Simply Cat Breeds

Information on Cat Breeds from A to Z
Home Cat Breeds Cat Articles About Us Awards

Cats and Heartworms


cat at the vetHeartworm infections are less common in cats than in dogs, in fact they are likely accidental hosts as their bodies to not provide an ideal host like the body of a dog.

Heartworm Lifecycle

The heartworm, Dirofilaria immitis, infection begins when larvae in the mouthparts of a mosquito enter the cat through a bite. They burrow beneath the skin, molt twice and become small, immature worms. The first molt occurs 1-12 days after the bite. They remain in this phase for up to 68 days before molting again to become the worms. These worms then make their way into a peripheral vein where they are carried to the right ventricle of the heart and the pulmonary arteries. In cats, they may also become disoriented and move into body cavities and the central nervous system. Approximately six months after entering the hosts body, they mature into adults that can be up to 12 inches long and live for two to three years.

Mature heartworms produce larvae, called microfilaria, that circulate in the blood stream. This is much less common in cats than dogs, possibly because the cat’s immune system kills the larvae off very quickly.

Symptoms of Heartworm Disease

Cats have a very small heart, so even a small infestation of only one or two worms can be enough to cause very serious heart trouble or even sudden death. Symptoms can include a cough made worse by exercise, lethargy, sudden weight loss and change in coat condition, and bloody sputum or phlegm. It may appear that the cat as asthma or allergic bronchitis.

If the cat survives this phase, they should be fine until the worms die in two to three years. During this phase, symptoms including labored breathing and other low-grade but chronic respiratory signs may occur, congestive heart failure, heart murmur, loss of appetite and change in coat condition may occur again, as well as intermittent vomiting. If an autopsy is performed, worms may be discovered.

Diagnosis is simple and is generally performed through a blood test that looks for the heartworm antigen and antibodies. X-rays and echocardiography are also helpful in making a diagnosis

How To Prevent A Heartworm Infection

Heartworms are spread by mosquito’s, so the best way to protect your cat from heartworms is to remove the threat of mosquito’s. Even indoor cats can be infected if a mosquito makes its way inside. There are also a number of products that can be administered to help prevent heartworms: Revolution, Heartgard, and Interceptor are three of the better known.

Your cat does not have to be tested before these preventative measures can be administered, but it is certainly recommended.

At this time there are few treatments for cats with heartworms. Ivermectin is used but it is still considered an experimental treatment, and surgery can be utilized but it is very risky. It is best to simply use preventative measures and be careful in eradicating mosquitos from around your home.



Related Articles


Tips For Managing Feline Arthritis
Chronic Renal Failure
Declawing Your Cat
Emergency Symptoms in Your Cat
Cats and Eye Inflammation
Cats - Dealing With Fleas
Feline Lower Urinary Tract Disease
Cats and Gastritis
Hyperthyroidism In Cats
Is My Cat In Heat?
Quick Guide to Feline Leukemia
Common Skin Problems in Cats
Best Flea Control For Cats
Cats and Upper Respiratory Tract Infection
Cat Vaccines - What To Know
Common Causes for Cat Vomiting
A Personal Tale of The Amazing Cancer Cat

When to Euthanize Your Cat
How Long Will My Cat Live?
Why Declawing Your Cat Is a Bad Decision
Managing a Diabetic Cat
Three Different Pet Meds for Cats
Did You Know That Cat Scratch Fever Really Exists?
Can Cats Have Allergies?