knowing your horse has received all his veterinary care for the year without worrying about the small details. All of the necessary vaccines discussed in the previous article are covered in the Wellness Package along with annual physical examination and dental work.

Impaction Prevention

This is the time of year for the wind to blow, the temperatures to be low and the water to be frozen. With the cold temperatures horses tend not to drink as much water as they would during more temperate weather, and sometimes they can get a bit dehydrated which results in them being "constipated" or impacted. Impacted horses sometimes act mildly colicky-not wanting to necessarily eat but also not being overly uncomfortable (i.e. rolling, kicking at their sides, etc) as you would expect a true colic to be acting. They usually respond very well to pain medication (e.g. Flunixin Meglumine or Banamine®) and will begin eating once administered, but will then go back to not eating once the medication wears off. Impactions can generally be palpated in the colon with a rectal examination and once discovered can usually be treated medically. Treatment generally consists of fluids, fluids, fluids andoh yes, more fluids. A large bolus of fluids given both intravenously (IV) and through the stomach tube with a pump at one time is usually just what is needed to loosen up the impaction and send it out on its merry way. Treatments over the course of two to three days are sometimes required. Some impactions can get more severe; however, and may require 24 hour IV fluid therapy or possibly even surgery. In general, the earlier the intervention the quicker the response to treatment. Prevention of impactions usually revolve around adequate hydration. I understand the old adage ­ you can lead a horse to water but you can't make them drink-but there are a few things that we can try to entice them to drink a bit more during the colder months. Heated water troughs or water buckets will not allow water to freeze and allow constant access to water for the horses during the cold months. Offering warm water to horses at meal times (especially horses prone to impactions in the past) is also a good practice. If you see any clinical signs that resemble an impaction, remember early intervention is the key. Call for further medical treatment.

Happy Birthday

As we all know, January 1st is the universal birthday for all our beloved equine companions. So why not celebrate with a birthday party? Here's a recipe for a carrot cake. This was taken from "The Ultimate Guide to Pampering Your Horse". (They deserve it every once in a while don't they?)

Carrot Cake ­ 1 c. sugar, 1 c. light brown sugar, 1 c. flour, 1 c. bran, 1 t. baking powder, 1 t. baking soda, 1 t. cinnamon, 3 c. carrots - grated, 1 1/2 c. corn oil, 4 eggs, 2 t. vanilla extract, 1 apple - cut into six pieces

Preheat oven to 325 and grease 13X9 baking pan. In a separate bowl, mix dry ingredients and then add carrots, oil, eggs, and vanilla. Beat until there are no lumps. Pour into prepared baking pans and bake about 1 hour. Remove from pan when cool. Garnish with apple slices and sprinkle with brown sugar. Serve cool. ENJOY!

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Something Cute...

At the link below, wait for the entire screen to load up with all four horses and a fence in front of them. Then click on each horse. Re-click on any horse to make it turn off or turn it back on again. Enjoy!

http://svt.se/hogafflahage/hogafflaHage_site/Kor/hestekor.swf