Heartworm Disease in Dogs: Treatment

Heartworm disease in dogs is potentially life threatening as it can cause permanent scarring ofHeartworm Disease in Dogs: Treatment the lungs and heart failure if left untreated.  Once the diagnosis of heartworm disease is made, and your vet has evaluated your dog and determined that treatment is safe, there are a few treatment options that you and your vet can choose from.

Heartworm Treatment: Treating Heartworm Infection in Dogs

Heartworm treatment in dogs is aimed at killing the adult worms along with the immature worms and circulating larval stages.  This requires a combination of treatments which may take months to complete.
Killing the adult worms is usually performed using two to three injections of melarsomine, which are given one month apart. The injections are given deep into the muscles along the dog’s spine and can result in pain at the injection sites. Melarsomine does not kill worms less than 4 months old, so sometimes the treatment is put off for a few months until the young worms mature to the point that they can be killed by melarsomine.
Once the diagnosis of heartworm infection has been made, dogs are started on monthly heartworm preventatives which kill some of the larval stages as well as microfilaria. In addition to killing these larval worms, heartworm preventatives (products which contain ivermectin, milbemycin oxime, moxidectin or selamectin), when given for two to three months prior to melarsomine, have been shown to decrease the worm burden, decrease the fertility of the female worms, and lessen the post-treatment complications discussed below.
Another part of heartworm treatment involves giving antibiotics. There  is a bacteria which lives inside the worm called Wolbachia.  These bacteria can be killed by administering oral antibiotics (Doxycycline) for a month prior to Melarsomine administration.

Heartworm Treatment: Alternative Therapy for Heartworm Disease

Injectable heartworm treatment is not for every dog. If a dog is too old or treatment will cause an owner financial hardship, owners may elect to place the dog on long-term monthly heartworm preventative medication which will kill the majority of worms within two years. It is important to note that these dogs cannot be exercised during this long treatment period. Oral Doxycycline should be used every 3 to 4 months during this period as well.

Heartworm Treatment: The Risk of Treating Heartworm Disease

Heartworm treatment is not without complications, the main one being pulmonary thromboembolism where dead worms decompose and pieces of them get stuck in the blood vessels in the lungs. These dead worm pieces cause inflammation, block blood flow, and result in thromboembolism. Signs of pulmonary thromboembolism include difficulty breathing, coughing up blood, or fever. These signs are usually seen within the first week or two after treatment, but may be seen up to a month later. Treated dogs need to be kept quiet and calm for at least 4 weeks after each melarsomine injection to help minimize the risk of thromboembolism.

Click here to learn more about the life cycle of the heartworm.

Speak Your Mind