Risk factors for attacks by dogs on other dogs, cats

Dog attacks on other dogs or cats are traumatic events for pet owners—but what do we know about how commonly they occur, or how you might reduce the risk of your pet being involved?

A recent study by the University of Adelaide, in conjunction with the Animal Emergency Centers in Melbourne, demonstrated that in four separate emergency veterinary hospitals, 2.4% of all presentations were the result of dog attacks.

"As an emergency veterinarian, I see directly the emotional and financial cost when a pet is attacked by a dog," said lead author Dr. Christine Heyward, an Adelaide alumna working in Melbourne who carried out the research with the university.

"There have been many studies (around) dog bites on humans but this is one of the first studies to report the numbers of cases and investigate risk factors relating to being attacked by a dog."

Thankfully, almost 92% of dogs that presented with bite injuries survived the attacks and were later discharged and given a clean bill of health. Cats, however, were not so lucky: their survival rate through to discharge was less than half—at 46%.

"This is likely due to the smaller size of cats," said Dr. Susan Hazel, from the School of Animal & Veterinary Sciences at the University of Adelaide, adding that cats also tended to present with more severe injuries than dogs.

The emotional cost of such trauma is distressing to owners, but they often needed to dig into their pockets too. In most cases involving dogs and cats, the cost was between $360 and $380, but she said some longer hospital stays were likely to cost their owners thousands of dollars—and in one serious case, the bill ran to more than $13,000.

Risk factors for a dog presenting after a dog attack included being a cross-bred versus pure-bred dog and being neutered. However, dogs aged between two and seven were actually less likely to be attacked.

Dr. Heyward said: "It's hard to interpret why neutered dogs might be more likely to present. It's possible that non-neutered dogs sustained fewer injuries in fights—or were involved in less fights. Neutered dogs had a 76% survival rate when presenting versus only 39% for non-neutered dogs, so they were more likely to present but may have had less severe injuries."

Where the animals live also makes a difference: In lower socio-economic areas, dogs were more likely to be attacked at home by a known attacker; in areas with a higher socio-economic score, dogs were more likely to be attacked in public by an unknown dog.

Dr. Hazel said it was interesting to compare these results to what we know about dog attacks on humans. She explained: "(For instance) in a recent study from the University of Queensland, pediatric dog bites were clustered in lower socio-economic areas south of Brisbane."

She said while most dogs were friendly and much-loved companions, people needed to be aware that dogs not only bite people but also other animals. If a dog is showing aggressive behavior, owners needed to exercise due care and responsibility—keeping them on a leash when outside the home, or safely contained . . . for example, inside or in a secure and fenced yard.

Dr. Hazel added: "If your animal is attacked by a dog, that attack should be reported as soon as possible to your local council, which will then investigate.

"Through research into dog attacks it is hoped we can design programs to reduce the risk of dog bites—this will be a win-win for both animal and human welfare."