What you see. The starting point for addressing any equine health related issue is your observation.


Mosquitoes Bothering or Biting Horse


If you notice that your horse is bothered by or being bitten by mosquitos, take prompt measures to stop this. Mosquitoes transmit a number of equine diseases, most notably encephalitis diseases like West Nile Virus. In addition, mosquitos can cause local skin irritation and inflammation. They are also a serious annoyance and, in severe cases, they may bother or distract a horse, resulting in undesirable behavior.

  • Code Green

    Contact Your Vet to Obtain Useful Advice & Resources
    • To discuss your equine's general health and management.

your role


What To Do

Mosquitos are are primarily active at night, and on still, overcast days. They breed in standing water.

Good facilities management to decrease the population of mosquitos is recommended, including the use of fans, screens, and mosquito repellant. Eradicate all pools of low lying stagnant water by cleaning clogged gutters, replenishing water for all pets every three days (at minimum), and stock ornamental ponds with mosquito eating fish.

Likewise, dump, dispose of, or fill all containers (old tires, cans, wading pools, ground holes) that catch and harbor stagnant water. Citronella products are helpful but should be used in combination with other strategies. Keep horse in protected stalls during times of high mosquito activity.

WNV and the encephalitis vaccines are recommended as "core" vaccine by the American Association of Equine Practitioners (AAEP). Frequency of vaccination depends on your geographic region, age and exposure, so talk to your vet about an appropriate vaccination program. Application of mosquito repellents may also prevent or lessen mosquito bites.

your vet's role

First and foremost your vet ensures that your horses are properly vaccinated against appropriate diseases. They may have ideas for management changes and mosquito control to reduce the annoyance from these pests.
Questions Your Vet Might Ask:
  • Is the horse current on vaccines, including encephalitis, West Nile and Rabies?
  • What vaccines (brands, types) were given, and when?
  • Does the horse seem normal to you otherwise?
  • What preventative measures are you currently taking?
  • What mosquito control measures are you currently taking?

Author: Doug Thal DVM Dipl. ABVP