Co-occurring factors in dog bite related fatalities

The Journal of the American Veterinary Medical Association analyzed dog bite-related fatalities from 2000 to 2009, and identified a co-occurrence of seven controllable factors (spoiler alert - breed was not one of them!). Four or more of these factors were present in over 80% of cases.

Factor #1 – lack of supervision. In over 87% of the cases, there was not an able-bodied person present to intervene. The most preventable incidents involved very young children left alone with dogs to whom they were unfamiliar, or toddlers allowed to wander off and encounter unfamiliar dogs. Young children should never be left unsupervised with any dog. A dog bite incident resulting from the lack of supervision can even be considered criminally negligent.

Factor #2 – lack of familiar relationship between the victim and the dog. Regardless of any established positive relationships a dog may have, it is incorrect to assume that the dog will feel comfortable around all people in all circumstances. An unfamiliar child or adult may change a dog's environment and perhaps its comfort level. It is important to educate yourself and children how to approach (or not approach) unfamiliar dogs, and to read basic canine body language.

Factor #3 – failure to spay/neuter. In over 84% of dog bite-related fatalities, the dog was sexually intact. Studies have shown that castration decreases dog aggression towards other dogs. Although it is unknown whether castration directly affects the incidence of aggression toward people, it is suggested that testosterone acts as a behaviour modulator, and thus sexually intact male dogs react more intensely, more quickly, and for a longer period of time. Intact dogs are also more likely to roam. 

We condone spay and neuter subsidy and outreach programs, like BAD RAP’s “Nut Truck” initiative. Mandatory spay/neuter laws have not been shown to be effective. 

Factor #4 – victim had a compromised ability to manage interaction with the dog(s). In over 77% of cases, the victim was in a particularly vulnerable state in relation to the dog. This could mean that the victim was a child or had limited mental or physical capacity. Nearly half of victims in the studied cases were under the age of five. 

Given the disproportionate number of dog bites occurring among children, it’s critical that children and parents are given tools to safely manage interactions. 

In some municipalities, organizations or parent groups have introduced bite-free education into school curricula or summer programs. Check out stopthe77.com for information and sample workshops. Justice for Bullies is thrilled that we are able to offer free dog bite prevention in several areas of Canada and Colorado.

Factor #5 - dog was kept as a resident, not family dog. In 76% of cases, dogs were kept as resident dogs rather than as family pets. A resident dog is defined as one that is isolated from regular, positive human interactions. When not afforded the opportunity for these interactions, a dog may be more likely to behave defensively in situations they perceive as stressful or threatening. 


Dogs are predisposed to form attachments with people and we have an obligation to provide for their psychological and social needs as well as their physical ones. Effective animal control laws will regulate elements like chaining, tethering, isolation, and general welfare, recognizing that by addressing these risk factors, we may eliminate aggressive behaviour down the road. Outreach programs like Beyond Fences can also play a role by working collaboratively with owners to improve the quality of life of dogs in their community.

Factor #6 – owner mismanagement. In 37% of cases, the owner allowed the dog to be a danger to others. For example, the owner may have been aware that the dog had an aggression history and failed to take proper precautions, or the owner repeatedly allowed the dog to run at large. It was also found that cases with mismanagement were more likely to involve multiple dogs and result in criminal charges for misdemeanours or felonies (in addition to animal control violations). 

This is why legislation and programs targeting responsible ownership are the only effective ways to keep communities safer. If a dog has potential to be aggressive, the warning signs must be identified as early as possible and proper training, management, and containment are essential. If this responsibility isn’t taken seriously, the owner must be held accountable with the end result being criminal charges and/or removal of the dog if necessary.

Factor #7 – neglect or abuse. The final factor should not come as any surprise. In over 21% of the cases, the dogs involved were subject to neglect or abuse. A history of neglect by the owner included instances of dogs not given access to basic needs (food, water, shade or shelter) and dogs with untreated medical conditions. Other more extreme cases classified as abuse included severe starvation, physical and sexual abuse, or dog fighting. When neglected or abused dogs are faced with stressful, potentially dangerous situations, they may behave in ways primarily to protect themselves.  

Of course, as we all know, a history of abuse or neglect does not automatically lead to aggressive behaviours. Any canine professional will tell you that dogs can be incredibly resilient and a great underlying temperament can overcome some of the worst abuse cases we see. As with humans, behaviour is a combination of nature and nurture. 

In BC and in many parts of Canada, the SPCA has jurisdiction over cruelty complaints. In these areas, call the SPCA Cruelty Investigation Department for any suspected cases of abuse or neglect. Your local animal control department may also be a resource depending on your municipal bylaws and the department’s service priorities.  

 https://avmajournals.avma.org/doi/abs/10.2460/javma.243.12.1726

https://www.nationalcanineresearchcouncil.com/sites/default/files/Dog-Bites-Problems-and-Solutions-2nd-Edition.pdf