A: Rain rot (if you are referring to dermatophilosis, a bacterial infection) is a common condition seen in horses during rainfall periods (since moisture predisposes the disease). Up to 80% of a herd can be affected. Important things to remember about management are:
- Make sure you have the right diagnosis (other diseases can resemble rain rot)
- It is very important to keep the horses dry
- Most cases spontaneously regress within 4 weeks if the horses are kept dry
- Crust/scabs removal and disposal is also helpful; crust removal may be painful and may require sedation.
- Topical therapy can help. 2‐5% lime sulfur, 4% chlorhexidine solutions should be applied as total body shampoos or dips for about 5 consecutive days, then weekly until the scabs are healed. For the more localized lesions, use spray forms.
- Sometimes systemic therapy is needed (antibiotic such as penicillin or potentiated sulfas) mainly for severe, generalized, or chronic cases.
By Sandra Nogueira Koch, DVM, University of Minnesota