Treatment of Canine Heartworm Disease

Treatment consists of two parts -- totally taking about 2 months. During these two months, the dog should be kept fairly well confined to try and prevent any large mass of dying adults or immature heartworms from leaving the heart and large vessels at a single time. If this should occur, the mass could block a major vessel and cause sudden death.

First: Medication is given to kill the adult heartworms. This medication is an arsenic product. Two injections are given 24 hours apart in the muscle of the back. Although the medication used now is considered "safer" than the older intravenous arsenic injections, there is still possibility or reaction to the medication. For this reason, we recommend 48 hours of hospitalization during this stage of treatment. Often there is swelling and discomfort at the site of injection. If this occurs, anti-inflammatory medication can be used. Barring any untoward reaction during this part of the treatment, the dog is discharged for one month during which time he should be confined and discouraged from any hard play or exercise.

Second: One month after the adult heartworms are treated the microfilaria need to be attacked. This requires a one day hospital stay. Oral medication is given and , again, the dog is watched for any reaction. The concern, again, is that there may be an initial reaction as the baby heartworms start to die. If all goes well, the dog may go home that evening and continue his enforced "rest" for another month.

After another month passes, the patient must be checked for heartworms to be sure that all the adults and all the microfilaria have been killed. In some cases it will take up to 6 months for all of the adult heartworms to be eliminated from the patient. Heartworm preventative is continued for the life of the patient.

After seeing what is involved in treatment, wouldn't it be better to prevent the problem in the first place? We recommend year-round heartworm prevention.

Preventative Products

Although daily heartworm preventative products are still available, they have been replaced, in large part, by monthly medication that can be administered orally or topically. Before starting any heartworm preventative program, have your dog tested to be sure he's not already a heartworm patient. The Heartworm Society recommends regular heartworm testing even if your dog is maintained on year round preventative.

Canine Heartworm Disease | Canine Heartworm Lifecycle | Canine Heartworm Treatment
Feline Hearworm Disease | Feline Heartworm Lifecycle
Heartworms in the USA | Preventative Comparisons