Heartworm in Cats: Causes, Symptoms, Treatment

Heartworms are a type of parasitic worm that primarily affect dogs, but cats can also be affected. Heartworm infections occur across mainland Australia, but they are particularly prevalent in areas where mosquitoes are more common (tropical regions).

Mosquitoes transmit both heartworm in cats and heartworm in dogs. Dogs are the primary host of heartworm. Adult female heartworms living in an infested dog produce tiny juvenile worms called microfilariae. When a mosquito takes a blood meal from a dog with circulating microfilariae, some of these are taken up. After a short period of development in the mosquito, these juvenile worms can be passed to another dog (or cat) when the mosquito takes another blood meal.

Heartworm disease in cats can be very serious. Symptoms of heartworm in cats may include:

• Coughing
• Difficulty breathing
• Vomiting
• Decreased appetite
• Weight loss
• Difficulty walking
• Fainting
• Fluid accumulation in the abdomen

Unfortunately, the first heartworm sign in some cases is sudden collapse or sudden death.

Unfortunately, there is no approved drug to treat existing heartworm infections in cats and the prescription medication used by vets for heartworm treatment in dogs is not safe for cats. Your vet may recommend other supportive care options.