Dogs And Heartworms

Heartworms are a parasite found in dogs which are spread by mosquitoes. It is a very serious disease and, left untreated, can kill your dog.

At one time heartworms were only found in parts of the United States with mosquito problems but in the last 30 years they have spread to all of the lower 48 states. There is no part of the continental U.S. that is free of heartworms. Unless your dog takes a regular heartworm preventive of some kind he is at risk of developing heartworms after being bitten by a mosquito.

The basic heartworm life cycle is fairly simple. A mosquito carrying heartworm larvae bites your dog and transfers them into your dog’s bloodstream. There they will incubate for a few days until they migrate to your dog’s heart. At that point the microscopic larvae will begin to grow in your dog’s heart until they become very large. They can interfere with your dog’s heart action and pieces of the heartworms can break off which can also cause problems. The heartworms will also continue to reproduce.

Your dog probably won’t show any symptoms of having heartworms until the later stages of the disease. At that point the first symptom is usually coughing. This means that the heartworms have migrated to your dog’s lungs. They will usually be found in the veins and blood vessels leading to the lungs as well. They can also be found in your dog’s liver. From there they will infest other organs, along with your dog’s heart. As they infest organs the organs will begin to stop functioning and your dog will die. Your dog probably won’t be able to tolerate any exercise long before he starts showing any definite symptoms because he will be feeling weak and lethargic.

Fortunately, heartworm disease is easily preventable. There are a number of heartworm preventives in the market such as Heartgard, Interceptor, Revolution, Sentinel, Iverhart, and Ivermectin. Some preventives are given as monthly treats while others are daily pills. There are even long-terms injections available for your pet from your veterinarian. If you give your pet a regular preventive then there is no need for him to ever get heartworms.

In the United States heartworm medication requires a veterinary prescription. Your vet will recommend a test for heartworms before writing the prescription. This is a simple test that draws your dog blood and checks for the presence of heartworm microfilariae in the blood. If your dog’s blood is clear of the presence of heartworms then your vet will write the prescription. If there is any sign of heartworms then your dog will need treatment.

Treatment for heartworms usually takes two forms. There is a quick approach and a slower approach. The quick approach uses an injectable drug to kill the adult heartworms. It is given over the course of two days. It kills the adult heartworms in the dog’s heart and the surrounding blood vessels. There is some risk involved in this approach since the large heartworms will be breaking off and may cause blood clots. When the heartworms break up they are carried to the lungs where they lodge in the tiny blood vessels. They are eventually reabsorbed by the body but it is possible that your dog could have a bad reaction at this time while the heartworms are in the process of dying. Your dog will probably cough during this time and for the next seven or eight weeks.

There is a second, slower form of treatment that involves using the same chemical that is found in heartworm preventive. It kills off the young heartworms as they emerge and allows the older ones to simply die off. This does take a long time and you won’t see a dramatic improvement in your dog. However, it is less risky.

The best way to combat heartworms is to start your dog on heartworm prevention as soon as you get him. Even very young puppies can take heartworm preventive. If you keep your dog on heartworm prevention for his whole life then you’ll never have to worry about heartworms.

Heartworm season is on the way so be sure and get your dog tested and on preventative, you will be glad you did. We keep our dogs on preventative 12 month of the year just to be safe.