What is Equine Pythiosis?

Learn about pythiosis, a disease characterized by ulcerative, granulomatous lesions on and beneath horses’ skin.
Share
Favorite
Close

No account yet? Register

ADVERTISEMENT

The triad of warm temperatures, flooded lands, and aquatic vegetation highly favors the proliferation and maintenance of Pythium insidiosum, a pathogen of plants and, occasionally, mammals and birds. The disease, named pythiosis, has worldwide distribution in horses and has been known by different names according to geographical location: “bursatte” in India, “leeches” and “swamp cancer” in Australia and the United States, and “ferida da moda” in Brazil.

In horses, the agent causes ulcerative, granulomatous lesions mainly in the cutaneous and subcutaneous tissues. P. insidiosum also causes gastrointestinal, ocular, and disseminated forms of the disease in other animals.

In horses, skin lesions are more frequent in the limbs, chest and abdomen, parts which are in direct contact with water containing zoospores (the infective stage) of P. insidiosum. It is hypothesized that the zoospores are not able to penetrate the intact skin, but a small lesion such a mosquito bite is enough to allow entry. An association between lesion locations and areas of insect blood feeding has been demonstrated in horses.

While the pathogenesis of pythiosis is not fully understood, after an incubation time of 15 to 20 days, horses typically develop granulomatous, ulcerative lesions, marked by fistulas draining serosanguinous (blood and serous fluid) exudate. Lesions also contain firm and necrotic-gray material referred as “kunkers.” These kunkers contain viable hyphae (microscopic structures) that are important for differentiating the disease from equine sarcoid, squamous cell carcinoma, granulation tissue, and other lesions

Create a free account with TheHorse.com to view this content.

TheHorse.com is home to thousands of free articles about horse health care. In order to access some of our exclusive free content, you must be signed into TheHorse.com.

Start your free account today!

Already have an account?
and continue reading.

Share

Written by:

Related Articles

Stay on top of the most recent Horse Health news with

FREE weekly newsletters from TheHorse.com

Sponsored Content

Weekly Poll

sponsored by:

Where do you primarily feed your horse?
309 votes · 309 answers

Readers’ Most Popular

Sign In

Don’t have an account? Register for a FREE account here.

Need to update your account?

You need to be logged in to fill out this form

Create a free account with TheHorse.com!