With spring approaching in Wisconsin, horse owners are starting to think about immunizations or vaccinations as well as other spring preventative health care for their horses. Historically, “spring preventative health care” has included vaccinations, dental checkups, fecal parasite evaluations and annual Coggins testing as well as annual wellness checkups. This can create a sizeable veterinary bill all at once. Some horse owners wonder if this work can be spread out over more time to lessen this financial blow as well as whether it’s all needed in the spring. The answer is yes and no. Read on to find out why.
Written By: Dr Lisa Nesson (pictured on the right)
With the change is Wisconsin’s regulations regarding the frequency of testing for equine infectious anemia (or a Coggins test) from within the calendar year to within twelve months, Coggins testing can be done anytime throughout the year. The resulting negative test will be good for a full twelve months after the date the blood was drawn. So, a test drawn on September 22, 2022 is good until September 22, 2023. This gives horse owners more uniformity with surrounding state’s EIA (Coggins) testing requirements.
Dental checkups are important for all horses, regardless of age. Every horse should have an oral exam at least annually, if not semiannually, with dental work (floating or equilibration) done as dictated by the condition of each individual horse’s needs. This work can be done at any time of the year. Having said that, here in Wisconsin, dental work is difficult to impossible in periods of extreme cold if you don’t have a heated or well insulated facility. Your veterinarian and your horse would appreciate it if this work was done before or after the arctic weather of December through February unless you have the housing to make it comfortable for everyone, including the equipment, involved.
Annual wellness examinations should be done prior to periods of increased physical expectations such as going into training or the start of the performance season, whether that be trail riding or showing. These are often done in the spring for performance horses or the fall for young horses just starting their training. They should also be done when issues are noticed - be that weight loss or gain, illness, lameness or poor performance. These examinations, or at least a mini exam, are frequently tied to vaccinations because your veterinarian wants to be sure to only vaccinate a healthy horse. The timing of your individual horse’s exam should be discussed with your veterinarian.
Fecal parasite evaluations should be done prior to the grazing season in the spring. So, in Wisconsin, a fecal egg count is recommended in March or April. This allows for the deworming of the moderate to high shedding horses prior to going out onto pastures so the parasite contamination of the pastures is minimized during the grazing season. Fecal egg counts may be repeated in the fall for monitoring the shedding levels of the herd.
Horses are typically immunized or vaccinated once to twice a year, depending on the vaccines being given, the exposure level and timing of exposure of the individual horse or the herd. The core vaccinations outlined by the American Association of Equine Practitioners (AAEP) include Eastern and Western Encephalomyelitis, West Nile Virus, Tetanus and Rabies. All of these vaccines are annual vaccinations so they are considered to induce immunity that will last a full year so only need to be given once a year. Eastern, Western and West Nile viruses are all spread by mosquitoes so these vaccinations should be given prior to the mosquito season in the spring so that the horses have their highest level of immunity during the time of year when their exposure is the greatest. Some veterinarians recommend they be given twice a year in parts of the country that have mosquitoes year-round, but there is debate about whether this is necessary given the length of immunity these vaccines have been shown to produce. Tetanus and rabies don’t have seasonal vectors so these vaccines can be given anytime throughout the year. That being said, Eastern and Western Encephalitis vaccine is not available without Tetanus so this combination along with West Nile virus should be given in the spring prior to mosquito season. Rabies vaccine is available by itself or in combination with other vaccines such as Potomac Horse Fever and EEE/WEE/Tetanus/WNV (Eastern & Western Encephalitis, Tetanus & West Nile Virus) so when Rabies in given will depend on whether it is being given alone or in combination with these other vaccine strains.
The commonly given risk-based vaccines outlined by the AAEP include equine influenza, rhinopneumonitis, strangles, and Potomac horse fever. Influenza and rhinopneumonitis vaccines typically produce protective immunity of shorter duration (3 to 6 months) and therefore need more frequent boosters based on the level of expected exposure of the horses being vaccinated. These diseases are also spread through horse-to-horse contact, as is strangles. Horses living in boarding barns or on farms where horses are traveling to shows or other events where horses come in contact with each other should be vaccinated semiannually. Typically, the first booster of the year is given prior to the travel scheduled for the horses, so prior to the performance season and the second booster is 6 months or so later. If your horses have little to no exposure to other horses and they don’t travel off your farm, you may not need to vaccinate for influenza, rhinopneumonitis or strangles at all, or may choose to vaccinate just annually. The strangles vaccine is an annual vaccine and this disease is spread by horse-to-horse contact so it only needs to be done once a year and should be done prior to the time of anticipated exposure to other horses. Potomac Horse Fever is spread by horses eating infected cicadids, an insect that lives near standing water. It is not spread horse-to-horse. The Potomac Horse Fever (PHF) vaccine, which is labeled as an annual vaccine, is more efficacious if it is given twice a year. It should be given in May prior to the vector season and again in late summer (August) for the horses to get the best benefit from the vaccine. Use of the PHF vaccine should be discussed with your veterinarian based on the geography of your farm and the efficacy of the vaccine in preventing disease.
The timing and need for other risk-based vaccines should be discussed with your veterinarian.
So, as you can see, some “spring” work can be spread out throughout the year. Fecal evaluations and several vaccinations should be done in the spring, not winter, of the year to afford your horse the best protection against those diseases.
