Domestic Dogs and Unintended Impacts on Wildlife

Taking a weekend hike with your dog is a beloved pastime for nature lovers. However, some parks or preserves may not allow dogs, while others may only permit them if on-leash. Such rules exist as part of park management goals to minimize ecological disturbance and also, because biologists are increasingly documenting the negative effects of dogs on wildlife.  Quantifying these potentially negative impacts of dogs on pumas and their prey is a focus of research currently underway by the Felidae team. 

To date, some of the impacts of dogs may include displacement of wildlife and wild animals may show increased stress in response to dogs. Also, unvaccinated dogs might transmit diseases to wildlife populations (wildlife may also transmit diseases to domestic dogs). This can be especially dangerous for threatened wildlife species. Indeed, domestic dogs have contributed to 11 extinctions so far. Off-leash dogs in particular can and do often directly kill native wildlife, further straining populations. It’s essential that dogs are managed responsibly in ways that support their well-being and that of wildlife to reduce harm going forward.  

Dogs can alter wild animals' spatial and temporal activity patterns. The sight, sound, and smell of dogs can be alarming to wildlife, resulting in them becoming displaced from areas either temporarily or permanently. Habitat loss due to the expansion of human footprint is already one of the most significant threats to biodiversity, so reduced access to land could be devastating. Some species could shift their daily activity to sub-optimal times of day as part of strategies to avoid interactions with dogs. Bobcats, for example, are detected less often in areas with domestic dogs and might change their temporal range to avoid dogs. 

The presence of dogs could also cause stress to wildlife which, over time, could increase an animal’s energetic needs and suppress its immune system, making it more vulnerable to sickness and disease. This added stress and increased limitations on range hurts an organism’s ability to survive and reproduce, making it harder for populations to persist. 

The increased susceptibility to disease associated with stress is worsened by the fact that dogs can transmit diseases to wildlife. Many dog owners hesitate to vaccinate their dogs, with 53% of owners believing that dog vaccines are unsafe, ineffective, and/or unnecessary, according to a 2023 study (n=2200). Unvaccinated dogs spread rabies, distemper, and parvovirus to wild animals. Dogs also spread diseases like giardia and toxoplasmosis. There are currently no vaccines for these diseases which may be spread through dog feces.

On the other hand, dogs may eat feces of wildlife or a dead or sick animal, which puts them in danger of infection. An unvaccinated dog may be infected with rabies from another sick animal, eventually becoming sick and dangerous before finally dying. Thankfully, many of these diseases can be prevented in dogs through maintained herd immunity. This occurs when the spread of a disease is reduced (due to, for example, high vaccination rates), thereby, reducing the chance of disease transmission to wild animals. Rabies, distemper, and parvovirus all can be vaccinated against, and many municipalities require dogs to be rabies vaccinated. Monitoring your pet and preventing their consumption of dead animals or feces, as well as picking up their own feces, will further limit the spread of disease.

Education about why dog-related rules in parks and open spaces exist is an important part of efforts to protect wildlife. This includes, for example, increasing awareness about why it’s important for hikers and their dogs to stick to designated hiking trails. Wildlife may prefer to avoid domestic dogs, so by concentrating human and dog presence on trails, they can better predict where disturbances are most likely, reducing the probability of unexpected and negative interactions between humans, wildlife, and dogs. 

When heading out to enjoy a day in nature with your dog, make sure to read up on the rules of the specific park or preserve you’re visiting to find out whether they allow dogs or not, and follow any posted safety guidelines for your pet. Always leash your dog when directed to by official guidelines. Be sure to vaccinate your dog and always pick up after your dog. By doing this, you will contribute to human-wildlife coexistence, keeping wildlife and your pets safe. 

References

Doherty, T.S., Dickman, C.R., Glen, A.S., Newsome, T.M., Nimmo, D.G., Ritchie, E.G., Vanak, A.T. and Wirsing, A.J., (2017). The global impacts of domestic dogs on threatened vertebrates. Biological Conservation, 210: 56-59.

George, S.L. and Crooks, K.R., (2006). Recreation and large mammal activity in an urban nature reserve. Biological Conservation, 133: 107-117. 

Greenfield, P., and Weston, P. (2021, October 14). The five biggest threats to our natural world ... and how we can stop them. The Guardian. 

Hennings, L., and Parks, M. (2016). The impacts of dogs on wildlife and water quality: A literature review. Metro Parks and Nature. 

Lenth, B.E., Knight, R.L. and Brennan, M.E., (2008). The effects of dogs on wildlife communities. Natural Areas Journal, 28: 218-227.

Motta, M., Motta, G. and Stecula, D., (2023). Sick as a dog? The prevalence, politicization, and health policy consequences of canine vaccine hesitancy (CVH). Vaccine, 41: 5946-5950.

Weston, M. A., and Stankowich, T. (2014). Dogs as agents of disturbance. Free-Ranging Dogs and Wildlife Conservation. Oxford University Press: Oxford, UK, 94-116.