Did you know...?
What Vaccines Does My Horse Need?
When designing a vaccination schedule for your farm, it is important to take into account several important issues.
First, what diseases are prevalent in your area? If the disease is not prevalent, you may not need to vaccinate. It is not only an issue of cost but also potential side effects of the vaccine. Every medication has potential side effects! Never use a product unless the benefits outweigh the risks of an adverse reaction!
Also, consider the severity of the disease: is it fatal or does it just limit the use of the horse for a period of time, such as influenza? Many of our equines are mostly companions to us, and down-time may not be as critical for them as for a racehorse.
Reducing the risk of a respiratory disease by vaccinating for equine herpes (rhinopneumonitis) and/or influenza in a race/show horse is important because the race or show is going to occur only once, while the opportunity of going for a trail ride is virtually unlimited.
Another concern is whether the disease is a year round or seasonal problem. If the disease is seasonal, how long is the immunity provided by the vaccine? This determines the optimal time of year to vaccinate, to provide maximal protection during the high-risk times of the year. Eastern and Western equine encephalomyelitis (EEE and WEE) are good examples of seasonal diseases coupled with a vaccine that doesn’t provide good protection for a full year. If vaccinations are given too early in the year, protection may wane before it is needed most in the late summer and fall. If protection is needed for the entire year, as with a horse that spends its winters in Florida, it will need to be vaccinated twice a year.
There are certain vaccines that all equids require regardless of where one lives in North America. EEE, WEE, west nile encephalomyelitis and tetanus kill horses and occur regardless of your location. Rabies is another disease that may be on the “definitely do” list in certain parts of the country. Vaccination is becoming necessary, especially if your horse travels or has extensive interaction with the public, thus exposing a large population to a potentially infected horse.
A final consideration is economics. If the vaccine is expensive, the ailment isn’t routinely fatal, the vaccine has side effects, and my animal is at low risk of contracting the disease, vaccination may not be warranted.
In general, an initial series of injections is required when dealing with an individual with no or unknown vaccination history. This could be a foal that is just starting its vaccinations or a recently purchased individual of unknown vaccination history. If the foal received adequate colostrum, foal vaccinations are usually started at about 5 to 6 months of age; however, if the foal suffered from a failure of passive transfer (FPT) and did not receive a plasma transfusion, vaccinations may need to be started earlier. Vaccinations of an equid of unknown status may be started immediately.
A booster is required approximately one month after the initial injection. After the booster, a routine schedule is followed, depending upon the specific vaccine administered.
Breeding individuals also present unique challenges. The pregnant mare should be vaccinated about 6 weeks before her due date so she can provide colostrum that is protective against diseases. Often this schedule doesn’t fall at the appropriate time of the year to provide her with protective immunity if the vaccine is not protective for the entire year. WEE and EEE vaccines are again examples of vaccines that may need to be given twice a year if your mare is foaling in the first quarter of the year. Vaccines such as equine viral arthritis (EVA) and equine herpes may also be given to reduce the risk of pregnancy loss. The use, timing and frequency of these vaccines will be resolved by working closely with your veterinarian. Finally, rotavirus vaccine may be given to the mare to protect the foal from rotavirus diarrhea. Vaccinations are also important for the stallion. With the 2006 outbreak of EVA in quarter horses, the use of this vaccine for the breeding stallion needs to be discussed with your veterinarian.
Although a number of the vaccinations can be combined into one injection, the number of injections given may become excessive if many or all of the vaccinations available are given to one individual at one time. To minimize the discomfort and possibility of the horse experiencing a very severe reaction, the number of injections given at one time should be limited to two or three. If more injections need to be given, wait a week and administer the remaining injections.
The majority of injections are given intramuscularly—not all, however. If you are vaccinating your own horses, carefully read the directions for use! Certain strangles and influenza vaccines may be given intra-nasally rather than intramuscularly.
To reduce the risk of an injection reaction, use proper injection sites. If you are administering injections to your horse, be familiar with these sites. The most commonly used sites are the neck, the butt (gluteal muscles) and the hindquarters (semimembranosus and semitendinosus). Never use the neck in a nursing foal! If the neck becomes sore, the foal may refuse to nurse.
There are several sources of vaccines — your veterinarian, feed or tack stores, catalogs, etc. — but the only vaccines supported by the manufacturers are those that are administered or supervised by your veterinarian. When a horse receives vaccines, either obtained from/or given by a veterinarian, one can be certain that the vaccines are produced by reputable manufacturers and have received appropriate handling during shipment and storage prior to administration. Consult with your veterinarian to develop a complete program that is tailored to your farm.
for MHU e-Tips
and email alerts!
My Horse University is a national program located on the campus of Michigan State University and founded by the MSU Department of Animal Science, MSU Extension and MSU Global.
