In light of the high risk of mosquito-borne diseases due to an unusual mix of hot weather and increased rainfall this year, Massachusetts residents are reminded to not only take measures to protect themselves but also domestic animals they may own.  Fortunately for animal owners, there are precautionary measures that can be taken to protect against mosquito-borne diseases like West Nile Virus (WNV) and Eastern Equine Encephalitis virus (EEE), including vaccinations and reducing standing water on properties.

There are effective vaccines for both WNV and EEE available for horses. The best time to vaccinate animals is in May, before the height of mosquito season.  However, since exposures can occur well into October, any unaffected equine can still benefit from the protection of vaccination. It takes several weeks for an animal to be fully protected by a vaccine.  Foals may be vaccinated as early as 2-3 months of age when there is an increased disease risk. Animals infected by EEE and WNV develop neurologic symptoms that can lead to death. There is no treatment for either infection, although supportive care can be provided. In addition to horses, WNV and EEE pose a serious risk to other species, including ratites (e.g. ostrich, emu), pheasants, llamas and alpacas. Owners should consult with their veterinarian about vaccinations.

In addition to vaccination, animal owners can reduce potential mosquito breeding sites on their property by eliminating standing water from containers such as buckets, tires, and wading pools, especially after heavy rains. Horse troughs provide an excellent mosquito breeding habitat and should be flushed out at least once a week during the summer months to reduce mosquitoes near the paddock area. Horse owners should also keep their animals in indoor stalls at night to reduce their risk of exposure to mosquitoes. Additionally, using fans in stable areas may reduce the ability of mosquitoes to land and feed on horses.

Animals diagnosed with WNV or EEE must be reported to the MDAR Division of Animal Health at 617-626-1795, 617-626-1795 and to the Department of Public Health (DPH) at 617-983-6800 or 617-983-6800.