Horse Wormer to Prevent Heartworms in Dogs

Ivermectin is a safe and effective dewormer used in horses. It was first introduced into veterinary medicine in the 1980's and is still being used today to treat horses for a wide variety of parasitic infections including strongyles, pinworms, ascarids, stomach worms, bots and many more. Ivermectin works by paralyzing the invertebrate animal through the interruption of specific neurotransmitter chemicals. It is has been proven safe in horses at up to 9 times the therapeutic dosage.

  1. Uses

    • Ivermectin has also been shown to be particularly effective when used in dogs to prevent heartworm infection. When administered as a once a month tablet, the medication kills any infective heartworm larvae that enters the bloodstream before it can migrate into the heart and develop into mature heartworms. Dogs have shown to have a 99 percent rate of resistance to infection when regularly treated with oral ivermectin.

    Heartworm Treatment

    • Ivermectin is also administered to dogs after adulticide treatment for heartworm disease to kill any remaining microfilarae, or immature heartworm larvae, to prevent re-infection. Microfilarae are common in dogs that have experienced heartworm infection and the presence of the larvae can be detected through a microscopic examination of a blood sample. Ivermectin is administered orally after the dog has been given medications designed to kill the adults.

    Dosages

    • Common dosages of ivermectin given to dogs to prevent heartworm disease are .0015 to .003mg per pound of body weight once per month. A regimen of .1mg per pound of body weight is given to dogs to kill microfilarae.

    Side Effects

    • Giving ivermectin to heartworm positive dogs that have not been treated with an adulticide can result in death due to toxicity. Collies and Shetland Sheepdogs should not be treated with ivermectin as both breeds are genetically predisposed to toxicity and death. Other common side effects of using ivermectin include disorientation, weakness, blindness, tremors and stumbling.

    Duration of Treatment and Prognosis

    • The duration of treatment with ivermectin varies based on the severity of the microfilarae infection. Repeat microscopic blood examinations will determine whether or not live microfilarae exist. The prognosis for dogs receiving ivermectin for microfilarea infection is good. Dogs that take ivermectin for heartworm prevention will take the drug for the duration of their lives.