Heartworms in dogs have been diagnosed in all 50 states, but if you live in the Southern portion of the United States your dog is at high risk for this preventable disease. Dr. Anna Coffin discusses the basics of heartworm disease and heartworm medication available.
Heartworms are actual worms that live in a dog’s heart. The adult heartworm is about 12 inches long. They are transmitted from dog to dog by mosquitoes. Once the mosquito injects the larvae under the skin, it takes six months to mature into an adult worm and reach the heart. Dr. Anna Coffin diagnosis approximately 30 cases every year. [Tweet “Heartworms are actual worms that live in a dog’s heart. The adult heartworm is about 12 inches long.”]
- Weight loss
- Exercise intolerance
Diagnosis of heartworms is made with a blood test. Most of these blood test can be performed in the veterinary clinic and take eight to ten minutes to complete. These tests detect the adult worm in the heart. A blood smear can also be evaluated for microfilaria (baby heartworms). Dr. Anna Coffin recommends heartworm testing every year even if your dog is on heartworm prevention all year around.
Heartworms are preventable with the routine use of heartworm medication. Heartworm medications are available as tablets, topical, and one six-month injectable. Missing one single dose of heartworm medication can put your dog at risk for getting heartworms.
1. Ivermectin: This is the most common heartworm medication available. This heartworm medication is a chewable tablet that must be given every 30 days. Heartgard, Iverhart, and Tri-Heart are examples of this type of heartworm medication.
2. Milbemycin oxime: This heartworm medication is also a chewable tablet that must be given every 30 days. Interceptor, Sentinel, and Trifexis are examples of this type of heartworm medication.
3. Moxidectin: This heartworm medication is available as a topical product called Advantage Multi and needs to be administered every 30 days. ProHeart 6 is another example of this type of heartworm medication. It is unique in that it is an injection that protects your dog for six months.
4. Selmectin: This heartworm medication is available as a topical product called Revolution. It needs to be administered every 30 days. This product also treats fleas, ear mites, Sarcoptic mange and a few intestinal parasites.
Recent studies have found a strain of heartworms that is resistant to heartworm medication. To prevent further resistant strains, it is important to test annually and treat adult heartworms immediately.
The goal of heartworm treatment is to eliminate adult heartworms that cause disease and eliminate microfilaria that is infectious to mosquitoes that then transmit the disease to other dogs.
Immiticide (melarsomine) is the heartworm medication that kills the adult heartworms. It is fifteen times more expensive to treat adult heartworms than it is to prevent.