Despite many similarities, there are important life cycle differences between the species. Do you know what they are?

Check your knowledge about the heartworm life cycle in cats by reading below!

Fact # 1: Cats are NOT the “true” host for heartworms.

• Dogs are considered the natural host and cats are considered atypical hosts.  

Fact #2: Cats usually have very few adult worms.

• In fact, according to the American Heartworm Society, “Cats with adult heartworms typically have just one to three worms, and many cats affected by heartworms have no adult worms.” ⁽³⁾

Fact #3: Cats can experience aberrant larval migration.  

• Aberrant larval migration occurs when immature adult worms fail to enter a vein and migrate to other body cavities and locations such as the central nervous system.

Fact #4: Less than 20% of cats have circulating microfilariae. ⁽⁴⁾

• For a number of reasons - such as prepatent infestations, single sex infections, prophylaxis or destruction by the host’s immune system - microfilariae is not common in cats.

Fact #5: The lifespan of adult heartworms in cats is about 2-3 years.  

• This is a big difference from dogs, where adult heartworms are known to survive 5 to 7 years. ⁽³⁾

It’s important to arm yourself with knowledge about feline heartworm disease so you understand and support your veterinarians’ recommendations to prevent this potentially deadly disease.

For more facts and information, check out this website from the experts on heartworm disease: American Heartworm Society. 

References:

1. American Heartworm Society. 
2. Cote, Etienne. Clinical Veterinary Advisor. Elsevier: St. Louis, MO
3. Heartworm basics. American Heartworm Society.
4. Parasitology. University of Florida CVM. 
5. Yin, Sophia. Veterinary Nerdbook.Cattledog Publishing