No, heartworm cannot be directly transferred from dogs to cats; both species require a mosquito vector to become infected with Dirofilaria immitis.
Can my cat get heartworms?
Yes, cats can and do get heartworms, though less commonly than dogs.
Cats aren't the ideal hosts like dogs are. Most worms don’t reach adulthood in cats, but the larvae can still wreak havoc on their respiratory system—sometimes even causing sudden death. According to the American Heartworm Society, cats get infected just like dogs, but symptoms often don’t show up until the damage is already severe.
Is heartworm contagious between dogs and cats?
No, heartworm is not contagious between pets of any species.
Here’s how it works: a mosquito bites an infected animal, then bites a healthy one within 10–14 days. Dogs need consistent prevention to stop the cycle, but direct contact? Doesn’t spread heartworm at all.
What are the first signs of heartworms in cats?
Early signs often include intermittent vomiting, coughing, rapid or difficult breathing, and lethargy.
These symptoms look a lot like feline asthma or bronchitis, which makes diagnosis tricky. In some cats, the first clue is sudden respiratory distress—or worse, sudden death. If your cat shows these signs, get to the vet ASAP. Cats with persistent symptoms may need long-term supportive care to manage lung inflammation.
What if my cat has heartworms?
There is no FDA-approved drug to kill adult heartworms in cats.
Treatment focuses on easing symptoms with steroids and bronchodilators. In rare cases, surgery removes worms spotted on ultrasound. Cats with serious breathing problems need hospitalization and oxygen. Your vet will tailor a plan based on your cat’s specific needs. For dogs, however, ivermectin-based protocols are often used for treatment.
Should cats be on heartworm prevention?
Yes, all cats—indoor and outdoor—should receive monthly heartworm prevention.
Monthly meds like ivermectin, milbemycin, or moxidectin stop larvae from growing into adults. The ASPCA insists on year-round prevention—mosquitoes don’t take winter breaks.
How do cats catch heartworm?
Cats become infected when an infected mosquito bites them.
That mosquito leaves larvae behind, which travel through the cat’s body and end up in the heart or lungs. Outdoor cats are at higher risk, but indoor cats aren’t safe—mosquitoes sneak inside. Areas with high mosquito populations pose the greatest threat, so prevention timing matters.
How likely is heartworm in cats?
Heartworm prevalence in cats is estimated at 5% to 15% of that seen in dogs not on preventive medication.
The American Heartworm Society warns that infection rates depend on location—warmer, humid areas are riskier. Even a small percentage still means thousands of cats get infected nationwide.
Can cats recover from heartworm?
Some cats may clear the infection naturally, but lung damage can be permanent.
Some cats bounce back on their own, but many end up with lasting lung problems. Even if they survive the larval stage, chronic inflammation often lingers. Vets usually recommend regular chest X-rays for cats exposed but showing no symptoms. Dogs, on the other hand, have more treatment options like ProHeart injections to aid recovery.
Can a dog fully recover from heartworms?
Yes, dogs can fully recover from heartworm disease with appropriate treatment and follow-up.
Dogs get melarsomine shots to kill adult worms, then must stay calm—no running, no jumping. The AKC says early treatment and strict care lead to full recovery in most cases.
How do you check a cat for heartworms?
Veterinarians use a combination of blood tests, X-rays, and heart ultrasound.
Antigen and antibody tests spot exposure, X-rays show lung and heart changes, and ultrasound can reveal adult worms. No single test is foolproof, so vets often use several to confirm.
Edited and fact-checked by the FixAnswer editorial team.
