Heartworm disease occurs when a dog or cat is infected at a high enough burden by a parasite called Dirofilaria immitis, leading to heart failure. Heartworm is acquired by a mosquito containing an infective larvae biting and depositing the larvae into the animal. It takes approximately 5-7 months for these larvae to develop into adult heartworms within the body. They tend to migrate and live within the pulmonary artery (the artery leading from the heart to the lungs).
What are the symptoms of heartworm in a dog?
Symptoms of heartworm disease include, but are not limited to coughing, exercise intolerance, inappetence, difficulties breathing, elevated respiratory rate, lethargy. In some cases, we may even see heartworm in asymptomatic dogs, meaning they have no clinical signs. This may be the case if there is a low number of worms.
How do dogs get heartworm?
Dogs contract heartworm through the bite of an infected mosquito. The mosquito carries the larvae and injects it into our pets.
What are the treatment options for heartworm?
The recommended treatment for heartworm consists of a medication that kills the adult worms. This is administered over a series of 3 deep intramuscular injections. In severe life-threatening cases, it may be recommended to remove the worms surgically if they are obstructing the heart and vessels.
Why is recovery and heartworm treatment challenging to treat?
Heartworm treatment is challenging for a few reasons. The treatment itself is risky and can lead to clot formation and blockage of blood vessels as the adult worms die. This can lead to heart failure, respiratory arrest and death. Therefore, it is absolutely essential that dogs are exercise restricted during treatment. As well, the treatment and follow up can be costly.