Abstract

Occasionally captive nondomestic carnivores exhibit undesirable behaviors that may range from aggression to self-mutilation. These behaviors have been mitigated by a variety of methods including the addition of new enrichment items to their environment, or the use of anxiolytic agents.^1-3 The use of buspirone in three species of carnivores: a raccoon (Procyon lotor), a badger (Taxidea taxus), and an African lion (Panthera leo), lessened or solved the behavioral problems exhibited by these animals without noticeable side effects.

Case 1

A neutered 5-year-old male raccoon weighing approximately 9.5 kg developed a habit of barbering the fur of the rear third of its body, its tail, as well as barbering the hair of its brother’s coat. While this behavior did not pose any health problems, it did result in an abnormal appearance to these exhibit animals. Initially the raccoon was given additional enrichment items with treats routinely hidden within the exhibit in an effort to break their barbering habit. Bitter apple chew deterrent was placed on the fur of both animals and had no effect on the barbering. When these methods proved unsuccessful the raccoon was treated with buspirone (buspirone hydrochloride, Par Pharmaceutical Inc., Spring Valley, NY, USA) 0.26 mg/kg PO BID to manage the behavior. During the first month of treatment, the animal stopped barbering its sibling; however, it continued to barber the lower third of his body and tail, but at a reduced amount. After 1 month of treatment, the buspirone dose was increased to 0.53 mg/kg PO BID. It stopped barbering its body while on the higher dose, but continued to barber the tail, never allowing the hair to grow back. In an attempt to stop the tail barbering, the buspirone was discontinued and amitriptyline (AstraZeneca Pharmaceuticals, Wilmington, DE, USA) 10 mg PO SID was given for 23 days which appeared to cause the barbering of the tail to worsen with excoriations evident for the first time. The amitriptyline was discontinued, and no other drug regimens were started. The excoriations on the tail healed but the animal continues to barber the hair on its tail. The buspirone appeared to help to extinguish the barbering of the body hair and the hair of the other raccoon; however, it did not completely extinguish the behavior of tail barbering in this animal.

Case 2

A spayed female badger weighing approximately 11 kg had a lifelong history of apparent anxiety attacks which generally were manifested by loud screaming and obvious agitation. Over the years the worst episodes of this behavior resulted in the animal biting at sides of its body causing excoriations to the skin. Diazepam (Valium, Roche Pharmaceuticals, Nutley, NJ, USA; 0.7 mg/kg PO SID) was given to manage the more severe episodes. The lesser episodes had been controlled fairly well with the addition of enrichment to the animal’s exhibit. Over a 10-year period, the episodes grew worse in both intensity and duration. The typical side effects of the valium (inactivity and a tendency to sleep most of the day) were suboptimal for this exhibit animal. After a particularly severe set of episodes the diazepam appeared to have little effect and was discontinued in favor of a new anxiolytic drug, buspirone, which was given at a dose of 0.45 mg/kg PO BID. After 3 weeks of treatment the episodes of self-mutilation ceased, and the animal appeared content and playful most of the day. The buspirone appeared to effectively control the aberrant behavior in the badger, and the animal was maintained on the drug twice daily for over 18 months with no obvious side effects.

Case 3

A 17-year-old intact male lion weighing 183 kg housed with a female lion periodically exhibited very aggressive and possessive behavior towards its mate and its surroundings. This behavior occurred 2–3 times each year, with each episode lasting from 2 to 14 days. These events appeared to occur sporadically but were occasionally precipitated by large noisy crowds of people. The male often refused to eat or drink, and if on exhibit, would not allow his mate to eat, drink or leave the exhibit area. The male was treated with 0.11–0.33 mg/kg diazepam PO BID. whenever these aggressive episodes occurred. The diazepam did not provide a reliable steady behavioral state and the lion would either appear too aggressive or too groggy. The episodes could be controlled with just a few days of diazepam treatment if the problem was recognized in the morning and the lion was kept in the night quarters for treatment. However, if the lion was allowed into the exhibit during the time when one of the aggressive episodes occurred, it frequently refused to come into the holding area, refused to allow the female in, and sometimes could not be administered medication for many days. These periods could last for up to 2 weeks. The animal would be maintained on 0.11–0.33 mg/kg diazepam PO BID until it was no longer displaying possessive behavior as determined by the keepers when they arrived in the morning. Based on the animal’s behavior, the diazepam dose could be lowered or it could be discontinued. Because of the inconsistencies produced by the diazepam treatment, the treatment plan was changed to buspirone. The optimal dose of buspirone for this animal appears to be 0.16 mg/kg PO in the morning and 0.11 mg/kg PO in the evening. The lion has been maintained on this dose since May 2004. The lion exhibits all of its normal behaviors with no aggressive or possessive behavior seen. Because there have been no noticeable side effects to the buspirone, there is no plan to discontinue the drug at this time. Treatment of the male with buspirone has improved the quality of life for both the male and the female lion.

Literature Cited

1.  Baker, D. G. 2002. Combination therapy for footpad lesions in a captive Bengal tiger (Panthera tigris tigris). J. Zoo Wildl. Med. 33: 389–391.

2.  Gage, L.J. 2005. Use of buspirone to manage aberrant behavior in an American badger (Taxidea taxus). J. Zoo Wildl. Med. (In press).

3.  Hart, B. L., and L. L. Cooper. 1996. Integrating use of psychotropic drugs with environmental management and behavioral modification for treatment of problem behavior in animals. J. Am. Vet. Med. Assoc. 209: 1549–1551.