WEDNESDAY, Oct. 3, 2007 (HealthDay News) -- Underlying anxiety, pain and other behavioral or medical problems can help prompt dogs to bite children, a new study suggests.
Researchers at the University of Pennsylvania looked at 111 cases involving 103 dogs that bit children and were referred to a veterinary behavior clinic over four years.
"Guarding of resources and territory" were the most common triggers for aggression by these dogs, according to the study in the journal Injury Prevention.
One in five of the dogs had never bitten a person before, and two-thirds of them had never bitten a child before.
The study found that young children were much more likely to be bitten when a dog felt their food or other items, such as a toy, were under threat. In cases involving older children, the bite was more likely the result of a dog's territorial behavior.
Food guarding was the most common cause of bites involving children familiar to the dog, while territorial guarding was the most likely cause in cases involving unfamiliar children.
The study also found that three-quarters of the dogs exhibited anxiety when left by their owners or when exposed to loud noises such as fireworks or thunderstorms. The authors said demonstrable fear in dogs may signal a tendency to bite when the dogs are confronted with a perceived threat.
The researchers noted that young children can be noisy and unpredictable in their movements, both of which may frighten an already anxious dog.
Half of the dogs in the study had medical conditions, mostly affecting their skin or bones. Other health issues included growths, eye problems, liver and kidney disease, hormonal problems and infections. Pain may have been a factor in some of the dog bite cases, the authors said.
The U.S. Centers for Disease Control and Prevention offers advice on how to prevent dog bites.