Heartworm infections are found anywhere mosquitos are common. In this blog, we hope to inform you about mosquitoes and heartworms and why prevention is so Important to our Texas pets. Heartworm disease is easy to prevent but difficult to treat. With most cases found within 300 miles of the U.S. coastal regions from New Jersey to Texas, the American Veterinary Medical Association estimates that approximately 25% of dogs in this country carry the disease. This is why we would like to inform you about mosquitos and heartworms and why prevention is so important to our Texas pets.
What Are Heartworms?
Mosquitos transmit canine heartworms from dog to dog. When a female mosquito bites an infected dog, the larvae of the heartworm contaminate the mosquito’s saliva and infect the pest’s body. The larvae develop in the mosquito and are then injected into the skin of another dog. This is where they develop and progress into the bloodstream. The worms survive by receiving nutrients from your dog’s blood. This allows them to grow, eventually settle in your dog’s blood vessels.
When the worms reach full maturity, they migrate to your pet’s pulmonary artery, where they cause extensive damage. This damage includes weakening the lining of the artery and increasing blood pressure. It also causes right-sided heart enlargement, leading to cardiac dysfunction and disease.
These serious consequences are why we would like to inform you about mosquitos and heartworms and why prevention is so important to our Texas pets.
Can My Cat Get Heartworms?
The rate of heartworm disease in unprotected cats that have not received preventative medication is significantly lower than that of unprotected dogs. Outdoor cats are at an increased risk of contraction and are twice as likely to contract heartworm disease than indoor cats.
Like canine heartworms, feline larvae migrate and mature, ending up in the right side of the heart and the pulmonary arteries of your infected cat. They develop into adult heartworms capable of reproduction about six months after they enter the cat. At around six or more months after infection, the adult worms produce a new type of larvae that will live in the cat’s blood. In response, the cat’s body creates natural antibodies take over to attempt to destroy the parasites. Some good news is that cats are considered “resistant hosts,” and few circulating worms are generally found during diagnosis.
Symptoms of Heartworm Disease
The scary thing about heartworm disease is that your dog may not show any symptoms until the disease is far advanced. It usually takes about seven years from infection for canine heartworm larva to grow in the artery to create problems. At this point, the disease is difficult to cure.
Dogs with the heartworm parasite usually show all the signs of an animal with advanced heart disease. These symptoms include: exercise intolerance, coughing after exertion, and susceptibility to lung problems. In addition, severely sick dogs will show expanded bellies from fluid build-up and can cough up blood. They may also be anorexic due to the inability to eat or refusing food. Without treatment, the heart will be unable to function, and your pet may pass from congestive heart failure.
One of the most challenging aspects of diagnosing feline heartworm disease is that there are no specific clinical signs. Signs of chronic heartworm infestation in cats include: coughing, labored raspy breathing, vomiting, lethargy, weight loss, and chylothorax (fluid around the lungs).
How Does My Vet Diagnose Heartworm Disease?
At this time, there are no specific tests that can diagnose heartworm disease in cats. A variety of tests may be done to aid diagnosis. This includes urine analysis, heartworm antigen and antibody tests, x-rays which may reveal the enlargement of certain veins or arteries, and an electrocardiograph (ECG), which may allow for the identification of worms in the heart or pulmonary artery. An ECG can also exclude or confirm other heart diseases that may exhibit similar symptoms.
For dogs, your veterinarian diagnoses heartworms in your dog in several ways. The first way is to take a small drop of blood and place it under a microscope. If the larvae are large enough, the vet can see them moving in the blood serum. The second way is called a “snap” test. A small drop of blood is mixed with an anti-coagulant then dropped onto a reagent strip. The canister is snapped closed and the chemical reaction occurring determines whether heartworm is detected in their blood. Another diagnostic test requires the blood to be filtered through a fine mesh. This removes the worms, which can then be seen under a microscope.
Heartworm Disease Treatment
Treatment of canine heartworm disease involves injecting your pet with Immiticide®. This is injected in the lower muscles of the back twice. This kills the adult worms, causing them to disintegrate and pass out of your dog’s body. The injections are quite painful, and most vets will also recommend giving your dog painkillers and steroids to alleviate the discomfort. For lighter infestations, some veterinarians prescribe the Imiticides by mouth to stop young heartworms from growing. After the injections, it is crucial to keep your dog quiet and not engage in any exercise for at least six weeks. As the adult heartworms die, they can damage the heart muscle if your dog becomes too active.
There is currently no approved adult heartworm treatment therapy for cats, but various medications may treat underlying symptoms. A surgical procedure to extract the adult worms may be the best option if your pet’s heart is heavily infected. However, because heartworms in cats have a much shorter lifespan than the parasites that infect dogs, a spontaneous cure is more likely to occur through their body producing antibodies. After treatment, your veterinarian will schedule your cat for follow-up exams, as well as to attend to any side effects of treatment.
How to Prevent Heartworm Disease
It is important to know about mosquitoes and heartworms and why prevention is so important to our Texas pets. Prevention of canine heartworm disease revolves around daily or monthly doses of medication. This medication comes in chewable or treat forms to make administration easier.
All cats, regardless of their lifestyle, should be on year-round heartworm prevention. Available preventives for cats include oral ivermectin, topical moxidectin/imidacloprid, and topical selamectin. Please ask your veterinarian for the right prescription for your pet.
It is important to note that some dogs are more susceptible to the disease if they are outside more often. But keep in mind that mosquitoes can get into your house too. This makes housebound pets just as vulnerable to this disease as those animals that live outside. With mosquitoes and heartworms around, prevention is so important to our Texas pets.
Please Note: NEVER administer any heartworm preventive to your pet without prior consultation and heartworm testing by your veterinarian.
If you have a pet sitting service scheduled, please let us know about any heartworm prevention your pet may be on.