DATA-BACKED GUIDE · UPDATED JULY 2026
How Much Does a Heartworm Test Cost for a Dog?
The heartworm test is a quick blood test your vet runs, usually once a year before refilling prevention. On its own it is not expensive, but it often rides along with an office visit and the next year of preventive meds, so the visit as a whole costs more than the test line suggests. Here is what the test is, why vets insist on it, and what drives the price.
The quick version
- The heartworm test is a simple in-house blood test, usually done annually.
- Most vets require a current negative test before they will prescribe prevention.
- The test itself is cheap, so the office visit and the prevention are the bigger costs.
- Cats are tested differently and less often than dogs, and testing is trickier.
- Prices vary by region, with the mosquito-heavy South testing more routinely.
What people actually paid
The gap: advertised vs actually paid (medians)
People reported paying 71% more than the advertised list price for heartworm.
List prices are advertised prices; paid figures are what people reported, often for different cases. Treat the gap as a signal, not a quote.
Real prices, in people's own words
- $35“Heart worm rest 35, rabies 14.15 and dhpp 24.15”
- $36“Both dogs received Zoetis (ZD) heartworm rapid test $36.00 Bordetella Oral $23.00”
- $48“Heart worm 48.30”
- $65“Liberty Veterinary Clinic, Diag.Lab.Snap Test $65”
- $73“Annual Vaccines & Heartworm Injection, Total: $73, preventative care for dog”
- $104“Confirmation Blood Panel $104”
Genuine amounts posted publicly. We publish the price and the quote, never the person.
Why the price varies so much
The test is a small, fairly standard cost, so most of the variation is around it. The office visit fee, whether the test is bundled into an annual exam or charged on its own, and your region all move the total. Heartworm is far more common in warm, mosquito-heavy states, so vets in the South test and treat more aggressively than in colder areas. Whether you buy prevention from your vet or an online pharmacy also makes a real difference to the yearly heartworm total, even though that is prevention rather than the test itself.
How to pay less
- Ask whether the test can be bundled into your pet's annual wellness visit to avoid a separate fee.
- Buy the actual prevention through Chewy Pharmacy or check GoodRx for Pets, which is often cheaper than in-house.
- Look for low-cost clinics and shelter events that offer heartworm testing at a reduced rate.
- Ask whether a longer-interval test is appropriate for a dog kept strictly on year-round prevention.
- Buy prevention in larger multi-month packs, which usually lowers the per-dose price.
- Check for manufacturer rebates on prevention brands, since they run promotions regularly.
Common questions
Why do I need a heartworm test every year if my dog is on prevention?
Because no prevention is perfect, and a missed or vomited dose can leave a gap. Giving preventive to a dog that already has heartworms can be dangerous, so vets test first to be safe. The American Heartworm Society recommends annual testing even for dogs kept on prevention year-round, and many manufacturers also require a recent negative test to honor their product guarantee.
Can I skip the test and just buy prevention online?
You still need a prescription, and most vets and pharmacies want a current negative test before filling it. Skipping the test to self-medicate risks giving prevention to an infected dog, which can cause serious reactions.
Do cats need heartworm testing too?
Cats can get heartworm, but testing is more complicated and less routine than in dogs, and there is no approved treatment for cats once infected, so prevention matters even more. Your vet will advise based on your area and your cat's lifestyle.
How long does the test take?
The common in-house antigen test uses a few drops of blood and gives results in about ten minutes, so you usually get the answer during the same visit. Some clinics send it to an outside lab instead, which takes a day or two.
What happens if the test is positive?
Treatment is a longer, more expensive process than prevention, involving confirmation testing, medication over several weeks, and strict rest. That gap between cheap prevention and costly treatment is exactly why vets push year-round prevention.