Use of low-dose chlorpromazine in conjunction with environmental enrichment to eliminate self-injurious behavior in a rhesus macaque (Macaca mulatta).

A 7-year-old, captive-bred, female rhesus macaque was placed in a quarantine facility upon arrival at our institution. At release from quarantine, she was observed pawing at and chewing on her left cheek. Physical examination revealed ulcerative lesions on the buccal surface of the left cheek. Initial differential diagnoses included Cercopithecine herpesvirus 1 (B virus)-induced lesions and bacterial infection. Dental abnormalities and cheek pouch foreign body were ruled out during the physical exam. Treatment with 30 mg/kg cefazolin intramuscularly every 12 h was initiated. Twelve days later, the animal presented with a 2 x 2-cm, full-thickness erosion involving the opposite (right) cheek. Treatment with buprenorphine (0.1 mg/kg intramuscularly every 24 h) was initiated. Cultures for B virus were negative, and only nonpathogenic bacteria were isolated from swabs of the lesions. Hematology and serum chemistry profiles were normal. A wedge biopsy of the lesion revealed no definitive etiology. Further observation revealed that the lesions likely resulted from self-injurious behavior (SIB). Treatment with low-dose chlorpromazine (1 mg/kg intramuscularly once daily for 25 days, and then 0.5 mg/kg intramuscularly once daily for 25 days) was initiated. Bodyweight and condition were maintained during therapy, and serial hematology and serum chemistry profiles were normal. The animal was moved into a different room, and a toy "necklace" was created. The SIB was eliminated, and lesions healed within 35 days. Presently, 20 months after presentation, this animal remains in good health.