Only Drug That Treats Heartworm No Longer Available
by Rikki Schmidt

If ever there was a reason to get your dog on heartworm preventative, this is it. The only heartworm treatment approved by the U.S. Food and Drug Administration for use in dogs that have contracted the deadly disease is temporarily unobtainable and it is not known when the drug will again become available.

The drug, Immiticide, used to treat dogs who have contracted heartworm, is an arsenic compound that kills adult worms. It should not be confused with the once a month heartworm preventative which goes by many brand names and remains readily available.

News of the situation came to light in early August when veterinarians received a letter from the drug maker, Merial, warning of a shortage that could last for several weeks or months. That notice caused a run on the remaining inventory. Recently, a spokesperson for Merial has now confirmed that they are “officially out” of Immiticide.

The trouble started in 2010 when Merial reported that its U.S. supplier was having difficulty obtaining the product’s active ingredient and the FDA was reluctant to let Merial’s overseas supplier fill American orders. However it has been stated that this recent situation is not related to last year’s problems, rather it concerns technical issues in manufacturing the finished product.

Meanwhile veterinarians treating sick dogs are turning to a heartworm preventative and doxycycline to manage the disease. This alternative is less than ideal since the preventative can cause reactions in dogs already infected and the drugs do not treat the main problem which are the adult worms. Treating an infected dog is not easy. Activity must be severely restricted to reduce the chances of a blood clot. Exercise increases the heart rate which raises the risk that fragments of dead worms in blood vessels could cause a thromboembolism.

Most heartworm cases are diagnosed before dogs show any symptoms, usually during a routine exam. The once a month preventative was considered an optional choice for dog owners in the greater Phoenix area since heartworm is not as prevalent here as in other cities. However the number of cases are increasing and now with no medication on hand, more sick dogs will go untreated and more mosquitoes will get infected and pass the disease on.

Even when the drugs were available, the arsenic-based treatment for heartworm was difficult, dangerous, lengthy and expensive. Now, even that is not an option to combat this deadly disease. It is recommended that dog owners get their dogs tested and get them on preventative as soon as possible.

AS THE (HEART) WORM TURNS
by Rikki Schmidt

There's a lot about Arizona we can brag about to friends who live elsewhere; lots of sunshine, low humidity, no pesky daylight savings time. But one of the greatest benefits was what we didn't have ... mosquitoes! Last winter's rains however; along with an increasing number of man-made water features and stagnant swimming pools in foreclosed homes, have resulted in a glut of mosquitoes. This means more than just running out and buying a big flyswatter.

Mosquitoes mean heartworm, and heartworm means big trouble for dogs. An increasing number of heartworm cases are now being diagnosed in dogs throughout Arizona including Queen Creek and San Tan Valley.

Heartworm is a very serious and often fatal disease that is transmitted between dogs via mosquitoes. It only takes one infected dog and a cooperating mosquito to put other dogs at risk. The disease is caused by a parasitic worm that, in its adult stage, lives in the heart and the major artery to the lungs. Heartworm is not transmitted by blood transfusions and is seldom found in people but there have been occasional cases where cats have contracted it.

Unfortunately, heartworm can be present for a number of years before any symptoms are noticed, and by that time the disease is well advanced. Signs of heartworm in a dog may include coughing, difficulty breathing, fatigue, and weight loss. The only way to know if your pet is infected is to have a blood test done. If the test is negative then your dog can be placed on preventative treatment that consists of an easy to administer once-a-month chewable tablet.

If, unfortunately, a dog tests positive for heartworm, the treatment is very expensive, lengthy, unpleasant, and may come too late to save your pet. And no dog is really safe. Even if your area is considered relatively mosquito-free, you can put your pet at risk if you take your dog with you when you go hiking, camping or fishing.

So, get your dog tested for heartworm and begin the year round preventative regimen. Then all you'll have to worry about from mosquitoes is that annoying, buzzing sound that keeps you up all night... oh yes, and West Nile Virus..( to be continued)