Heartworm Disease in Cats: Signs and Their Treatment

Heartworm is a fatal disease that occurs in pets (dogs and cats) due to the infection of Dirofilaria immitis. These worms typically thrive in the heart, large vessels and pulmonary arteries of the pets and can live without being noticed for almost 4-5 years. Though this disease is more prevalent in dogs, its occurrence in cats cannot be overlooked. In the latest studies made on cats suffering from respiratory or heart problems revealed that the majority of such felines had heartworm disease. Cats usually have a better immune system than dogs and hence are more resistant to heartworm infection but they still can get the infection. Thus, it is important to be cautious and know the signs that cats manifest when they have heartworms in their bodies.

6 Signs of Heartworms in Cats


Heartworms block the respiratory passages as they attach themselves to the walls of the blood vessels and hence it results in poor airflow which leads to coughing. When the condition is more severe and the heartworm volume is high, asthma-like conditions arise which are direct indications of their presence.

Recurring Vomiting

Vomiting is also another causal effect of heartworm disease. Watch out if your cat is getting periodic vomiting.

Weight Loss

Heartworms are detrimental to a cat’s health and hence can cause significant weight loss due to uneasiness and reluctance to eating proper meals.


Cats with heartworm infestation may also experience seizures and can even faint at times. This happens because the toxins these worms produce harm the body remarkably.

Difficulty Walking

Interference with the bodily functions by worms causes mobility issues and tiredness in cats thus a cat having heartworm infection may seem to have altered and lousy gait.

Accumulation Of Fluid

Fluid retention occurs as the latched worms in the heart and lungs of the cats wound the walls of the organs and vessels attached to it and thus if the cat goes undiagnosed, it may lead to heart failure.

Heartworm Associated Respiratory Disease

It is a more pronounced form of coughing, wheezing or respiratory issues that arise due to the damage caused by the worms on the vessels, arteries, and lungs over time. This is the main reason that also causes asthma in cats.

Heartworm disease in cats is atypical but if it occurs, it becomes fatal typically because of the lack of diagnosis. Since cats normally have fewer heartworms, they have more chances of not showing any symptoms and thus the first sign of heartworm disease in cats is sadly a sudden collapse. Thus, it is imperative to get your pet cat checked every 6 months for heartworms.

Diagnosis Of Heartworm Disease In Cats

Fewer adult heartworms increase the difficulty of examining their presence and even 1 or 2 worms can make the affected cat severely ill. That is the reason, the diagnosis can also be complex and may include –

  • x-ray (of the chest)
  • Complete blood work
  • Ultrasound

Though all of the above tests do help in determining the presence of the disease, many a time the results could be false negatives because of the scarcity of their count in cats. In dogs, however, it is way easier because they have a huge count of heartworms if they are affected and thus it is easier to detect these worms through blood tests. Moreover, even if they are detected, there is no actual treatment for adult heartworms. Therefore, prevention is ultimately the sure way to protect the cat from heartworm disease.

The treatment is generally palliative and may include the use of anti-inflammatory pills or injections and a few antibiotics.

Prevention of heartworms in cats is thus the only way out to combat this deadly ailment. Pet parents can opt for either oral preventatives or topical solutions. It is completely up to the convenience of the owners whichever way they want to treat their cat.  So, no matter whether your cat is an indoor cat or an outdoor cat, this disease caused by the bite of mosquitoes can infect either of them and can lead to untoward consequences. Thus, it is important to prevent the disease as it is the only way out to save your kitty.