Tennessee’s state veterinarian confirms four horses in Tennessee have now tested positive for Potomac Horse Fever (PHF). Cases in Hawkins, Robertson, and Sullivan counties are in addition to the Wilson County case announced earlier this month where a horse was diagnosed with PHF and had to be euthanized.
State veterinarians say the disease can be prevented with regular vaccinations and providing clean drinking water. They say one way to do this is change from natural drinking water sources to frequently-cleaned water buckets.
Vaccination for PHF should be administered before mid-to-late summer when the risk of illness is increased. The vaccine provides protection and minimizes the severity of disease if a horse is infected but does not always prevent a horse from getting PHF. Horse owners should work with their veterinarian to determine an appropriate vaccination schedule.
PHF is caused by a bacteria thought to be carried by aquatic snail larvae and other intermediate hosts including flies. Horses that live near bodies of water or low-lying areas that could collect stagnant water are at risk. In addition to clean drinking water, horse owners can reduce risk of exposure by turning off insect-attracting stable lights at night.
PHF is not a threat to human health and it is not contagious between horses. Horse owners should watch for signs that can include anorexia, diarrhea, colic, fever, and laminitis. Signs of the disease can appear in 2 to 18 days after ingestion and can be fatal if left untreated.