Heartworm Disease In Dogs

Canine heartworm disease, caused by the filarial nematode Dirofilaria immitis, was first reported in India in 1980 and also affects cats. Adult dogs aged between 4 and 8 years are more commonly affected by this fatal parasitic infection, which is transmitted by mosquito bites from Anopheles and Culex species.


Affected pets exhibit symptoms such as soft cough, difficulty in breathing, frothy discharge from the mouth, weight loss, liver dysfunction, heart enlargement, emaciation, and ascites with edema in the abdomen and limbs. In most cases, appetite remains normal, but sudden anorexia, pale mucosa, and severe weakness may also be present. The color of the urine may also be dark brown.

Heartworm Disease In Dogs
Heartworm Disease In Dogs


A diagnosis of heartworm disease can be made based on the animal’s history, chest X-rays, auscultation, and examination of blood smears under a microscope to identify the microfilariae. Haematological tests can reveal an increased eosinophil count by 7-16% and elevated ESR.


Levamisole hydrochloride and Thiacetarsamide sodium are effective drugs for eliminating adult parasites. TSS is given intravenously at a dose rate of 2 mg/kg twice a day for 2 days, one hour after feeding the dog each time. The dog should be given complete rest for the first two weeks.

To eliminate microfilariae, Dithiazanine Iodide (Dizen) is administered orally at a dose rate of 6.5 mg/kg body weight once a day for 7 days during or immediately after feeding the pet its scheduled diet. This drug should be given 6 weeks after administration of filaramide or arsenamide to improve the pet’s physical condition and avoid toxic effects of the drug.
Contact Dr.C.M.’s Pet Clinic, South Bopal, Ahmedabad if your pet have the symptoms as listed above.