Learn about rain scald, a common skin disease in horses caused by excess moisture. Discover prevention and treatment methods to keep your horse healthy over winter.
Rain scald and mud rash are just some of the problems plaguing horses over the winter months. As the weather begins to change, we are faced with different seasonal skin diseases in our horses and ponies. Here, we take a look at rain scald, where and when it’s likely to strike, prevention, and treatment.
What is Rain Scald?
Rain scald (or Rain Rot) is superficial dermatitis in horses caused by the bacterium Dermatophilus Congolensis.
This bacterium is a normal skin resident, but excess moisture and humidity cause the ’spores’ to disperse and penetrate the skin, and infection occurs. It is most commonly found along the horse’s back, neck, and head.
The clinical symptoms of the disease are clumps of matted hair with an ovoid-shaped scab underneath. The undersurface of the scab often has hair roots protruding through, giving the appearance of a ‘paint brush’.
Horses are not often itchy with rain scald, but the scabs can be painful to remove as the skin is painful and oozes serum. Severe cases may mean you are unable to ride your horse due to the painful lesions under the saddle area.
Confirming Diagnosis of Rain Scald
The diagnosis of rain scald can usually be confirmed by clinical symptoms, however, your vet may take a hair sample, skin scrape, or swab to certify the disease.
Prevention of Rain Scald
Good management can easily prevent the condition. Horses should be kept dry with appropriate rugging and stabling in the wet weather.
The condition can be contagious between horses by sharing of grooming brushes; clippers, numnahs, and other equipment, so take sensible precautions regarding biosecurity measures.
If your horse gets caught in a downpour, make sure you thoroughly dry him before placing any rug on.
If your horse gets caught in a downpour, make sure you thoroughly dry him before placing any rug on
Treatment of Rain Scald
Spontaneous recovery can occur between 3-6 weeks, provided appropriate control and group eradication measures are in place. Horses receiving topical treatment will heal faster.
The bacteria are susceptible to chlorhexidine and povidone-iodine washes, and these washes should be used to help remove the scabs and treat the underlying skin lesions.
Topical antibacterial creams can be helpful, and in severe cases, systemic antibiotics may be warranted. Washing grooming brushes in disinfectant and avoiding sharing tack and equipment with other horses will help prevent the spread of the disease.
Horses do not develop immunity to this condition. If your horse has had it once, it may suffer again in wet conditions in the future.
It is best to consult your vet if you think your horse may have rain scald so they can advise on the most appropriate treatment
Reasons for Treatment Failure
The key is to treat all affected horses. If a chronic carrier is not treated appropriately then they may be a source of infection to other horses.
Repeated exposure to the wet weather will significantly decrease the success of treatment. As well as topical treatment it is vital that appropriate rugging and shelter is provided.
Special care should be taken for the elderly, immuno-suppressed horses, or those diagnosed with Cushing’s disease.
If there is an underlying disease process, your horse may not respond as anticipated to treatment, and advice from your vet should be sought.
Written by Nancy Homewood BVetMed MRCVS.
Suzanne Ashton, Founder of Everything Horse (Est, 2012), has a BA Hons in Marketing Management and a Diploma in Equine Science. Suzanne has ridden and owned horses all her life and has twelve years of experience in marketing, writing, design, SEO, and website creation.