Potomoc Fever


It’s that time of year again!

It’s been a long wet summer, and we have been starting to see horses with Potomac Horse Fever(PHF) here at WVC.

Potomac horse fever is a potentially fatal gastrointestinal disease that strikes in the late summer months. The disease is infectious, but not contagious between animals. It can effect any breed, sex or age of horse.

It is a disease caused by a microscopic bacteria that grows and multiplies in fresh water. The bacterium, called Neorickettsia risticii, has a critical step in it’s lifecycle that involves snails and insects. It is suspected that horses ingest the insect and bacteria accidentally while drinking standing water or grazing nearby.

While the most common signs of PHF are fever accompanied by loss of appetite, lethargy, and severe diarrhea. Here is a list of the many clinical signs. 
• Depression
• Anorexia (not eating)
• Fever
• Colic
• Soft manure/diarrhea
• Dehydration
• Laminitis
• Abortion (occasional)
• Death

Prevention includes limiting exposure to freshwater streams, ponds, dugouts, or other natural water sources especially when insect activity is at its peak. There is a vaccine available; however, PHF has many different strains, which can cause the vaccine to fail as there is only a single strain in the vaccine.

PHF progresses quickly and can be fatal, however it can be treated. Survival rates depend strongly on quick intervention. If you notice your horse is a bit “off” or is showing the above signs of PHF give us a call.