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Thursday, July 30, 2015

"Swamp Cancer" is also called Equine Pythiosis.

It's also called "Florida Leeches."

Maybe some of you already knew about this and don't need the info here. Me, I only found out about it today. So, for all of you that don't know about it, here is what I have found out.

Fungal-like infection causing cutaneous or subcutaneous, gastrointestinal, respiratory or multisystemic disease in many species of animals including humans. Horses are most commonly infected.

The extremely rapid rate of growth of these lesions and the generally fatal outcome in these cases makes remembering this disease crucial for equine practitioners since early recognition and appropriate treatment are the only hope for survival for infected horses.

Florida is responsible for 60 percent of recorded infections. "Ninety-nine percent of the cases in horses are dermal infections that start with a break in the skin."

Typically begins as a small irritated area usually on the distal limb of a horse. This may be initially thought to be a sting, bite or small puncture, and the mild-looking lesion usually is not a cause of concern. Owners will generally begin cleaning the area and treating it with various topical antibiotic or anti-inflammatory creams. But within a few days, the lesion is markedly larger, red and irritated. It may also begin to be pruritic with the horse rubbing or even biting at the lesion. Veterinary attention is sought at this point.

Antibiotic and anti-inflammatory therapy is initiated at this stage, but the lesion continues to grow. It is tumor-like now, and serum freely leaks from the raw, irritated surface. Aggregates of necrotic cells form in the lesion, producing yellow to grey, pea-sized, gritty, coral-like bodies called kunkers. Although these structures are not specific to pythiosis, their presence is evidence enough to make one highly suspicious of fungal infection.

The lesion will continue to grow and eventually erode ligaments, tendons and bone and lead to death in 95 percent of cases within six months. This rapid tissue destruction is solely the result of a massive allergic response to the presence of fungal hypheal elements on the part of the horse. T2 helper cells drive this reaction, and mast cells and eosinophils dominate the cellular population. Some horses (about 5 percent) are able to switch to a T1 helper cell response that effectively kills the organism and switches to a lymphocyte and monocyte population that promotes healing.

Pan American Veterinary Labs has developed an enzyme-linked immunosorbent assay (ELISA) that is specific for the presence of pythiosis fungal elements and has greatly helped in the recognition of these cases. A simple blood sample is evaluated, and the disease can be confirmed. This testing can also recognize the presence of Lagenidium (three cases in horses have been confirmed so far.

"We have developed a 'vaccine' to pythiosis that can be used in confirmed cases, and this immunotherapeutic product works by helping the horse modulate the change from T2 helper to T1 helper cell response.

This product has been shown to have an almost 100 percent cure rate for acute cases (< 15 days) but is less effective in chronic cases (> 60 days). The overall rate of cure is 75 percent for all cases, strongly suggesting that early diagnosis and treatment are crucial to success.

Information from:
Kenneth Macella, DVM (Canton, GA)

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