Heartworm Treatment


These guidelines have been provided by the UF College of Veterinary Medicine’s Community Outreach Medicine program, which provides treatment for all heartworm positive Plenty of Pit Bulls rescue dogs.  Please read carefully and follow instructions — your foster dog’s life depends on it!

Heartworms are transmitted by the bite of a mosquito. The parasite moves from the bite into the dog’s tissue. As they grow and reproduce they are released into the blood stream and eventually occupy the heart. If left untreated, heartworm disease can reduce the dog’s quality of life, result in congestive heart failure, and ultimately lead to death.

Most of our adoptables are treated for heartworms using Immiticide (melarsomine dihydrochloride), which is also called the “fast kill” method. The Immiticide is administered by deep intramuscular injection in the epaxial (lumbar) muscles.

Our clinic follows the American Heartworm Society’s recommendation of three injections, with the second treatment exactly one month after the first, and the third twenty-four hours later. All dogs are given an NSAID (non-steroidal anti-inflammatory) before each treatment to ease any discomfort that may be associated with the injection.

After a dog has started immiticide treatment it is critical you follow these guidelines from the American Heartworm Society:

  • Let the veterinarian know ahead of time if the dog is on any medications.
  • Do not administer any medication or NSAID without consulting the veterinarian conducting the treatment.
  • Exercise restriction should be rigidly enforced from the time of diagnosis through the period of treatment and recovery. Most dogs will need to be cage rested and leash walked only.
  • No rough play, jumping, or running should be allowed at any time.
  • Leash walks should be kept short and easy on the dog.
  • Some dogs experience a temporary lack of appetite, vomiting, congestion, depression/lethargy, drooling, panting, or coughing/gagging. If any of these symptoms last more than 24 hours please contact your rescue group to get the dog examined by a veterinarian.
  • If the dog begins coughing up blood or collapses, contact your rescue group immediately and take the dog to the emergency hospital.
  • Continue to administer Heartgard or Iverheart on a monthly basis.
  • After the last injection is administered, exercise restriction should be continued for 6-8 weeks (Typically when the hair has grown back over the injection sites).

The American Heartworm Society has approved another treatment for heartworm, called “slow kill.”  This involves monthly doses of an ivermectin-based heartworm preventative (e.g., Heartguard) and alternating doses of minocycline.  This can be a good alternative for some dogs, depending on their health and home situation.

Regardless of treatment options, all dogs diagnosed with heartworm disease need to follow exercise restrictions.  Heartworm is a serious and life threatening illness.

For more information, please read these guidelines from the vet school:  Clinic-Information-Sheet