We used to think that cats rarely got heartworm disease, but new studies have been done indicating feline heartworm disease is much more prevalent than previously thought. Cats can be infected at any age and most heartworm infections consist of 6 or less adult worms. Though the disease is much more common in dogs, cats are also prone to it. Due to the small size of a cat's heart, only 1 heartworm can cause significant illness. Signs of heartworm disease include, but are not limited to, coughing, lethargy, vomiting that is not related to eating, collapse, seizures and respiratory problems.
Some cats show no early symptoms and can die without warning.
Unlike dogs, testing for heartworms in cats can be very difficult due to the small number of worms usually present. At this time there is not an approved treatment for the removal of heartworms in cats, though different products are being studied. Veterinarians can, however, give infected cats certain medications to make them more comfortable. Fortunately, there is a new product that has been approved for cats which prevents heartworm disease. The heartworm preventative that is used for dogs is NOT for use in cats, since the dosages are very different.