April is Heartworm Awareness Month. Heartworm is a preventable disease spread by mosquitoes. Left untreated, it can cause permanent damage and death. But prevention is affordable and easy. Here are eight things you should know to protect your pet.

1. Heartworm can kill your pet. Heartworm is caused by a parasitic worm called Dirofilaria immitis that enters your pet’s body after an infected mosquito bites your pet. Worm larvae left by the infected mosquito-spread through your pet’s bloodstream and migrate to your pet’s heart and surrounding arteries. The worms take 5 to 7 months to mature. Female worms are about the size of spaghetti noodles (up to 14” long) and produce millions of offspring that live in your pet’s bloodstream. Hundreds of adult worms can live inside an infected pet. As worms clog your pet’s heart and blood vessels, they block proper circulation and can lead to lung damage, organ failure, and death.

2. Texas is one of the top 10 states with the highest rates of Heartworm. Every three years the American Heartworm Society gathers data from thousands of veterinary clinics across the country to track the spread of Heartworm. Texas consistently ranks among the top 10 states with the highest rates of Heartworm infection. In 2019, the most recent year the study was performed, Texas clinics participating in the study reported 100 cases or more of Heartworm, compared to fewer than 5 cases reported by clinics in areas such as North Dakota. Both the American Heartworm Society and the Companion Animal Parasite Council rank Texas as a zone for extremely high rates of Heartworm.

3. Signs of heartworm include lethargy, shortness of breath, and fatigue. In the early stages of Heartworm, there are few symptoms. As the worms grow in size and number, your pet may develop a cough, become short of breath, grow lethargic, lose its appetite and lose weight. By the time your pet develops symptoms, the disease may have already caused permanent damage to your pet’s heart and organs.

4. Heartworm can infect cats. It is rarer for Heartworm larvae to grow to maturity in cats, but once they do, there is no treatment for cats with Heartworms. Cats cannot be treated with the same medication used for dogs, so the only protection for cats is prevention.

5. It costs less than $8 a month to prevent Heartworm. Heartworm prevention often takes the form of chewable tablets that you give your pet once a month. Tablets from Spay Neuter Network cost $30 for a 6-month supply for dogs less than 25 pounds ($5 a month). The cost is $35 for a 6-month supply for dogs that are 26 to 50 pounds and $45 for dogs over 50 pounds. The cost for a full year of prevention is even cheaper.

6. It costs $500 to $1,000 or more to treat Heartworm. If your pet gets infected with Heartworms, treatment is costly, complicated, and lengthy. The exact cost of treating Heartworm depends on the size of your dog and the stage of the disease. Before treatment, your pet may need x-rays, blood tests, and an echocardiogram to determine how much damage the disease has already caused your pet’s body. Treatment starts with a combination of medicines taken orally, including prevention medication and medication to minimize a negative reaction later when the worms begin dying in your pet’s body. After taking these medicines for several months, your pet will get its first injection of melarsomine to kill the adult Heartworms. Thirty (30) days after the first injection, your pet will need a 2nd injection. Twenty-four (24) hours after the 2nd injection, your pet will need a third injection. During treatment, your pet cannot exercise. No jumping, playing, or running. Pets need to stay as calm as possible during this period because the dying worms are getting dislodged from your pet’s heart and surrounding arteries. As they travel through your pet’s blood vessels, exertion can cause these worms to lodge in other arteries, especially those in your pet’s lungs, causing a pulmonary blockage that can lead to shock and death. Injections are given deep into your pet’s muscles and may cause pain. Your vet may prescribe pain medication. Depending on your pet’s age and health and the severity of its Heartworm disease, your vet may also recommend that your pet stays at the clinic overnight after injection in case of a negative reaction. It is much easier and far less costly to prevent Heartworm than it is to treat it.

7. Heartworm prevention keeps your pet healthy in other ways. Most kinds of Heartworm medication also prevent other worms. Currently, the Heartworm prevention tablets provided at Spay Neuter Network also prevent two kinds of roundworm (oxocara canis, Toxascaris leonina) and three kinds of hookworm (Ancylostoma caninum, Uncinaria stenocephala, Ancylostoma braziliense).

8. Start prevention early. Puppies and kittens can get bitten by an infected mosquito as soon as they are born. The American Heartworm Society recommends that you start giving your puppy or kitten prevention medication when they are 8 weeks old. Giving your pet Heartworm prevention medication once a month is the safest, easiest, and most affordable way to protect your pet from a preventable disease that can cause lasting damage and death.