Heartworm Testing
A yearly heartworm test confirms that your dog's prevention did its job, and it has to come before the next year's supply. Petfolk Johns Creek, at Medley in Johns Creek Town Center near Johns Creek Parkway and McGinnis Ferry Road, runs the test with a small blood sample.
Most dogs get it at their annual wellness visit at our Johns Creek clinic.
Call (470) 964-6691 or book online. Open 8am–6pm, seven days a week.
When to go to a 24-hour emergency hospital
Go to a 24-hour emergency hospital if your dog collapses, struggles to breathe, has pale gums, or passes dark brown urine. Cats with sudden labored breathing also need emergency care.
Petfolk Johns Creek is open 8am to 6pm, seven days a week. We don't provide overnight care, so anything that can't wait until morning belongs at a 24-hour emergency hospital.
Why Dogs Are Tested Every Year
Prevention is very effective, but doses get missed, chews get spit out, and topicals wash off. The American Heartworm Society recommends testing every dog every year, even dogs on year-round prevention.
There's a lag. A test detects adult worms, and it can take several months after an infected bite before a test turns positive. A dose missed last summer may only show up on this year's test.
Testing matters before a refill for another reason: giving a preventive to a dog with adult heartworms can cause a serious reaction.
What the Test Looks For
A heartworm test uses one blood sample for two checks. PetMD explains that dogs are screened with an antigen test for adult heartworms and a separate test for microfilariae, the baby worms in the blood. The AHS recommends both screens yearly for dogs at least 7 months old.
Puppies younger than that can usually start prevention without a negative test first. Your vet will set the timing for the first test.
Cats are different. Heartworm in cats is hard to detect, and testing usually takes more than one kind of test. The vet will explain which tests make sense before running any.
The Blood Draw
The test needs a small sample, usually from a leg vein. You can stay by your dog's side, and our Gentle Handling team uses high-value treats instead of restraint, so most dogs are more interested in the snack than the needle. Nervous dogs can stay on the floor if the table worries them.
Fasting and sedation aren't needed for a routine heartworm test.
What Your Result Means
Negative, already on prevention: keep the plan going and set next year's test date.
Negative, not on prevention yet: choose a product that fits your dog and start it.
Positive or unclear: the vet recommends confirmation testing and walks you through what comes next.
A positive result is hard to hear. It isn't the end of the conversation, and you won't be rushed into decisions in the exam room.
“They explained everything very well and answered all of my questions”
— Viviana L., Petfolk client
Adopted Dogs and Unknown History
If your dog came from Fulton County Animal Services, another shelter, or a rescue, ask for any heartworm test results and prevention records. A dog with no history, or a gap in prevention, usually needs a test now and another one several months later, because a recent infection won't show up right away.
When You May Not Need a Test Yet
A dog tested within the past year, on prevention with no missed doses, usually doesn't need an early retest. Neither does a young puppy starting prevention for the first time. Tell the vet about any gaps, switches between products, or moves, since those can change the timing.
What Testing Costs Depend On
Whether the test is part of the annual wellness visit
Whether confirmation testing is needed after a positive or unclear result
For cats, which combination of tests the vet recommends
You'll get an estimate before the sample is drawn. PetfolkCare members get 10% off lab work.
Test, Then Refill With Confidence
Pair the test with your dog's wellness visit at Petfolk Johns Creek, and leave knowing where your dog stands and what comes next. Call (470) 964-6691 or book online.