Heartworms. Not a topic most of us want to think about, let alone read about. And yet, we must. They are a reality, and they are killing dogs across the country.

 

It was once thought that Heartworms only occurred in the summer, and only in warm, moist climates. The truth is that heartworms have been reported in all 50 states. Reported cases are higher in the south: an average of 100 cases per clinic in parts of the Southeast and Gulf Coast areas versus 5 cases in Nebraska and Arizona; but at least one case per clinic was reported by every state, including Alaska and Hawaii (2007 figures).

 

So, how do dogs get heartworms? From an infected mosquito; there's no other way. Veterinarians disagree about many aspects of heartworm disease, including the treatment, but they all agree on this. Also, dogs cannot pass heartworms on to other dogs or cats or to humans. Heartworms are passed on by a mosquito. Period. And they are detected by a blood test.

 

Once a dog is bitten by an infected mosquito, it takes about seven months for the larvae to mature into adult heartworms. They lodge in the heart, lungs, and surrounding blood vessels of your dog and begin reproducing. Adult heartworms can grow up to 12 inches in length, and your dog can have as many as 250 worms in its system. Not good. These heartworms interfere with the normal flow of blood from the heart to the lungs, which eventually causes recognizable symptoms.

 

You can't rely on these symptoms to alert you that all is not well since they don't develop until the disease is very advanced in your dog. Then the symptoms mimic those of congestive heart failure: dull coat, lack of energy, coughing and difficulty breathing. Sometimes the dog experiences fainting spells and an enlarged abdomen.

 

The treatment for heartworms is almost as dangerous as the disease. The only medication currently designated to treat heartworms is Immiticide, an arsenic compound that must be injected into the lumbar muscle of the infected dog. Your vet may opt to give a series of three injections: the initial injection followed in 30 days with two injections 24 hours apart. This treatment is more expensive but carries less risk of damage to the lungs of the dog and less risk of other complications. Otherwise, two injections are administered 24 hours apart. Often other medications are given in conjunction with the Immiticide. The best thing for your dog once you bring it home is rest.

 

Just because your dog has been treated for Heartworm disease and survived does not mean he or she is immune from becoming re-infected. One bite from an infected mosquito, and you and your unprotected dog are back at square one.

 

We've already talked about the cure. Prevention usually involves one pill a month, pills that the dogs consider a treat. So the question remains: prevention or cure? The choice seems pretty simple.