Dirofilaria immitis is better known as a heartworm. This worm is spread by mosquitoes. Your pet does not even have to come into contact with an infected animal to pick up the parasite. This worm has a complicated lifecycle. The immature form circulates inside the bloodstream of infected pets. Mosquitoes absorb the worms when they feed on the animal’s blood. The parasite becomes a larva inside the mosquito. When the mosquito bites another pet, they can pass the larva to the animal. The worms develop inside the dog or cat and can cause a blockage. The heart and associated blood vessels can then thicken which can lead to heart failure. There may be no obvious signs when the pet is first infected. Later symptoms include coughing and lethargy and apathy. A heartworm infection can lead to heart failure and death in infected pets.

Heartworm is preventable and using a prophylactic medication such as chews, spot treatment or tablets can help prevent this potentially lethal parasite. There are also annual injections that are available for heartworm prevention. If you have not kept up to date with heartworm prevention, you should request a heartworm test before starting prevention. Follow this up with a further test 6 months later.

Our vets can advise on the best heartworm prevention for your pet.