Potomac horse fever

It was first described in areas surrounding the Potomac River northwest of Washington, D.C., in the 1980s, but cases have been described in many other parts of the United States, such as Minnesota, California, and Pennsylvania.

The life cycle of the fluke takes it through freshwater snails and back into water, where it is ingested by the larval stages of several aquatic insects, including caddis flies and mayflies.

The entire natural history and life cycle of N. risticii has yet to be elucidated, but bats and birds may be wild reservoirs of infection.

Signs and symptoms of PHF include acute-onset fever, depression (sometimes profound), inappetence, mild colic-like symptoms, decreased manure production, profuse watery non-fetid diarrhea endotoxemia, edema due to protein imbalances, abortion by pregnant mares, and acute laminitis (20 to 40 percent of cases).

This may include intravenous fluids and electrolytes to counteract the diarrhea;[1] NSAIDs such as Banamine (flunixin meglumine); intravenous dimethyl sulfoxide; administration of products such as Biosponge or activated charcoal via nasogastric tube to bind endotoxins; polymyxin B or plasma for endotoxemia; supportive shoeing; low doses of intramuscular acepromazine; and pentoxifylline.