Horse Rain Rot: Skin Welfare in Wet Conditions

Rain rot (dermatophilosis) is a bacterial skin infection common in horses kept in wet conditions, causing painful crusting lesions that impair coat health and comfort.

Key Facts

Rain rot is caused by Dermatophilus congolensis, an actinobacterium that thrives in wet, humid conditions.
The bacteria penetrate damaged skin, causing characteristic crusty scabs with matted hair underneath.
Lesions typically appear along the back, rump, and face — areas most exposed to rain.
When scabs are removed, they reveal moist, pink, inflamed skin that is painful to the touch.
Horses with long coats, compromised immune systems, or inadequate shelter are most susceptible.
Secondary fly strike and bacterial infections can complicate healing.
Treatment involves removing scabs with antiseptic washes and improving environmental conditions.
Chronic or severe cases may require systemic antibiotics.

Welfare Considerations

Rain rot causes significant discomfort — affected skin is painful when touched, making grooming and saddling distressing for horses. Chronic or untreated cases can cover large body surface areas, causing persistent pain and potential systemic illness. The condition is almost entirely preventable through good management: adequate shelter, dry bedding, regular grooming, and prompt treatment of minor skin injuries. Horses kept in chronically wet paddocks without shelter are at high risk, and this represents a husbandry failure rather than an inevitable disease outcome. Handlers must be trained to recognise early signs and treat gently, as rough scab removal without softening is painful.

What You Can Do

Provide adequate weatherproof shelter so horses can escape prolonged wet conditions.
Groom regularly and inspect skin under the coat, especially after wet weather.
Soften crusts with dilute chlorhexidine or betadine wash before gently removing scabs.
Keep bedding dry and repair any wounds promptly to prevent skin barrier breakdown.
Consult your vet if rain rot is extensive, recurring, or not responding to basic treatment.
Review paddock drainage and shelter provision as a management priority during wet seasons.