Swamp cancer is a relatively uncommon form of infection in dogs, horses, cats and humans. It is caused by a fungal infection known as phycomycosis due to pathogens that are present in stagnant water molds and fungi. The most common form of the disease is pythiosis that invades the body by contact and/or consumption of infected water. Although more common in dogs and horses, it can potentially occur in cats, cattle and even humans.
The most likely cause is the invasion of Pythium insidiosum. The organism needs stagnant water to reproduce and thrive. It can affect dogs swimming in swampy water or drinking contaminated water and also those coming in contact with grass that has been exposed to stagnant water. The organism, present in water molds, enters into wounds in the skin or the gastrointestinal tract. Gradually the disease grows in the stomach and small intestines and leads to symptoms similar to the symptoms of liver cancer in dogs and gastrointestinal cancer. Some of these symptoms are listed below:
- Loss in weight
- A lump of mass in the abdomen
Pythiosis of the skin leads to ulcerated lumps, but it is rare in dogs. Granulomatous and itchy lesions containing yellow, firm masses of dead tissue form on the lower limbs, abdomen, chest and genitals. In instances of severe prevalence, the disease may spread to the underlying bone. As a form of feline cancer, swamp cancer usually affects only the skin in cats and appears mostly in the limbs, perineum, and the base of the tail and rarely in the nasopharynx.
Even though an ELISA (enzyme-linked-immunosorbent serologic assay) test has been developed for animals, a definitive diagnosis is done through biopsy. Prognosis for swamp cancer in dogs is poor. Surgery is not possible in all cases, and even when surgery is performed, there is an inherent risk of postoperative recurrence. Antifungal drugs have a limited affect on the disease and a new drug meant for water molds is extremely expensive.
Regardless of the fact that water is utmost necessary for the survival, we have paid little regard to this natural source of life. As long as the water around us is polluted, the only prevention that we can take for our pets is to keep them away from potentially infected water. It is also recommended that dogs should not be allowed to drink from puddles and ponds. Even if this care can be taken, dogs still face a risk from contaminated grass that has come in contact with contaminated water.
It is improbable that we will be able to keep hunter dogs away from swamps and stagnant waters. Unless we take efforts to make our planet greener and avoid polluting the atmosphere and water, it seems that we may have to be careful of the contamination that exists.