Heartworms, which are spread by mosquitoes, have long been recognised as a dangerous threat to dogs. Wherever dogs are at risk from heartworm disease, cats are at risk, too. Unfortunately, the disease is difficult to diagnose in cats and dangerous - it can kill cats as well as dogs. Every cat exposed to mosquitoes may be at risk.

What are heartworms?

Heartworms are parasitic roundworms up to 24cm long that live in the right side of the heart and adjacent blood vessels. They survive on nutrients in the cat's bloodstream.

How can feline heartworm disease harm my cat?

Even a few adult worms in the heart can block the blood flow and cause damage to the heart, lungs and liver. Heartworms can also move to the cat's brain and spinal cord. The damage to internal organs can be so extensive that death can result. As few as two heartworms can kill a cat - often with no warning.

How do mosquitoes spread feline heartworm disease?

Heartworm lifecycle

• The cycle begins when a mosquito bites and infected animal and picks up immature heartworms from the animal's bloodstream.
• During the next two to three weeks, the immature heartworms develop into infective larvae inside the mosquito.
• When the mosquito feeds again, it transmits the infective larvae into the healthy cat.
• The larvae penetrate the skin and develop within the tissues.
• The young worms then migrate to the heart.
• Once inside the cat's heart, the worms mature and cause damage and even death.

What are the signs of feline heartworm disease?

Unfortunately, feline heartworm disease may cause much of its damage before there are any outward signs of infection. Even a cat that appears healthy can die suddenly from feline heartworm disease. A cat with heartworm disease may show one or more of the following signs:

• persistent cough
• vomiting
• general listlessness
• troubled breathing
• fatigue
• collapse

What is the treatment for feline heartworm disease?

There is no approved treatment for feline heartworm disease.

How do I protect my cat against feline heartworm disease?

Talk to your veterinarian about the monthly chewable heartworm preventative made exclusively for cats.