Tranquillization of cane rats (Thryonomys swinderianus) with a depot neuroleptic (pipothiazine palmitate)

Stress-induced self-trauma is a major cause of mortality among captive cane rats (Thryonomys swinderianus). Six subadult female cane rats were injected with a long-acting neuroleptic drug (pipothiazine palmitate 25 mg/kg), and an equal number were injected with isotonic saline. Their behaviour and reactions to stimuli were recorded daily. After 5 weeks, treated animals continued to display significantly less stress-related behaviour than the control group. In addition, two abbreviated studies were conducted. Eleven subadult males were treated identically to the females. Their behaviour was recorded for 1 week. Subsequently, 11 indocile animals on a commercial cane rat farm were tested for calmness, treated with pipothiazine and retested after 2.5 weeks. The results of these studies were similar to those in the female study. A significant taming effect was seen 30 days after a single treatment for all invasive or aggressive tests in treated cane rats, and no extrapyramidal effects were noted. Pipothiazine affected neither their alertness nor weight gain. However, substantial behavioural alteration requires the exposure of the animal to stressful stimuli during the treatment period. Pipothiazine palmitate decreases the stress experienced by cane rats, eases their transition to a new environment, makes them easier to handle and less likely to injure themselves.