OVC study highlights geographic, seasonal and pet risk factors for encountering ticks

Each spring, companion animal owners are reporting tick sightings and bites on their dogs and cats earlier than ever in online forums and to their veterinarians. Climate change means that ticks are not only emerging earlier each year, but their geographic ranges are changing. 

The increase in tick exposure has led to a rise in tick-borne pathogens like Borrelia burgdorferi, the contributing cause of Lyme Disease, which has become the most reported tick-borne disease in North America among humans and dogs.  

A recent study from the Ontario Veterinary College (OVC), funded by OVC Pet Trust, sought to understand where and when certain species of ticks are active across Canada and then worked with veterinarians and pet owners to track tick bites to better understand patterns that could make it easier for pet owners to find and remove ticks on their pets. 

Sydney DeWinter, a current doctoral student of epidemiology in OVC’s Department of Population Medicine, led the study as part of her master’s thesis under the guidance of Dr. Katie Clow.  

“Through the study, we learned the time of year and places where major species of ticks like the blacklegged tick and the American dog tick are most active,” says DeWinter. “But we also gained an understanding of the specific infestation patterns these species show to inform where a veterinarian or pet owner might look for them during a tick check.” 

The best places to look for all ticks on dogs will be their heads, neck and shoulders. For cats, it’s best to look for ticks on their head and neck area. Pet owners will want to target these spots after walking in wooded or brushy areas or areas with long grass when temperatures are above freezing. “The hope is that knowing these patterns and checking pets at the right time of year and in the right places will help pet owners find and remove ticks faster, preventing disease,” adds DeWinter. 

The study relied on pet owners reporting ticks on their animals and submitting samples to be studied alongside information about the location in Canada where the tick came from, where it was located on the pet and what date it was removed.  

“We learned from the study that blacklegged ticks in particular are becoming prevalent in the central and eastern provinces and show at least some activity all year long,” DeWinter says. “In Ontario and Quebec, blacklegged ticks were submitted most often between April to July, with peak activity in May. These ticks declined in the hotter months of June, July and August, with a peak again in September to November.” 

The study also uncovered that herding, sporting, terrier, toy and work breed groups have higher odds of attracting blacklegged ticks compared to dogs of non-sporting breeds. 

“It’s pretty typical for those types of dog breeds to live an active, outdoor lifestyle,” says DeWinter. “Breeds within those groups, like cattle dogs, collies and retrievers, are commonly bred for outdoor work and recreation that make them more inclined to encounter ticks while using the same spaces.” Dogs in the toy group have likely been captured in this study as high risk due to their shorter stature when roaming through long grass. 

For cats, the risk factors showed a different pattern. Of the 2,306 tick submissions that DeWinter received, 17 percent were from cats, which indicates ticks are as important an issue for cats as they are dogs. Young cats were found to have lower chances of tick bites, likely because of the differences in exposure than dogs. Whereas puppies frequent the same habitat spaces as ticks early in their life, cats under a year old are likely kept home due to health and safety risks in their first year of life. 

“The key takeaways for this study for veterinarians and pet owners should be that, as climate change lengthens the tick season, checking dogs and cats for ticks should happen frequently,” DeWinter suggests. “Continue to have conversations with primary care veterinarians about tick prevention, particularly around the peak months that ticks are active in your area.”