Last April, a client of mine brought in Bailey, a seven-year-old Golden Retriever who’d been limping on his left front leg for a week. “He just seemed stiff after fetch,” she told me. By the time she’d scheduled the appointment, the limp had jumped to his right hind leg — and that little detail, lameness that migrates from leg to leg, is what made me reach for a Lyme test before I even finished the exam. It came back positive. What surprised her most was what I said next: her two cats, who roam the same woods behind her house, were almost certainly fine — but they might be the bigger problem in her household. Welcome to the strange, lopsided world of ticks, dogs, and cats.
One Bug, Two Very Different Species
Lyme disease in dogs is caused by the bacterium Borrelia burgdorferi, delivered by the bite of an infected blacklegged tick. Dogs are remarkably susceptible to infection — but here’s the part most owners don’t know: roughly 90 to 95 percent of exposed dogs never show a single symptom. Their immune systems handle it quietly. When dogs do get sick, the classic picture is what Bailey had: shifting lameness (limping that moves between legs), fever, lethargy, and swollen joints. There’s also a rare but serious kidney form called Lyme nephritis, which is why a positive test in a Labrador or Golden — breeds that seem overrepresented — always gets my attention rather than a shrug.
Cats are a different story entirely. Clinical Lyme disease in cats is documented but rare, and the explanations are genuinely interesting. First, cats are obsessive groomers — they often pluck ticks off their own skin within hours, well before the 24-to-48-hour attachment window the bacterium needs to transmit. Second, there appears to be real immunological resistance. But a,[1] made me reconsider how settled that “cats don’t get Lyme” wisdom really is. The authors argue cats may be underdiagnosed simply because we barely test them and rarely put preventives on them — not because they’re truly bulletproof. When cats do show illness, the signs are vague: low energy, a stiff gait, poor appetite. Easy things to miss in a cat who naps sixteen hours a day anyway.
Cats rarely get Lyme disease themselves — but they’re excellent at giving infected ticks a ride into your living room.
The Silent Taxi: What Your Cat Carries Home
Here’s the fact I wish every outdoor-cat owner knew: Lyme disease can’t jump directly from a dog or cat to a person, but [2] where those ticks can finish their meal on a human family member. I once had a client find an engorged tick on her sofa cushion — Olive, her gray tabby, regularly slept there with the kids. Nobody in that house owned a dog. The cat was the whole supply chain.
Research suggests cats may actually face higher tick exposure than dogs precisely because so few of them receive any protection — no collars, no topicals, nothing. Which brings me to the warning I give every multi-pet household.
Never borrow your dog’s product for your cat
Many dog flea-and-tick spot-ons contain permethrin, which cats cannot metabolize. Applied to a cat — or licked off a recently treated dog before the product dries — it can cause tremors and seizures. This is one of the most common poisoning calls in veterinary medicine, and it’s preventable. Read every label, confirm the species and weight range, and keep cats separated from freshly treated dogs until the application site is completely dry.
Prevention That Actually Works
Choosing the right product
For tick prevention in dogs, I lean on three categories: oral chews in the isoxazoline class (they kill attached ticks within hours — comfortably inside the Lyme transmission window), topical spot-ons, and long-acting collars. What matters more than the format: it should be labeled for your pet’s species and weight, effective against the tick species in your area, and ideally prescribed or endorsed by your vet rather than grabbed off a shelf on instinct. For cats, safe options exist but the menu is shorter — another reason cat owners often skip protection, and a problem worth solving with your vet rather than avoiding.
I’ll admit something here: for years, I told clients they could pause preventives over winter. I’ve changed my mind. Ticks become active whenever temperatures climb above roughly 40°F (4°C), and our winters keep offering those thaws. Most of my colleagues now recommend year-round coverage, and I’ve joined them.
Testing and vaccination
Most clinics run a quick annual blood screen that checks for Lyme antibodies alongside anaplasmosis and ehrlichiosis — two coinfections carried by the same ticks. A canine Lyme vaccine exists (there’s no feline version), and consensus guidelines support it in endemic regions, though reasonable vets still debate how broadly to use it given how many dogs never get sick. There’s also genuine, ongoing debate about whether healthy, positive dogs need antibiotics like doxycycline or just monitoring — that’s a conversation to have with your own vet, not a decision to make from an article. A [3] is worth bookmarking so you know what warrants a phone call.
The sixty-second tick check
Because a tick generally needs 24 to 48 hours of attachment to transmit Lyme, a quick daily once-over is genuinely protective. On dogs and cats alike, focus on ears, armpits, between toes, the groin, under collars, and around eyelids. If you find one, skip the folklore — no Vaseline, no burning match, no twisting. I understand the impulse behind the home remedies; suffocating the tick sounds logical. But irritating it can actually make it regurgitate into the bite. Instead, grasp the mouthparts with fine-tipped tweezers, pull straight out with steady pressure, and dab the site. Snap a photo of the tick if you want it identified later.
Your Seasonal Tick Calendar
Tick season varies enormously by geography, and the poppy-seed-sized nymph stage — the one behind most human infections — peaks in the warm months when it’s easiest to miss. If you’re in North America, here’s the shape of your year:
- Northeast and Mid-Atlantic: nymph peak May through July; adult surges in March–April and again October–November.
- Upper Midwest: similar pattern, compressed — heaviest activity May through August.
- Southeast: nearly year-round activity, with more species in play, including lone star ticks (whose bites can trigger alpha-gal syndrome, a red-meat allergy — a real concern for hikers) and Gulf Coast ticks.
- West Coast: a genuinely odd pattern — western blacklegged tick adults are most active December through May. Your “off-season” is summer.
Two newer wrinkles: the Asian longhorned tick, first detected in the U.S. in 2017, has now spread across many states and can reproduce without mating, and warming winters are pushing blacklegged ticks north into Canada and to higher elevations. If you live outside North America, ask your vet about local tick seasonality — the biology travels, but the calendar doesn’t.
The Conservation Twist Behind the Tick Boom
Here’s the part I find fascinating, in a bittersweet way: ticks are booming partly because of conservation wins. White-tailed deer were nearly wiped out in parts of the Northeast by 1900; protection and habitat recovery brought them roaring back. Meanwhile, abandoned farms reverted to forest. The result is ideal tick country — deer aren’t the source of the Lyme bacterium (that distinction belongs mostly to white-footed mice), but they’re the dining table where adult ticks feed and breed. We rebuilt an ecosystem, and ticks moved in right behind it.
You can’t undo a conservation success, and you wouldn’t want to. What you can do is manage your own patch: mow regularly, clear leaf litter, and consider a three-foot barrier of wood chips between lawn and woods to give ticks a dry, hostile no-man’s-land to cross. Keep playsets and patios away from the yard’s edge.
So that’s my takeaway after twenty years of pulling ticks off other people’s dogs: the tick boom is an ecological feedback loop we created by healing a landscape — and it’s a loop we live with smarter, not fearfully. Year-round prevention matched to each species, an annual test for your dog, a sixty-second tick check at the door, and a yard that’s a little less hospitable. Bailey recovered fully, by the way, and his owner now checks the cats too. Smart woman. The deer, the mice, and the ticks aren’t going anywhere — but neither, done right, is the health of the animals and people sharing that recovering forest with them.
Sources
- 2024 review of Lyme in companion animals — pmc.ncbi.nlm.nih.gov
- pets sharing our environment can carry infected ticks indoors — facebook.com
- good overview of tick-borne disease signs — mcmoniglevet.com