(HARTFORD, CT) – The Connecticut Department of Agriculture (CT DoAg) is reminding the state’s horse and livestock owners to take preventative measures to protect against mosquito-borne diseases, including West Nile virus (WNV) and eastern equine encephalitis (EEE). Both diseases pose a risk to animals and humans, with two confirmed West Nile virus detections in Connecticut residents this year. The Connecticut Agricultural Experiment Station has reported an increase in WNV-infected mosquito detections in recent weeks. No horse or livestock detections have been confirmed in 2026.
EEE and WNV are both mosquito-borne diseases affecting horses, birds, and humans. Horses are the domestic animals most susceptible to infection from EEE and WNV, however other animals such as llamas, alpacas, and goats can also be infected. The viruses cannot spread through animal-to-animal or animal-to-human contact. It is a viral disease transmitted through the bites of mosquitoes. The risk for mosquito-borne diseases continues until the first hard freeze ends mosquito activity.
“As mosquito activity increases taking proactive steps to protect animals, and the people caring for them, over the next few weeks is of utmost importance,” said State Veterinarian Dr. Thamus Morgan, DVM, MPH, DACVPM. “Prevention starts with sound barn management practices to reduce mosquito populations and preventing bites, in consultation with your veterinarian to administer recommended vaccinations and boosters.”
To prevent mosquito-borne diseases in horses, and other animals, caregivers should:
- Consult with a veterinarian on vaccinations for mosquito-borne diseases
- Remove sources of standing water (i.e. puddles, tires, etc.) and empty and refill water buckets daily
- Keep animals in the barn with fans on and pets inside the home from dusk to dawn
- Apply fly sprays containing pyrethrin regularly
“We know that owners and caregivers are already doing a lot to keep their animals healthy – these mosquito prevention methods fit naturally into daily routines while being low or no cost and taking minimal extra time,” said Agriculture Commissioner Bryan P. Hurlburt.
If you suspect your horse may have EEE or WNV, contact your veterinarian immediately to determine a diagnosis and treatment. They are both reportable diseases to the State Veterinarian at 860-713-2505. Signs of mosquito-borne diseases include neurologic symptoms, such as hyperexcitability, tremors, convulsions, paralysis, head tilt, or incoordination. For more information on animals and animal health, visit the state website.
About Connecticut’s Mosquito Management Program
The State of Connecticut Mosquito Management Program is a collaborative inter-agency effort involving the Department of Energy and Environmental Protection (DEEP), the Connecticut Agricultural Experiment Station (CAES), the Department of Public Health (DPH), the Department of Agriculture, and the Connecticut Veterinary Medical Diagnostic Laboratory (CVMDL) at the University of Connecticut (UCONN). These agencies are responsible for monitoring mosquito populations and the potential public health threat of mosquito-borne diseases.
For information on WNV and EEE, what can be done to prevent getting bitten by mosquitoes, the latest mosquito test results, and human infections, visit the Connecticut Mosquito Management Program website.
