Heartworm Disease

Does your dog cough frequently? Has he lost some weight recently? Just doesn't want to go running after that tennis ball anymore? If so, he could have heartworm disease!

Dirofilariasis or heartworm is a serious and potentially fatal illness spread by mosquitoes and it is common especially in the eastern and southern parts of the USA.

When a mosquito bites a dog to take a blood meal, it may inject a number of tiny larvae into the animal's skin. Over a period of months, these larvae migrate into the blood stream and gradually make their way to the heart and the adjacent arteries. Here they begin to grow and can often reach lengths of twelve to eighteen inches! Sometimes dogs will have tens or even hundreds of worms, all more than a foot long, clogging up the chambers of the heart.

At this stage, the blood cannot flow properly through the heart and the dog starts to show the typical signs of congestive heart failure. To make things worse, the female worms produce thousands of offspring, which can be found swimming in almost every drop of blood in the dog's body. When the next mosquito bites the unfortunate animal, it will suck up some of these juveniles and then fly off to find it's next victim...

If you are suspicious of this disease in your pet, your veterinarian can do a specific blood test to detect the presence of the parasite. Other tests including a radiograph of the chest, an electrocardiograph and a full blood chemistry and blood count may be required for a definitive diagnosis.

Treating heartworm disease involves a series of injections that will kill the adult worms, as well as certain oral medications to eliminate the juvenile larvae. Although the newer drugs like melarsomine are safer than the arsenic type drugs used in the past, there is certainly no guarantee that your pet will survive the treatment. There are frequent complications and adverse reactions and very close monitoring is essential if your pet is to make a full recovery.

By far the safest way of dealing with heartworm disease is prevention. Newer medications available today are almost 100% effective in preventing the worms from ever reaching the heart. Depending on where you live, it is recommended that dogs be tested for the disease on a yearly basis. Even if you give your pet preventative medication, a yearly test is still important. Occasionally your dog may vomit the medicine or, just because we're human, we may forget to administer the tablet on time.

Recently,the once a month chewable heartworm preventatives have become the most commonly used among dog owners. In addition, these tablets are formulated to give protection against intestinal worms as well. Keeping your dog on the preventatives year round will ensure that he stays healthy and parasite free - even if it isn't mosquito season.