Heartworm is a worm which lives in the heart and blood vessels of dogs and less commonly cats. Transmitted by mosquitoes, it has the potential to cause serious, chronic and fatal heart and lung disease in unprotected pets. Humans can occasionally be infected with heartworm with severe consequences.
How heartworm is transmitted from pet to pet
Adult heartworms are about 20cm long and 1mm in diameter and live in the heart and blood vessels going to the lungs. They produce larval offspring called microfilaria that float around the blood stream. Mosquitoes suck blood containing microfilaria from infected animals and then transmit these larvae from animal to animal. After initial infection these larvae take approximately six months to develop into adult worms which reside in the pet’s heart.
Symptoms of heartworm infection
Heartworm physically blocks the heart and lungs causing problems with the function of these organs. Clinical signs of heartworm disease are varied but may include coughing, sluggishness and difficulty breathing. Some infected animals may show no signs of the disease at all.
Diagnosis and treatment of heartworm infection
Heartworm infection is diagnosed by performing a simple blood test with results available within 10 minutes. As dead worms aren’t voided from the body the blood flow pushes the dead worms from the heart into the lungs causing lung disease. Animals that are infected with heartworm are treated slowly to minimise the effects of the dead worms on the health and survival of your pet. Treatment can be expensive and dangerous especially if there are many worms present.
Prevention of heartworm
The good news is heartworm is completely preventable. Many products are available to prevent heartworm disease.
For dogs we recommend Proheart Injection. Proheart injection is given annually and ensures that no doses are missed which is a common occurrence when using monthly tablets/spot ons.
For cats we recommend Advocate. Advocate is a monthly spot on treatment that not only prevents heartworm but also prevents fleas, mites and some intestinal worms.
IMPORTANT – Never give heartworm tablets to an animal which may have heartworm (has missed treatment or has not been on a heartworm preventative previously). If your pet has missed treatments speak to your vet before giving any heartworm preventative.