Connecticut's state tick lab opened submissions in early April and got buried. More than a hundred ticks arrived in a single day. Forty percent of them tested positive for the bacterium that causes Lyme disease. Goudarz Molaei, the medical entomologist who runs the program, called the activity "disconcerting" — and that was before nymph season had even started.
This is the spring to take ticks seriously, and not in the abstract way pet articles usually mean it. The 2026 outlook across the Northeast is uglier than any season in nearly a decade. The CDC's Tick Bite Tracker, logging emergency-room visits since 2017, just reported the highest April rate on record: roughly 163 per 100,000 people across the Northeast, nearly double the national average. Where humans get bitten, pets get bitten more. They live closer to the ground, spend longer outside, and most of them can't tell you when something is crawling on them.
What's different about 2026? A mild winter never broke the adult tick population the way colder seasons used to. Mouse numbers — the reservoir for Borrelia burgdorferi — surged in 2024 and 2025. And the invasives have settled in. The Asian longhorned tick, first found on a New Jersey sheep in 2017, was confirmed in Maine last summer. Single females reproduce without mating, which means one tick can found an entire population. Lone star ticks, historically a southern species, now breed in Suffolk County, Newport County, Fairfield County, and the Cape and Islands. Dr. Kathryn Reif of Auburn University, who led the 2026 CAPC Pet Parasite Forecast, put it bluntly: a perfect storm.
What's actually out there
Five tick species do most of the damage to Northeast pets in 2026, and the differences matter.
The blacklegged tick — the deer tick — is the one your dog is most likely to bring home. Adults are sesame-seed sized; nymphs are the size of a poppy seed. They live in leaf litter, woodland edges, and any lawn that borders trees. They carry Lyme disease, anaplasmosis, babesiosis, Borrelia miyamotoi, and Powassan virus — sometimes more than one at a time. Adults can bite any winter day the ground temperature climbs above 45°F. Nymphs, the dangerous ones because they're nearly invisible, emerge in late May and stay active through July.
The American dog tick is the bigger, mottled gray-brown tick people spot crawling up a leg. It carries Rocky Mountain spotted fever — the deadliest tick-borne disease in North America, with untreated case fatality above 30 percent in humans. The lone star tick is aggressive and fast, and instead of waiting to be brushed against will actively pursue a host. It transmits ehrlichiosis and, for cats, Cytauxzoon felis — a protozoal infection that can kill a healthy adult cat in under a week.
The brown dog tick is the indoor exception, capable of completing its full life cycle inside a house or kennel. The Asian longhorned tick is the wildcard. Connecticut researchers found Ehrlichia chaffeensis DNA in collected specimens in 2025, suggesting it may become a vector for canine ehrlichiosis in the region. We don't know yet how dangerous it will turn out to be. We do know its populations are exploding.
The diseases pets actually get
Lyme is the headline, and also the most overestimated in pets. Roughly 95 percent of dogs exposed to Borrelia burgdorferi never develop clinical illness. The other five percent get shifting-leg lameness, fever, swollen lymph nodes, and — in retrievers and Bernese mountain dogs especially — a kidney complication called Lyme nephritis that can be fatal. Doxycycline clears most uncomplicated cases. Cats, oddly, almost never develop clinical Lyme. The disease is essentially a canine and human problem.
Anaplasmosis has caught up. In some Northeast practices, more dogs now test positive for anaplasmosis than for Lyme. Symptoms — fever, lethargy, joint pain, low platelets — look almost identical, and the treatment is the same. Ehrlichiosis, babesiosis, and Rocky Mountain spotted fever round out the canine list. Co-infections are increasingly common, because the same tick can carry several pathogens at once.
For cat owners, the threat to watch is cytauxzoonosis. As lone star ticks push north into southern New England and the islands, the risk creeps closer. Untreated, it kills the majority of infected cats within a week. Even with current best therapy — atovaquone and azithromycin plus aggressive supportive care — survival is about 60 percent. Indoor-only is the single most effective protection.
What pet owners miss most often is the timing. Dogs don't develop a bull's-eye rash. The lameness, fever, or appetite loss that signals Lyme or anaplasmosis typically shows up two to five months after the bite — long after most owners have forgotten there was one. Ehrlichiosis can go chronic and surface a year later as unexplained bruising or bone-marrow suppression. Cytauxzoonosis hits in five to twenty days and moves fast. If your pet was bitten and seems off weeks later, the tick is still the first thing your veterinarian should rule out.
What works for prevention, and what doesn't
The category that has changed pet protection most in the last decade is the isoxazoline class — afoxolaner, fluralaner, sarolaner, lotilaner. Oral chewables in this family kill ticks systemically within 8 to 12 hours of attachment, fast enough to prevent transmission of most pathogens. In July 2025 the FDA approved Bravecto Quantum, the first 12-month injectable, and in March 2026 expanded its label to cover Asian longhorned and Gulf Coast ticks. NexGard Plus and Credelio gained expanded tick coverage in 2025. These products aren't perfect — the FDA's 2018 neurologic adverse event warning is still in force, and dogs with seizure histories need a careful conversation with their veterinarian — but they are the most effective tools available.
Topicals and tick collars still have their place, especially for cats. The imidacloprid-flumethrin collar has documented efficacy against Cytauxzoon transmission and protection that lasts up to eight months. What doesn't work: essential oil sprays, garlic supplements, diatomaceous earth, amber resin collars. They sell well. They do not prevent disease in endemic regions.
Now the part that kills cats every year: permethrin. Cats lack the liver enzyme to metabolize pyrethroid compounds, and the concentrations used in canine spot-on products are routinely fatal to a cat that grooms a treated dog or sleeps on a shared blanket. The American Veterinary Medical Association's position is unambiguous — never apply any tick product to a cat without veterinary approval, and in a mixed-pet household, choose alternatives that don't put the cat at risk. This isn't theoretical. Animal poison control centers field these cases constantly.
Year-round prevention is no longer a marketing line from the manufacturers. CAPC, the CDC, the AVMA, and the AAHA all aligned on the same message in 2026: ticks feed twelve months a year now, even if not every day, and the seasonal model is obsolete in the Northeast.
What to do now
If your dog or cat has been off prevention through the winter, restart this week, before nymphs emerge in May. Ask your veterinarian for a SNAP 4Dx Plus screening — it covers heartworm, Lyme, anaplasmosis, and ehrlichiosis in a single in-house test — and add a urine protein check for any seropositive dog. Discuss the Lyme vaccine honestly: it's a lifestyle vaccine, not a universal recommendation, and the right answer depends on your county, your dog's exposure, and your tolerance for the small remaining risk of clinical disease.
After every outdoor outing, run your hands through the coat. Check ears, armpits, groin, between toes, around the tail base. On cats, focus on the head and neck where grooming can't reach. If you find a tick, remove it with fine-tipped tweezers, grasping the head as close to the skin as possible, and pull straight up with steady pressure. No twisting. No matches. No petroleum jelly. Save the tick in a labeled bag — the University of Massachusetts, UConn, and the University of Maine extension all run testing programs.
Treat the yard like the perimeter it is. A three-foot barrier of wood chips or gravel between lawn and woods reduces tick migration. Mow short. Clear leaf litter. Move bird feeders and woodpiles away from the house. If your property backs to forest in Connecticut, Long Island, the Hudson Valley, Cape Cod, or southern Maine, a licensed acaricide application in May and August is worth the cost.
The strongest single thing you can do this season is also the most boring: pick a prevention product appropriate to your pet's species and your region, and use it without fail. The 2026 forecast is bad. The tools that exist now are better than they have ever been. The gap between those two facts is closed entirely by what you do this month.
■ Filed under Preventive Care. Corrections: corrections@proactivepethealth.com