For this month’s issue, we will be focusing on a disease known as Canine Heartworm Disease. In most cases, there will be no signs seen in heartworm infected dogs. However, for the patients who do elicit signs; the most common one seen is coughing. Other major signs can include weight loss, exercise intolerance, difficulty in breathing and even ascites (fluid accumulation within the abdominal region).

If your dog displays any of the fore-mentioned signs, it is highly recommended that you bring him or her to your veterinarian immediately. Your vet may wish to conduct a few tests in order to confirm if your dog has heartworm disease. The most common test performed is called a Heartworm Antigen Test. This test detects the adult, female worms present in the heart. Another known test is called the Filter or Modified Knott’s Test, which helps to detect specific organisms, known as microfilariae. He or she may also wish to perform chest radiographs or an echocardiogram, depending on the severity of each individual patient’s case.

The main protocol towards treatment of Heartworm Disease consists of three factors. A drug known as Melarsomine is normally administered in three doses. The first two are given 24 hours apart, while the third one is given 1 – 3 months later. Exercise restriction plays a significant role in the health management of a patient with this disease. It is especially recommended for 4 – 6 weeks after every dose of Melarsomine is given. Other medications, such as Prednisone or NSAIDS can also be considered in order to aid with decreasing any inflammation seen around the injection site.

Before the worms enter into their adult stage, a preadulticide treatment plan can also be given for 1 – 3 months. This includes the recommended medication of Doxycycline, which kills a specific bacteria known as Wolbachia. This bacteria is known to live within the immature stages of an adult worm. Monthly heartworm preventatives can also be given as a precautionary step towards avoiding this disease in your pet.

When dogs with heartworm disease become severely infected, they can develop another condition known as Caval Syndrome. This disease displays a sudden onset of signs, which include severe lethargy, pale coloration, weakness and difficulty in breathing. This condition is taken as a medical emergency. Its treatment involves surgical removal of the worms; otherwise, the patient can deteriorate very quickly.



Dr. H. Bhullar DVM

Dr. Sifti Bhullar, DVM