If you live in Minnesota, Georgia, Utah, or coastal Maine and you’ve never really stressed about tick-borne diseases in your pets, I need you to sit with this for a second: that assumption may now be genuinely dangerous. The Companion Animal Parasite Council released its 2026 Pet Parasite Forecast in March, and what surprised me most wasn’t that tick ranges are shifting. It’s how fast they’re shifting, and how many pet owners in historically “safe” zones are heading into peak tick season with zero prevention in place.

What the 2026 Forecast Actually Says

CAPC’s forecasts aren’t guesswork. They use nationwide diagnostic data, environmental modeling, and surveillance reports, and according to the CAPC 2026 Pet Parasite Forecast released March 23, 2026, their historical accuracy rate sits at 94% when checked against real diagnostic outcomes. That’s a number worth taking seriously.

The headline findings are stark. Lone star ticks are pushing northward into the Upper Midwest and New England, carrying ehrlichiosis into regions where it was barely on the radar before. Lyme disease, long associated with the Northeast and Upper Midwest, is now spreading into parts of the Midwest and Southeast. And here’s the one that genuinely caught me off guard: heartworm, which most Mountain West and Northern California pet owners considered someone else’s problem, is showing persistent elevated risk pockets in those very regions.

Dr. Kathryn Reif, lead author at Auburn University’s College of Veterinary Medicine, described 2026 as a “perfect storm” for tick spread. The drivers she points to are climate warming, reforestation, and changes in how humans and animals interact with wild spaces. None of those factors are reversing anytime soon.

The Lone Star Tick Problem Nobody Is Talking About Enough

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I’ll be honest, when most people picture dangerous ticks, they think deer ticks and Lyme. The lone star tick doesn’t get the same press coverage, but it probably should. This tick, historically concentrated in the South and Mid-Atlantic, is aggressive. It will actively pursue a host rather than simply waiting on a blade of grass. And it’s now showing up in states where veterinary clinics aren’t used to flagging ehrlichiosis as a likely diagnosis.

Ehrlichiosis in dogs can look like a lot of things. Lethargy, fever, poor appetite, sometimes bleeding problems in more advanced cases. The insidious part is that it often gets missed early because the clinical signs are vague and a vet in, say, Wisconsin or Vermont might not immediately think to run a tick panel when they’re seeing a dog with a mild fever in July. That diagnostic lag is exactly where disease spreads and animals suffer longer than they need to.

If you’re in a region newly flagged for lone star tick activity, this is worth bringing up with your vet directly. Ask specifically whether your practice has seen any confirmed ehrlichiosis cases this year. That’s useful information.

Lyme Is No Longer “A Northeast Problem”

Lyme disease expanding into the Southeast is one of those findings that flips a pretty entrenched mental model. For years, pet owners in Tennessee, Alabama, and the Carolinas were told they didn’t need to worry much about Lyme. The white-tailed deer tick, Ixodes scapularis, was considered more of a northern species. That’s changing, and as the Auburn University CVM report from May 2026 notes, the pet risk maps are now mirroring the human case distribution patterns, which is essentially the canary in the coal mine.

Dogs are excellent sentinels for Lyme exposure because they’re in the environment at ground level all the time. A dog testing positive for Lyme antibodies in a region previously considered low-risk should, and increasingly does, prompt public health officials to look harder at human exposure in that same area.

Clinically, Lyme in dogs often presents differently than in people. The classic “bull’s-eye rash” doesn’t happen in dogs. What you’re more likely to see is shifting leg lameness, reluctance to move, swollen joints, fever, and sometimes kidney involvement in more severe cases. The kidney complication, called Lyme nephritis, is particularly serious and can progress rapidly. If your dog has any of those signs and you live in a newly at-risk zone, don’t wait on this one.

Heartworm in the Mountain West: A Real Shift, Not a Fluke

The research here is unambiguous enough that the AVMA picked it up in April 2026, noting in their coverage of the CAPC forecast that year-round prevention is now essential across a much wider geographic footprint than previously advised. Heartworm has always been endemic in the Gulf Coast and Southeast. Finding persistent elevated-risk pockets in Colorado, Utah, Nevada, and Northern California is a different kind of finding.

Heartworm is transmitted by mosquitoes, not ticks, which means it tracks with different environmental factors. But warmer temperatures extending mosquito season and range explain a lot of what’s happening here. The disease itself is serious. It takes six to seven months after infection for worms to mature to adulthood in a dog, and by the time clinical signs appear, meaning coughing, exercise intolerance, weight loss, there can already be significant cardiac and pulmonary damage.

Treatment is expensive, harsh on the dog, and requires weeks of strict rest. Prevention costs a few dollars a month. This is genuinely one of the clearest cost-benefit calculations in veterinary medicine.

What Pet Owners in Newly At-Risk Zones Should Actually Do

I want to be real about what “taking action” means here, because it doesn’t have to be complicated. Start with checking CAPC’s interactive forecast map at capcvet.org and putting in your zip code. The maps are updated regularly and will give you a county-level picture of what parasites are now showing up in your area.

If you’re in a region newly flagged for tick or heartworm risk and your pet isn’t currently on prevention, that’s the most important conversation to have with your vet. Not every preventative works against every parasite, so it’s worth being specific. Ask your vet: given the 2026 CAPC forecast for our area, what combination of prevention makes sense for my dog or cat right now?

As Today’s Veterinary Practice reported in June 2026, many veterinarians are actively revising their regional prevention recommendations this year based on the new data. Your vet should know about the forecast, but if they haven’t brought it up, it’s entirely reasonable to ask about it directly.

Tick checks after outdoor time still matter even if your pet is on prevention. No product is 100% effective, and finding and removing a tick within 24 to 36 hours dramatically reduces disease transmission risk. Pay attention to areas ticks love: between toes, around ears, under collars, in groin folds, and around the tail base.

The geography of risk in the United States is genuinely different in 2026 than it was five years ago, and the data underpinning that statement is solid. If your mental map of “where tick diseases happen” hasn’t been updated recently, this is the summer to do it.

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This article is for general informational purposes only and does not constitute veterinary advice. Pet health symptoms can have many causes and require professional evaluation. Always consult a licensed veterinarian for diagnosis and treatment specific to your pet.

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