An overview of types of aggressive behaviour in dogs and methods of treatment

Blackshaw, J.K., 1991. An overview of types of aggressive behaviour in dogs and methods of treatment. AppL Anim. Behav. Sci., 30: 351-361. In 223 cases of dogs presented to a specialist behavioural clinic in Brisbane, Australia, 87 (39%) were for severe aggression. The classes of aggression included dominance (31.6%), territorial (29%), predatory ( 12.3% ), intermale ( 12.3% ), sibling rivalry ( 7.9% ), fear biting ( 6% ) and idiopathic rage (0.9%). The breeds most represented which attacked humans were the Bull Terrier (16%), German Shepherd and crosses ( 15% ), Cattle dog breeds (Blue Heeler and crosses, 9.2% ), Terrier breeds ( 9.2% ), Labrador (8%), Poodle and Cocker Spaniel (both 5.7%) and Rottweiler (4.6%). The dangerous dog list put out by the local Brisbane City Council includes the first three breeds mentioned and the Rottweiler as the top four breeds causing aggression problems. Hospital records in Victoria and Queensland confirm that most damage is caused to humans by Bull Terriers and German Shepherds. Many breeds similar to those in our study are also represented in American data on aggressive breeds. Treatments included obedience training only, restraint only, obedience and restraint, synthetic progestins and obedience, castration, progestins and obedience, castration and obedience, use of chlorpromazine and as a last resort, euthanasia (12.6%). Entire males formed the largest group (44%), followed by castrated males and females (both 21%) and spayed females (15%). Several breeds (Boxer, Briand, Samoyed and St. Bernard) only attacked other animals and birds. This study reinforces evidence that social disruption is caused by aggressive dogs, but it also indicates that many responsible clients seek advice on how to deal with this behavioural problem. I N T R O D U C T I O N The most common behavioural problem in dogs referred to the University's Companion Animal Practice during a 6-month period was aggression towards family members and other animals (Blackshaw, 1988 ). There are various types of aggression, including competitive, sexual (intermale), territorial, predatory, pain-induced, fear-induced, maternal, learned and dominance aggression and these have been described by Houpt (1979), Hart (1980), Beaver (1983) and Blackshaw (1985). Idiopathic rage is not 0168-1591/91/$03.50 © 1991 Elsevier Science Publishers B.V. 3 5 2 J.K. BLACKSHAW common but has been described by Hart and Hart (1985) and Blackshaw (1987). In many cases the outcome is similar, an adult or child is savaged badly or another animal is killed. It is useful for a veterinarian or animal behaviourist to be informed about dog breed characteristics so that some of the problems associated with aggression can be avoided. Hart and Hart ( 1985 ) produced a table ofbehavioural profiles of dog breeds which can be used to aid selection of an appropriate dog. These workers classified dogs into very high, medium and very low aggression groups and this was associated with varying degrees of ease of trainability and reactivity (affection demand, excitability, excessive barking, snapping at children, general activity ). Blackshaw (1988) listed the German Shepherd, Bull Terrier, Labrador, Cocker Spaniel, Poodle, Cattle dog and various terriers as the most common aggressive dogs seen in the University clinic. Three of these breeds occur on the list of the four most aggressive breeds of dogs compiled by Brisbane City Council (released in the Courier Mail, Brisbane, Qld., 3 October 1989 ). These breeds were German Shepherds, Rottweilers, Bull Terriers and Cattle dogs. A recent study of the incidence of dog attacks on children requiring hospitalisation in Brisbane, Australia (Podberscek et al., 1990) indicated that where the breed was recorded, the Bull Terrier was the most commonly involved. Other breeds identified were the Kelpie, Dobermann, Dingo and another Terrier breed. Of recorded dog bites requiring attention in a Victorian Hospital (Australia), where the breed of dog was identified, 47% were caused by the German Shepherd. Other breeds were the Blue Heeler cattle dog (12%), Labrador (9%), Dobermann (6%) and the Terrier breeds (6%) (Thomas and Buntine, 1987). The number of cases of aggression recorded of various dog breeds must be considered in relation to the frequency of those breeds in the community. Studdert ( 1989 ) compiled a list of the purebred registrations in Australia for 1988 (91 768 dogs). The most common breed is the German Shepherd (12%), followed by Rottweiler (7.5%), Cattle dog (4.7%), Chihuahua (4%), Labrador (3.8%), Dobermann (3.4%), Cocker Spaniel ( 3.2% ), Bull Terrier ( 3.1% ), Boxer (3%), Poodle (2.9%), Border Collie, Golden Retriever and Staffordshire Bull Terrier (all 2.8%), Australian Silkie Terrier (2.3%), Collie varieties (2.2%), Maltese and Welsh Corgies (both 2.1%), Dachshund and Cavalier King Charles Spaniel (both 2%) and the Shetland sheepdog ( 1.4% ). The breeds whose owners sought advice for the dogs's aggression, the types of aggression, treatments prescribed and the outcomes of the treatment are discussed in this paper. The dogs treated are those referred by local and interstate veterinarians, the Royal Society for the Prevention of Cruelty to Animals (RSPCA) and the Brisbane City Council pounds. The Australian Postal AGGRESSIVE BEHAVIOUR IN DOGS 353 System and private solicitors also seek advice, and the services of an expert witness (Blackshaw) are used in some dog bite cases which come to court. ANIMALS, MATERIALS AND METHODS Over the last 2 years, advice has been given in 223 cases of behavioural problems of dogs, through the University of Queensland's Companion Animal Practice. Of these dogs, 87 (39%) were referred for severe aggression either to adults or children or to other animals (pets, wildlife, livestock) and birds. The ad{,ice on treatment for and management of the different types of aggression was given by the author, an animal behaviour consultant, and the Practice or referring veterinarians performed the clinical examinations and prescribed drugs. Where the dog was referred by a veterinarian, this person with the advice and assistance of the behavioural consultant managed the case. Follow up was either undertaken by the referring veterinarian or directly by the University's Animal Practice.