Papers presented at the annual meeting of the American veterinary society of animal behavior, San Francisco, CA, July 11, 1994

The functional classifications of interdog aggression are as diverse as the types of aggression that dogs direct toward people. An effort should be made to determine the reason a dog exhibits aggression to another or at least to identify the stimulus complex that elicits the aggression. The latter is particularly important regarding daily management of the animal and if the clinician intends to implement a behavior modification program. Classical desensitization and counter-conditioning techniques can be used to treat aggression stemming from fear. Intermale aggression can often be reduced by castration and/or progestin therapy. Regardless of the motivation, the response of an aggressive dog on a leash towards other dogs can be counter-conditioned. The use of a “dog-head-halter” can be very helpful and a prudent safety precaution when implementing such a program. Managing aggressive behaviors of dogs within a household can be very difficult and not always practical or implementable. Sometimes these situations can be managed by identifying the stimulus complexes in which aggression occurs, and designing a behavior modification program that rewards one of both dogs for inhibiting themselves, e.g. remaining motionless, sitting or lying down. For example, both dogs might be taught to sit immediately when the owner enters the house; Dog A is rewarded for remaining quiet while the owner pets Dog B, etc. Even if the owner is able to control the aggressive behaviors of his/her dogs with such exercises, it should not be assumed that the dogs will be unaggressive in the owner’s absence. The person is part of the counterconditioning process and undoubtedly serves as a discriminating stimulus for whether or not the dogs engage in passive behaviors. It should never be assumed that dogs that are aggressive in the presence of the owner (especially if the aggression is severe) will be “all right” when the owner is not there. Dogs have been known to kill another dog when the owner has not been there to intervene. 0168-1591/95/$09.50