Heartworm is an insidious disease. Heartworms have spread to virtually all parts of the US and many parts of Canada since the early 1970s. Heartworms are spread only by mosquitoes; thus, areas heavily populated by these insects tend to have a greater incidence of heartworm disease. Mosquitoes are a nuisance to you, but to your pets they are a deadly enemy. The threat of mosquito bites can be present the whole year through.
Heartworm disease can strike both dogs and cats, although it is much more commonly seen in dogs. As their name implies, heartworms live in the blood of a dog's or cat's heart and adjacent blood vessels. The adult heartworms can grow to be up to 14 inches long. The adult heartworms living in the heart produce offspring, called microfilariae, which circulate in the infected animal's blood.
When a mosquito "bites" an infected pet, it sucks out blood containing the microfilariae. After about two weeks in the mosquito, the microfilariae become infective larvae. This step is necessary for the transmission of heartworm. When the mosquito bites another pet, the infective larvae are transmitted.
Once transmitted these heartworm larvae slowly migrate to the heart and large arteries of the lungs as they change and mature. It is at this stage that the heartworm preventive medications can stop the infection. Once the larvae change to stage 5 adults, the preventive medications are no longer effective. This is why the medication needs to be administered on a regular schedule as directed.
Heartworms can cause serious illness including heart failure, difficulty breathing and even death.
Canine heartworm disease symptoms include:
In many cases, there are advanced symptoms, but heartworms can cause permanent damage in your pets long before symptoms begin to show (which can be as long as 2 years after infection). Some dogs do not appear to have symptoms in the early stages others do. If not detected and controlled with proper treatment, heartworms can lead to congestive heart failure and death. Year-round preventive medication is your pet’s best defense.
Veterinary research has developed medications and procedures that have improved the treatment of canine heartworm disease. Prompt detection and early treatment are vital to a successful cure. Today, the majority of dogs with heartworm disease survive. Most are cured by medications. Some require surgery. Prompt detection prevents needless suffering. Treating a heartworm infection can still be risky and costly, and like any disease, taking preventive steps is a far better alternative.
Highly effective diagnostic testing and preventive medications have been developed in recent years. It is necessary to have a heartworm test prior to using a preventive. Severe or fatal reactions may occur if preventives are given to dogs with heartworm disease, or may create diagnostic confusion at a later date.
A small amount of blood is all that's necessary for a preliminary heartworm screening test that is very accurate in detecting the presence of heartworm. In many regions, this may be the only test needed before starting a preventive program. If the dog shows heartworm symptoms or has visited a known heartworm problem area, additional tests are recommended before a preventive or treatment program is started.
Common blood screening tests can verify the presence of heartworms. Radiographs or X-ray films and other sophisticated laboratory tests are used to detect heartworm disease. As a safeguard, annual screening tests are recommended even for dogs that are on heartworm preventives.
The currently available heartworm preventive medication is safe, effective and available in once-a-month doses. This medication prevents the larvae from developing into adult heartworms. Prescribed medications must be given as directed.
In addition, some heartworm prevention products also protect against other parasites such as roundworms, hookworm, whipworms, and even fleas. For this advantage and because heartworm prevention is so easy we recommend all pets (even indoor pets) be on heartworm prevention medication year-round.
Although heartworm is seen less frequently in cats, the disease poses a much greater danger. The outcome is often fatal.
There currently are no drugs approved for treating adult heartworm infestation in cats. Cats can be treated with canine medications, but this can lead to dangerous side effects, including lung failure and death. Another approach to battle the disease is by treating the symptoms, with hopes of the cat outliving the worms (heartworms live within a cat for about two years). However, this approach can result in sudden death as the worms exit through the pulmonary arteries to the lungs.
There are no consistent clinical signs of heartworm in cats. Common clues include coughing and rapid breathing. Other signs include weight loss and vomiting. However, all of these signs are also common in other diseases. Diagnosis is difficult for veterinarians and may include outside laboratory tests, radiographs, and ultrasound studies.
The good news is that there are heartworm prevention drugs available for cats. If you live in a heartworm infested area, or plan on visiting a heartworm area with your cat, your veterinarian can prescribe a preventive medication. These drugs are given once monthly and are very effective in cats and kittens.
Research continues into all phases of heartworm disease. For the latest advice drop us a line or give us a call @ 336-PETS.