M - F: 9am-12pm & 2pm-6pm
Sat - Sun: 9am-12pm
Early drop off appointment

PH: 847-759-1440

Fax: 847-759-1460

1445 E, Oakton St, Des Plaines, IL 60018

Heartworm Disease in Dogs and Cats

Heartworm disease is a serious and potentially fatal disease that can affect pet dogs and cats. However, heartworm disease is also found in wolves, foxes, sea lions and coyotes; and since coyotes and foxes are found in close proximity to humans, they are considered to be important carriers of the disease. 

In order to fully understand how heartworm disease is transmitted and affects dogs and cats, it helps to understand the life cycle of the worm. A heartworm goes through a total of four molts to mature into an adult worm. When a mosquito lands on an infected animal, such as one of the listed ones above or an infected stray dog or cat, it ends up sucking up the heartworm larvae eggs, known as microfilaria. Once infected, the mosquito will be the host of the first two molts (development stages) of the heartworm.

As the heartworms develop into the third stage they are able to migrate into the mosquito’s salivary glands, so when it bites your pet they burrow in through the mosquito’s small bite wound and into your pet’s blood stream. Once inside your pet it will continue its development. The juvenile adult worm will work its way into its host’s tissue all the way to the heart as early as 70 days. After entering the heart, they grow rapidly in length and size and will remain inside the heart until they die, which is typically between 5-7 years. 

The heartworms will continue to mature and when they reach adulthood they will begin to reproduce, releasing microfilaria into the blood. Without veterinary intervention, they will multiply and start to block the normal flow of blood. This process takes 6-7 months and the heartworms will not be detectable through a heartworm test until they begin reproducing. 

Therefore, prevention is key! Once the heartworms have started to reproduce they have already entered into your pet’s heart and have affected the heart’s blood flow. The treatment for heartworm disease is painful, costly and takes months to complete. So please discuss heartworm prevention with us to make sure your pet is protected!