Every dog needs a heartworm blood test once a year, even on year-round prevention, and again before starting or restarting a preventive. Petfolk Veterinary & Urgent Care - Ballantyne, at 5335 Ballantyne Commons Pkwy, Suite 150, Charlotte, NC 28277, runs heartworm tests for dogs from a few drops of blood, and the result tells the doctor which preventive is safe to give.
Heartworm disease spreads through mosquito bites and does its harm quietly, so most infected dogs look normal for a long time. Petfolk Ballantyne is a vet in Ballantyne for dogs and cats.
Call (980) 300-6982 or book online.
Why does a dog on prevention still need a yearly heartworm test?
Doses get missed, spat out or given late, and no product is perfect. The American Heartworm Society recommends year-round prevention and an annual test for all dogs. A negative result tells the Petfolk Ballantyne doctor that the preventive is working and safe to keep giving.
Bring the product name and the date of the last dose, or a photo of the box. Missed doses are common, and nobody at the clinic will judge you for one.
What the blood test looks for
The standard screen looks for an antigen, a protein released by adult female heartworms. A positive result means adult worms are living in the heart or the vessels of the lungs.
If the antigen test is positive, the doctor usually checks the blood for microfilariae, the tiny young worms that adults release. Finding them confirms the infection and affects which medicines are safe to give first. Gentle handling is standard at every Petfolk clinic, so the blood draw is quick, calm and done with your dog settled.
Why can a heartworm test miss a recent infection?
Larvae from a mosquito bite take about six months to grow into adults that the test can detect. A negative result in March only covers bites from roughly the previous fall. That is why the doctor asks when prevention lapsed and may recommend a second test about six months after you restart.
The same delay explains the puppy rule. Puppies younger than about seven months usually start prevention without a test, then get their first test about six months later and yearly after that.
Heartworm in Mecklenburg County
About 0.63% of dogs tested in Mecklenburg County in 2025 were positive for heartworm, according to Companion Animal Parasite Council data. The American Heartworm Society places North Carolina among the states reporting the most cases.
Mosquitoes breed in very little water: a clogged gutter, a plant saucer, a dog bowl left on the deck. A lake loop at Colonel Francis J. Beatty Park or an evening walk around the block means time near standing water, which is why the yearly test exists.
At Petfolk Ballantyne, 46% of adult dog wellness visits included a heartworm test between October 2025 and September 2026, rising to 53% for dogs 7 and older. If you are restarting or switching products, the heartworm prevention page walks through the options, and the test usually happens at the same visit.
How are cats tested for heartworm?
Cats often carry only one or two worms, sometimes all male, and the antigen test can miss them. The doctor may combine an antigen test with an antibody test, which shows exposure, and sometimes chest X-rays. A cat's result is read alongside signs such as coughing, wheezing or vomiting.
What a visit costs
The test is usually done at a wellness exam, which starts at $99 or is included with PetfolkCare. You'll get an estimate before any test or treatment. The final bill can differ if the plan changes during the visit.
When to skip the wait
Go to a 24-hour emergency hospital if a dog suddenly collapses, has pale gums, breathes with great effort or passes dark brown urine. Those signs can mean a large worm burden is blocking blood flow. Petfolk Ballantyne is not a 24-hour hospital. For anything milder, call (980) 300-6982.
Book a visit at Petfolk Veterinary & Urgent Care - Ballantyne, or see all veterinary services in Ballantyne.
Common questions about the heartworm test
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