Every dog in Charlotte should get heartworm prevention every month, all year, and cats benefit from it too, because one mosquito bite can pass heartworm larvae to a pet. The American Heartworm Society recommends year-round prevention and a heartworm test every year for all dogs. Petfolk SouthPark is a veterinary clinic in Charlotte, North Carolina, on Old Sardis Road, where our veterinarian in SouthPark prescribes prevention by your pet's weight and age.
Puppies can usually start prevention at about 8 weeks old.
Call (980) 580-8079 or book online.
How do dogs and cats get heartworms?
Dogs and cats get heartworms from mosquitoes. A mosquito bites an infected animal, often a coyote, fox or another dog, and picks up tiny immature worms called microfilariae. Inside the mosquito they grow into larvae. When that mosquito bites your pet, the larvae enter through the bite and travel through the body for months. In dogs they settle in the heart and the large blood vessels of the lungs and can grow to about a foot long.
Prevention works by killing the larvae your pet picked up over the previous weeks, before they grow into adults. That is why it has to be given on time, every time.
Does my dog need heartworm prevention all year in Charlotte?
Yes. The American Heartworm Society recommends year-round prevention for dogs, and in its May 2026 release said heartworm is most common in warm, humid regions and is spreading into areas once thought rare.
Local heartworm data. About 1 in 200 dogs tested in Mecklenburg County were positive for heartworm in 2025 (0.63%, Companion Animal Parasite Council county map).
Local mosquitoes. Mecklenburg County Public Health reported West Nile virus in a mosquito pool collected on July 14, 2026. West Nile is a different disease, but it shows mosquitoes were biting in the county in July 2026.
Mild winters. Warm spells can bring mosquitoes back out, and a dose skipped "because it's cold" leaves a gap you can't see.
How do SouthPark pets get their heartworm prevention?
Petfolk SouthPark records from October 2025 to September 2026 show prevention is a routine part of visits:
Two in three puppy wellness visits at Petfolk SouthPark (66%) ended with heartworm, flea and tick prevention going home.
About 3 in 10 wellness visits for adult dogs (31%) included heartworm prevention.
Of dog parasite-prevention purchases at Petfolk SouthPark, 87% were Simparica Trio, a monthly chew covering heartworm, fleas and ticks, and about 6% were ProHeart 12, a yearly injection.
What kinds of heartworm prevention are there?
At Petfolk SouthPark, heartworm prevention comes in three main forms, and all of them need a veterinarian's prescription.
Monthly chewables or tablets. Many also treat some intestinal worms, and some cover fleas and ticks.
Monthly topical liquids. Applied to the skin between the shoulder blades; the usual choice for cats.
A long-acting injection for dogs. Given by a veterinarian, covering many months at once.
The best one is the one your household will give on schedule. A chew your dog spits out behind the couch protects nothing.
Why does my dog need a heartworm test before starting?
A dog over about seven months old gets a blood test before starting prevention, because prevention won't clear adult worms and starting it in an infected dog can cause a reaction as larvae in the blood die off. After that, the test is yearly. The heartworm testing page explains the test and what a positive result means.
Do indoor cats need heartworm prevention?
Yes, the American Heartworm Society advises it, because mosquitoes get indoors and there is no approved treatment to clear heartworms from a cat. In cats, even immature worms can inflame the lungs and cause coughing, wheezing or vomiting that looks like asthma. Monthly topical products made for cats are the usual approach at Petfolk SouthPark.
How can I cut mosquito bites at home?
Mecklenburg County's advice is to empty standing water at least once a week. Tip out flowerpot saucers, kiddie pools, buckets and clogged gutters, and change the water in pet bowls and birdbaths often. It won't replace prevention, but fewer mosquitoes means fewer chances.
What heartworm signs need a 24-hour hospital?
Go to a 24-hour emergency hospital if your dog suddenly collapses, has pale gums, struggles to breathe or passes dark, coffee-colored urine. Those can be signs of severe heartworm disease. Petfolk SouthPark is open 8 AM to 6 PM, seven days a week, and doesn't provide overnight care.
How do I start heartworm prevention at Petfolk SouthPark?
Book a wellness exam, which starts at $99 or is included with a PetfolkCare plan; prevention is priced by product and your pet's weight. Petfolk Veterinary & Urgent Care - SouthPark is at 4914 Old Sardis Rd, Unit C5, Charlotte, NC 28211. Call (980) 580-8079 or book online.
Book a visit at Petfolk Veterinary & Urgent Care - SouthPark, or see all veterinary services in SouthPark.
Heartworm prevention, plainly answered
Look for Unit C5 on Old Sardis Road