Heartworm Disease

Heartworm Disease in Pets

Heartworm disease is a serious disease that can be spread from host to host by the bite of an infected mosquito. It is a parasitic roundworm that affects a variety of animals and is reported in all states of the U.S.  This disease can cause lung damage, heart failure, or other organ damage and death in pets. Dogs cannot spread heartworm to one another or their owners through contact.  Heartworms are only spread via mosquito bites.

Transmission

The mosquito is a transitory host, meaning that the worms are only in the mosquito for a short period and do not develop there. Dogs are natural hosts for heartworms. When an infected mosquito bites a dog, the worms will enter the bloodstream and mature into adults, mate, and produce offspring. They are called heartworms because the adults live inside the heart, lungs, and blood vessels of an infected animal.

Signs and Symptoms

When an infected mosquito bites a dog, it spreads the infected heartworm larva. The larva then takes about 6-7 months to grow into the adult stage.  The infected animal will not begin to show signs of the diseases until the worm has grown into an adult. The heartworm must be present in the animal for six months to a year before it shows up on a heartworm test. As the disease grows, dogs may show signs by having a persistent cough, fatigue, decreased appetite, and weight loss. These parasitic worms cause immense damage to the internal organs as they grow and reproduce.  At an advanced stage, the worms cause Caval Syndrome (a mass of worms blocks the blood flowing back to the heart) and cause death from heart failure. Adult heartworms grow a foot long and look like spaghetti and can live up to seven years.

Treatment and Prevention

You can help prevent your furry friends from getting heartworms by giving them monthly heartworm prevention medication. This prevents the heartworms from maturing to the adult stage, during which they cause most of the internal damage.  There are a few types available such as monthly chewable, monthly topic solutions, and injections. However, if your dog acquires heartworms, there is treatment available. The FDA has approved injections that kill heartworms. Dogs should be tested annually for heartworms.

What about cats?

Cats CAN also get heartworm after being bitten by an infected mosquito. Heartworms can be fatal to cats, butin general heat worms  do not thrive in their bodies. Whereas dogs can have up to 250 adult heartworms living inside of them, cats may only develop 1 or 2. Cats generally show mild heartworm symptoms. However, a small number of heartworms can cause considerable damage. A blood test is needed to confirm whether heartworms are present. There is currently no preventative treatment for heartworms available for cats, so the symptoms are treated with medication. As with their canine friends, there are monthly tablets and topical solutions available to prevent heartworms. These are typically given monthly, along with a flea and tick preventative.