flu | Horse Racing Free Tips

Don’t Hesitate To Vaccinate For EHV With Other Core Vaccines

With the onset of the most serious EHV-1 outbreak Europe has seen in years, horse owners and caretakers are reminded of the necessity of vaccinating horses against the deadly disease. Questions have arisen regarding the best timing of vaccine administration — should the EHV vaccine be given concurrently with other AAEP-recommended core vaccines or should the vaccines be split into multiple doses?

Research suggests that vaccinations for equine influenza virus (EIV) and equine herpesvirus types 1 and 4 (EHV-1 and EHV-4) can safely be administered on the same day without compromising the horse's immune response.

Scientists from the Irish Equine Centre in Kildare divided 30 healthy horses into two groups to test the efficacy of the vaccines alone and used in tandem. The first group received the EIV vaccine and then a combination EHV-1 and EHV-4 vaccine two weeks apart. The second group was given both vaccines on the same day. Blood samples were taken from all horses before and after the vaccinations to measure antibody levels to EIV, EHV-1 and EHV-4.

Results showed that the horses vaccinated for both EHV and EIV on the same day had slightly higher antibody response to EIV vaccines than those horses that were vaccinated two weeks apart. There was no significant difference in EHV-1 and EHV-4 antibody response between the two groups.

The study team concludes that administering EIV and EHV-1 and -4 concurrently will not compromise the horse's immune system response.

Horses May Need Up To Three Weeks Of Recovery After A Virus

It's not just humans that should take it easy if they're ill: experts say horses that have had the flu or other respiratory issues should rest for at least three weeks to allow their bodies to heal. Though lower-level exercise isn't necessarily harmful, high-intensity exercise can suppress immune system response and increase the horse's susceptibility to disease.

Intensely exercising a recovering horse can also cause him to lose weight and tire more quickly, as well as have a harder time recovering. Exercising does not affect virus duration or the duration of virus shedding.

It takes a minimum of three weeks for the respiratory epithelium and the mucociliary apparatus to heal, so allowing horses to rest or complete only low-level exercise is imperative. If exercise is begun and the horse seems distressed, it should be stopped immediately. Open communication with the treating veterinarian is key to creating a return-to-work plan tailored to the horse and his specific health issue.

Non-Compliance Of Flu Vaccine Administration Leaves Horses Vulnerable

Horses in the United Kingdom may be at risk of the flu even if they are vaccinated because of non-compliance with manufacturing guidelines, research shows. Drs. Amie Wilson, Gina Pinchbeck, Rachel Dean and Catherine McGowan created a survey that asked equine vets in the UK to describe their vaccination practices. The study team then compared these protocols with manufacturer guidelines and datasheets.

Of the 304 responses, 92 percent indicated that the recommendations they give owners are not consistent with manufacturer guidelines for administering the vaccine. Vets most often used vaccination guidelines from the British Horseracing Authority and the Fédération Equestre Internationale.

Additionally, there was variation in vaccine booster protocol for competition and noncompetition horses. The most recommended strategy, given by 57 percent of survey respondents, was a 6-month flu vaccine shot for competition horses and annual flu vaccine administration for non-competition horses.

Nearly 86 percent of vets reported that their clients were reluctant to administer vaccines because of fear of over vaccination, cost and the potential for adverse reactions. Of the vets who responded, 66 percent had horses that experienced an adverse reaction to vaccination, but only 19 percent of these vaccination reactions were reported to the Veterinary Medicines Directorate. Most reactions included stiffness, swelling, lethargy and fever.

The study team noted that there is a discrepancy between manufacturer guidelines for flu vaccinations and those issued by governing bodies for equestrian sport and racing. Non-compliance is common, leaving horses at risk for getting the flu.

Read the study here.