Since it is heartworm awareness month we thought we would discuss heartworm disease in cats. Yes, cats. Most people may not think that their cat can get heartworm disease and may not bother using heartworm preventive for their cat. The truth is, cats can get this devastating infection just like dogs can and even indoor cats are susceptible. One study found that close to 30% of heartworm positive cats were strictly indoors! Mosquitos transmit heartworm infection, and how many times do we find those little buggers have gotten in the house?
What are the signs of heartworm disease in cats?
Cats often have a more severe response to heartworm infection than dogs, and even a small number of heartworms can cause a real problem. Cats can have acute symptoms which arise suddenly, or they can have chronic symptoms.
| Acute symptoms | Chronic symptoms |
| Increased heart rate | Poor appetite |
| Sudden onset of difficulty breathing | Weight loss |
| Vomiting and/or diarrhea | Coughing |
| Fainting | Vomiting |
| Coughing up blood | Exercise intolerance |
| Blindness | Rapid or difficult breathing |
| Seizures | |
| Sudden death |
How is heartworm infection diagnosed in cats?
Often, if your cat is having symptoms of a respiratory problem, radiographs (x-rays) of the chest will be recommended. There may be changes noted on these that are suggestive of a heartworm problem but a normal x-ray does NOT rule out the possibility of heartworm disease.
If your veterinarian hears any abnormal heart sounds during the physical examination, they may recommend an ultrasound of the heart called an echocardiogram. It is sometimes possible to actually see the heartworms in the cat’s heart during this exam; however, they are not seen in every case.
Finally, your veterinarian may recommend a blood test to screen your cat for heartworm infection.
Unfortunately, these tests are not always perfect but are all important pieces of the puzzle to consider along with your cat’s symptoms and history.
How is heartworm disease treated in cats?
Unlike with dogs, there is not a medication that can be given to eliminate the heartworm infection in cats. Treatment in cats is mainly aimed at controlling their symptoms and reducing the risk of a complication.
Your veterinarian may start your cat on an anti-inflammatory medication such as prednisone which is meant to decrease inflammation in the lungs caused by the heartworms. Drugs that open up the airways (bronchodilators) may also be considered. Your veterinarian may also discuss starting your cat on a monthly heartworm medication.
How can I prevent my cat from having a heartworm infection?
The best thing to do is to start your cat on a monthly heartworm preventive. Just like the recommendation for dogs, cats should be on preventive year round. Even indoor cats!
