Understanding “Swamp Cancer” in Horses & Dogs

“Swamp Cancer” is a colloquial or informal name sometimes used to describe a fungal-like oomycete condition (Pythiosis) that affects horses, dogs, and occasionally other animals.

(Also known in veterinary literature as a chronic yeast- or mould-associated skin condition)

“Swamp Cancer” is an informal term used in some regions to describe a severe skin and tissue condition that develops when animals come into contact with certain water-based organisms such as moulds, yeasts, or fungal-like organisms found in damp, swampy, or stagnant environments.

While the name varies, and the exact organism can differ between cases, the common feature is environmental exposure to wet, muddy, or marshy areas where these organisms thrive.

How the Condition Develops 

Animals—particularly horses and dogs—may be at higher risk if they:

• Spend long periods in wet pastures, swamps, or stagnant waterways

• Have scratches, wounds, or irritated skin that allow environmental organisms to enter

• Live in tropical or subtropical climates where environmental moulds and yeasts flourish

• Experience prolonged moisture on the skin or legs

These conditions may create an environment where fungal-like or yeast organisms can multiply and affect the surrounding tissues.

Common Signs Discussed in Veterinary Literature 

Reports often describe:

• Thickened or granulating areas of skin

• Moist, irritated lesions

• Unusual nodules or wart-like tissue

• Foul-smelling or yellowish discharge in chronic cases

• Areas that do not heal well despite cleaning

• Progressive irritation if the animal remains in the same environment

These descriptions are provided for awareness and should not be used for diagnosis.
Veterinary consultation is essential.

Environmental Factors Often Mentioned

The condition is often associated with:

• Wet, swampy environments

• Standing water or mud

• Rotting vegetation

• Warm climates with high humidity

• Areas with known aquatic mould or yeast organisms

Supporting the animal by reducing exposure to wet environments may assist overall wellbeing.

Why It Affects Horses and Dogs

Both species frequently:

• Walk through or stand in wet ground

• Develop small skin openings from scratches, burrs, insects

• Have prolonged contact with mud on legs or paws

• Experience immune or skin stress from environmental factors

Certain breeds with sensitive skin, long coats, or feathering may also be more prone to irritation in swampy conditions.

Holistic or Natural Perspectives 

In natural health systems, traditional supportive measures often focus on:

• Maintaining skin integrity

• Supporting immune balance

• Encouraging tissue comfort

• Helping the body manage environmental microbial stressors

• Promoting general resilience and recovery capacity

These supportive approaches are complementary and do not replace professional veterinary care.

* Natural pet botanicals are not intended to replace veterinary care or medication. 

SET OF

Need more advice or have more questions? Contact us for a FREE consultation with one of our fully qualified practitioners.   

These statements are for general wellbeing and educational purposes only. This product is not intended to diagnose, treat, or prevent any disease. Always seek veterinary or professional advice for specific health concerns.

DISCLAIMER
The statements made regarding these products have not been evaluated by the Food and Drug Administration. The efficacy of these products has not been confirmed by FDA-approved research. These products are not intended to diagnose, treat, cure or prevent any disease. All information presented here is not meant as a substitute for or alternative to information from your health care practitioners. The Federal Food, Drug, and Cosmetic Act require this notice.