Emily currently lives in Austin TX and spends most of her time writing and enjoying the weather. She loves to write stories for children and screenplays for all ages. When she's not writing, Emily is teaching horseback riding, working as a vet tech, or painting. Many pet owners know that their dog or cat needs to be on heartworm preventative but few really understand these strange parasites and why it’s so important to prevent against infestation.
Many pet owners know that their dog or cat needs to be on heartworm preventative but few really understand these strange parasites and why it’s so important to prevent against infestation.
Heartworms are parasites that obey their label: they are worms that infest the heart. Although they are microscopic worms (microfilaria) in their younger stages of life, they can grow up to 14 inches long when attached to your animal’s heart and cause major heart conditions, liver and kidney damage, and eventually cause death.
How do dogs and cats get heartworm? The tiny microfilaria are carried between animals via mosquitoes. One mosquito bites a dog that has heartworms, sucks in the tiny microfilaria that were spawned by the adult heartworms in the heart, and flies off to bite another animal. While the mosquito sucks in blood from the next dog or cat, the microscopic worms swim down into the bloodstream and migrate to the heart. When they reach their target organ they latch on and begin to grow, disrupting the heartbeat and eventually causing visible symptoms such as lethargy, fatigue, coughing, and eventual heart murmurs.
Dogs are the preferred host, but heartworms have been known to kill cats. They do not, however, infect humans as our bodies are not ideal environments for their reproductive or feeding cycles. Keep in mind that cats, despite not being the preferred host for these parasites, need fewer adult worms to cause serious damage.
Heartworms take up to six months to be detected via a simple blood test. This means that puppies and kittens, although they are too young to be tested, can still go on monthly preventatives. Once they turn six months of age, however, they should be tested annually to verify that they are negative and able to take monthly preventative.
If an animal is positive, he or she can be treated depending on the severity of the case. In past decades heartworm treatment was invasive and dangerous ranging from arsenic injections to open heart surgery in order to kill and remove worms. Current treatment is confined to a series of injections in the muscles of the back over a period of 48 hours followed by six to eight weeks of inactivity to allow the body to purge the dead worms. The cost of this treatment varies, but, in general, it’s far less expensive to prevent heartworms than it is to treat them.
Some cases of heartworms cannot be treated if the animal has been infested for a long time and shows many of the symptoms. For this reason, early detection is necessary in order to treat animals who are positive for heartworms.
Administering heartworm preventative to an animal that has not been tested is risky and dangerous. Owners can cause serious medical problems if they administer preventative medicine to a dog that is positive for heartworms. For this reason, heartworm medication is only sold through veterinarians.
Risk factors and prevention are dependant upon where you live. In Texas, for example, veterinarians suggest that owners keep their dogs on heartworm preventative throughout the year due to warm weather conditions. Veterinarians in Alaska may suggest that dogs stay on preventative for shorter times and only during warmer months.
There are many different kinds of preventatives ranging from oral (Heartguard and Interceptor) to topical (Revolution) and your choice depends on your needs. Collie breeds and some Shepherds need to take ivermectin-free products (like Interceptor) due to genetically based allergic reactions to ivermectin, a common ingredient in heartworm preventatives. Pro-Heart, an popular injectible heartworm preventative, was taken off the market due to health concerns.
Although many heartworm preventatives help prevent against other parasites like hookworms and roundworms, the Center for Disease Control (CDC) still recommends annual dewormers for dogs and outdoor cats. Dewormers for intestinal parasites helps rid your animal of many different kinds of worms and keeps your family safe from any intestinal parasites that may be transmitted from your pet.
Consult your veterinarian with any questions or concerns about your pet or recommended prevention against heartworms.