Self trauma and Staphylococcus aureus in ulcerative dermatitis of rats.

Eight cases of ulcerative dermatitis occurred in 7 groups of adult male Sprague-Dawley rats. Coagulase-positive Staphylococcus aureus was isolated from skin lesions of all affected rats; in some affected rats, coagulase-positive S aureus was also isolated from the feces and oropharynx. Amputation of toes of chronically affected rats resulted in remission of lesions. Self trauma (scratching with the hind feet) and fecal contamination of wounds with coagulase-positive S aureus were postulated as factors contributing to persistence of lesions in affected rats.