Canine Heartworm Treatment Options

Heartworms are a parasite that are transmitted to dogs by mosquitoes. If a dog is bit by an infected mosquito, the heartworm larvae are transmitted directly into the bloodstream. Heartworm disease can be deadly. Luckily, there are treatment options available.

  1. Symptoms and Prevention

    • Unfortunately, dogs with heartworms do not usually show any symptoms until the condition has become very advanced. Symptoms include coughing, difficulty breathing, lethargy and a dull coat. The dog may even have abdomen swelling and fainting spells. Heartworms can affect more than just your dog's heart; they can invade the lungs and cause problems with your dog's veins and liver.

      There are preventative treatments available. Talk to your veterinarian about this if you are concerned about your dog getting heartworms; he can prescribe a medication, such as Heartgard, that can be given regularly throughout the year.

      If your dog has heartworms, it is important to work closely with your veterinarian to determine the best course of treatment. This condition can lead to heart failure and should be taken very seriously.

    Immature Worms

    • In most cases, the first step to treating heartworms will be to begin killing immature worms. This is necessary because if you first begin killing adult worms, the others will continue to mature. Your vet is likely to prescribe an ivermectin-based medication for your dog to begin with. This is the same thing that is used in heartworm prevention. Another option is a milbemycin-based medication; however, this will kill the immature worms very quickly, which may shock your dog's system.

      Your dog will likely need to stay on this first step of treatment for up to three months before attempting to treat the adult worms. Work with your veterinarian to determine how long you should wait before treating the adult worms; if they are a serious and immediate issue, she may suggest you not wait as long.

    Adult Worms

    • The next course of action is to kill the adult worms. The only medication used for this purpose is called melarsomine dihydrochloride, and is given in two or three doses in order to kill of the worms. If your dog has a lot of worms or if your veterinarian is worried about circulatory shock, three doses will probably be used. This will prevent a high number of worms being killed all at once, and will be easier on your dog's system.

      This treatment is administered to your dog by an injection in its lower back muscles. It is a painful procedure and your dog may be sore afterward; your vet may even prescribe pain medication for your dog to help it through this treatment. After the injection, your dog will need to be confined and monitored closely for approximately one month. You must notify your vet immediately if your dog experiences nosebleeds, coughing or develops a fever.

      If you cannot afford the melarsomine dihydrochloride treatments̵2;which are expensive̵2;you can opt to use the ivermectin-based medication instead. However, it will not kill the adult heartworms. It may shorten their lifespan and sterilize them, though, and prevent the immature worms from maturing.

    Precautions

    • If you have a collie or other herding dog breed, talk to your veterinarian to see what sources of treatment are safe to use. Ivermectin-based medicines can be toxic to these breeds. However, according to Mike Richards, D.V.M., the amount of ivermectin necessary to become toxic is usually higher than the amount that is usually found in heartworm prevention and treatment products, such as Heartgard.

      It is important to work closely with your veterinarian to determine the severity of your dog's heartworms and how that will affect the dog's treatment. In some advanced cases of heartworm disease, dogs should not receive melarsomine dihydrochloride.