How to Kill Heartworms

Killing heartworms in dogs requires intramuscular injections from a veterinarian.

Heartworm, or Dirofilaria immitis, is transmitted to a dog when an infected mosquito bites it. The larvae, called microfilariae, enter the bloodstream and eventually infect the heart. Left untreated, heartworm can cause heart, lung and kidney disruptions and even death from sudden heart failure. Preventative medicine ensures that the animal does not contract heartworm; however, adulticides are necessary to kill adult heartworms. (See References 1)

Things You'll Need

• Heartworm tests
• Melarsomine dihydrochloride treatments

Instructions

1. Take the dog to a veterinarian for testing. The veterinarian may conduct a blood test to detect circulating microfilariae; but, according to the American Heartworm Society, 15 to 20 percent of positive dogs will not exhibit circulating microfilariae. An antigen test is more accurate; it detects proteins released by adult female heartworms. However, dogs can become infected with only male adult heartworms. In this case, the veterinarian may conduct an antibody test, chest x-ray or ultrasound.

2. Schedule a veterinary appointment for the dog to receive intramuscular injections of melarsomine dihydrochloride (an adulticide). According to Pet Education.com, treatment depends on the severity of the infection. In less severe cases, the dog may be treated with a preventative for 1 to 4 months to kill any migrating larvae before treating with melarsomine dihydrochloride.

3. Monitor the dog's condition carefully after treatment. Keep the dog quiet, with cage rest and limited exercise, during treatment and for at least 4 months afterwards. Watch for signs of fever, rasping and excessive coughing. When the heartworms die, they move through the blood vessels and may cause blockages in the lungs, called pulmonary embolisms.

4. Schedule follow-up appointments as recommended by your veterinarian. The veterinarian will most likely do an antigen test to determine if the infection has cleared. It may take a month or longer after treatment for the heartworms to die. In addition, according to the Heartworm Society, dogs that test positive 4 months after treatment should be retested 2 to 3 months later and receive another treatment of melarsomine dihydrochloride, if necessary.

Tips & Warnings

• Use pet-friendly mosquito repellents on the dog and keep your yard free of standing water to reduce the dog's exposure to heartworm-carrying mosquitoes.

• According to the American Heartworm Society, a type of cardiovascular collapse, called caval syndrome, can result in sudden death when heartworms block blood flow. Symptoms include labored breathing, pale gums and dark urine. Immediate surgery is needed to save the dog.

References

• PetEducation.com: Heartworm (Dirofilaria Immitis) Infection & Prevention in Dogs; Holly Nash, DVM, MS
• American Heartworm Society: Frequently Asked Questions

Resources

• The Dog Health Guide: Heartworm in Dogs
• Companion Animal Parasite Council: Heartworms in Dogs