Canine Heartworm Treatment Through Immiticide®: Assessing the Risks

Canine heartworm treatment is a risky business. Treatment is difficult and the complications can be severe. Many dogs don't survive treatment for canine heartworm.

Treatment Options for Canine Heartworm

Merial's Immiticide®, which contains the drug melarsomine, is the only medication currently labeled for the treatment of adult heartworms in dogs. Melarsomine is an arsenic-based compound that's injected into your dog's lumbar muscle. There are two treatment protocols for the use of Immiticide®.

The first option is to administer a series of two injections, 24 hours apart. The second involves three injections; the second injection should be given 30 days after the first, and the third 24 hours after the second.

Risks of Melarsomine Treatment for Canine Heartworm

Because melarsomine is an arsenic-based compound, it could protentially poison your dog.

One of the most common complications in treatment of canine heartworm is the damage caused to lung tissue when dead adult heartworms accumulate in the lungs. This complication is serious and is treated with strict restriction of movement.

Of course, there also remains the chance that melarsomine treatment won't kill all adult heartworms, leading to later reinfection. If this happens, your dog will need to be treated again, leading to increased risk of arsenic poisoning as well as submitting him, once again, to the danger of lung embolism.

If your dog's heartworm disease is particularly severe, your vet may want to treat your dog with an ivermectin-based heartworm medication, to kill immature worms before beginning the melarsomine treatment to remove adult heartworms.

Ivermectin Will Kill Larvae, Not Adult Heartworms

Some dogs may not be good candidates for treatment with melarsomine. These dogs can be placed on a monthly dose of ivermectin-based heartworm preventative medicine. However, though ivermectin does kill the larvae and shorten the lifespan of adult worms, while sterlizing them, it doesn't kill the adult heartworms.