Tick season arrives early — what vets are seeing in 2026
It's not your imagination. Your vet is busier than usual this spring, and ticks are a big reason why. The CDC has issued a warning that 2026 may be the worst year for ticks in nearly a decade — and tick season started earlier and faster than usual. For pet owners, that means the familiar advice to "check your dog after walks" is no longer enough. The threat is bigger, broader, and arriving in places it hasn't been before. Here's what's actually happening — and what you should do about it.
thepetenvoy
5/8/20244 min read
The map has changed
For years, the mental shortcut for tick risk was geography: live in the Northeast, worry about Lyme. Live in the Southeast, watch for ehrlichiosis. That shortcut is now dangerously outdated.
The Companion Animal Parasite Council (CAPC), whose annual forecasts have historically been 94% accurate, warns that vector-borne disease risk continues to expand geographically across the US — with Lyme disease, ehrlichiosis, anaplasmosis, and heartworm now pushing into areas once considered low- or moderate-risk.
Blacklegged ticks — the primary carriers of Lyme disease — continue to expand geographically. While the Upper Midwest and Northeast remain the highest-risk regions, the 2026 forecast projects notable spread into Ohio, Kentucky, West Virginia, Tennessee, North Carolina, Indiana, Illinois, and Michigan, with westward pressure building into the Northern Plains.
According to Dr. Kathryn Reif, a parasitologist at Auburn University and lead author of the 2026 CAPC forecast, a "perfect storm" of factors is driving the spread — a warming climate, reforestation, and shifting interactions between animals and humans are allowing ticks to creep outside their usual areas.
The lone star tick is also on the move. Its northward expansion means veterinarians in parts of the upper Midwest and New England should now be alert to ehrlichiosis, even if it has not historically been top-of-mind in those regions.
There's a new pathogen vets are watching closely
Of all the developments this season, one stands out: the confirmation of a tick-borne illness that most pet owners — and even some clinicians — have never heard of.
Researchers at the North Carolina State University College of Veterinary Medicine recently published findings on Rickettsia finnyi, a newly confirmed tick-borne bacterium that can make dogs seriously ill. The species was named after Finny, a Colorado dog who was the first known patient — a naming choice intended to honor all the companion animals whose illnesses have contributed to the discovery of novel pathogens.
Seventeen dogs have tested positive for Rickettsia finnyi after showing fever and fatigue. Inside the body, the bacteria invade cells lining blood vessels, triggering swelling, pain, and a spotted rash.
The complication? The symptoms closely mimic Rocky Mountain spotted fever, and because the two bacteria are so similar, false positive test results for RMSF are possible when Rickettsia finnyi is actually the culprit. Standard genetic tests for RMSF may not detect it, making accurate diagnosis difficult.
Researchers believe it may be linked to the lone star tick, which is currently expanding its range northward. Its zoonotic potential — whether it can infect humans — is still under investigation.
"Tick season" is a misleading concept now
One of the most important shifts in veterinary guidance this year is the push to abandon the idea of a defined "tick season" altogether.
"Ticks don't feed 365 days a year, but they do feed 12 months a year," said Dr. Craig Prior, a CAPC board member. "Low risk does not mean no risk. Year-round prevention and annual testing are no longer optional — they're foundational."
Because some tick species can transmit pathogens year-round — and brown dog ticks can live indoors — risk is no longer limited to the traditional outdoor season.
In some regions of the US, 55% of adult blacklegged ticks and 25% of nymphs now test positive for Lyme-causing bacteria. Nymph ticks are active from May through July, are as small as poppy seeds, and are extremely easy to miss on a dog's coat.
What this means for your dog
The symptoms of tick-borne illness in dogs are easy to dismiss early on. Dogs may not look ill at first. Lyme disease, for instance, does not produce the classic bull's-eye rash seen in people. Early signs tend to be vague: shifting leg lameness, lethargy, low-grade fever, reluctance to eat. By the time a dog seems obviously unwell, the disease may have progressed significantly.
Lyme disease can lead to kidney complications or chronic joint pain in some patients, even in dogs that respond initially to treatment.
Some vet clinics are already updating their vaccine protocols in response. With tick activity rising sharply, many practices are now treating the Lyme vaccine as core protection for most dogs — not just those in historically high-risk areas.
The "One Health" angle you should know about
Veterinarians are increasingly framing tick prevention as a family issue, not just a pet issue.
"Areas where dogs face higher Lyme risk closely mirror where people contract Lyme disease — reinforcing the One Health connection between pets, people, and the environment," CAPC noted. "When canine exposure to tick-borne pathogens rises, it often signals intensifying vector activity around people as well."
Private practice veterinarians are often the first to recognize when something new is happening — a dog with an unexpected positive test result, an unusual-looking tick, a different pattern of disease. That makes veterinary teams an essential part of the broader surveillance network.
In other words: protecting your dog is also early warning infrastructure for your neighborhood.
What to do right now
The guidance from vets is consistent across the board:
Get tested annually. Many dogs with tick-borne disease show no symptoms at all. A yearly vector-borne disease panel is the only reliable way to catch infections early.
Use year-round prevention. Oral and topical preventatives (Simparica Trio, NexGard, Bravecto, and others) remain the most effective tools available. Talk to your vet about which is appropriate for your dog's lifestyle and region.
Check after every outdoor exposure. Pay particular attention to ears, between toes, under the collar, and around the groin — ticks favor warm, hidden spots. Removal with tweezers promptly after a bite significantly reduces transmission risk.
Talk to your vet about the Lyme vaccine. If you're in a newly expanding risk area — or if your dog spends time in wooded or grassy terrain — this conversation is overdue.
"If your dog doesn't seem like they feel well, has a fever, and you know they've been exposed to ticks, get them to see their veterinarian," said Dr. Barbara Qurollo of NC State's College of Veterinary Medicine. It's blunt advice, but it's the right call.
Sources: Companion Animal Parasite Council 2026 Pet Parasite Forecast; CDC; AVMA; NC State College of Veterinary Medicine; Emerging Infectious Diseases journal (CDC); dvm360; Today's Veterinary Practice.