Which term refers to a skin disease caused by bacteria in horses?

Rain rot, also known as greasy heel or dermatophilosis, is a skin disease caused by the bacterium Dermatophilus congolensis. It primarily affects horses, especially in wet or humid conditions. The condition manifests as crusty scabs and hair loss, often occurring in patches on the skin. The bacteria thrive in moist environments, making horses that are frequently exposed to wet conditions more susceptible to this ailment.

Understanding the context is important when considering why other options do not fit. Thrush is a hoof condition related to bacterial infection but affects the feet rather than the skin. Kissing spine refers to a spinal condition in horses and does not relate to a skin disease. Colic pertains to gastrointestinal distress and has no connection to bacterial skin infections. Thus, rain rot is the only term that directly describes a skin disease caused by bacteria in horses.