Archive for the ‘Heartworm’ Category

Are Heartworms Winning the War?

Thursday, April 21st, 2011

For many years we have been fighting a battle against heartworms. We have great products on our side to prevent this disease, but recent findings about heartworm resistance have many pet owners and veterinarians concerned.

Is it possible that heartworms are winning the war?

 Heartworm disease has been known to veterinarians for more than 120 years. The heartworms are transmitted from any of more than 70 known species of mosquito, and the disease attacks the pulmonary arteries and right side of the heart in dogs.  Heartworms are spread directly to the dog from the mosquito, with no dog-to-dog transmission. 

For more than 4 decades, heartworm disease has been effectively prevented in dogs by using available products.  But recent research indicates this might be changing. At a veterinary conference in 2010, information was released detailing a genetic mutation in heartworms that appears to confer slight resistance to current preventives.  Anecdotal reports in the last 4-5 years also point toward an increase in heartworm prevention product failures in the Mississippi delta region of the U.S.

While lack of efficacy (LOE) to heartworm preventives remains geographically limited, research is ongoing to determine the extent of this problem.  Historically, the LOE was attributed to poor owner compliance in the geographic area, the effects of Hurricane Katrina, increased heartworm numbers within the mosquito vector, and/or the increased sensitivity of heartworm testing.

Two prominent veterinary groups, the Companion Animal Parasite Council (CAPC) and American Heartworm Society (AHS) concluded at a recent council strategy session that most credible reports of LOE are geographically limited at this time.  In addition, the extent of this problem is not truly known.

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Heartworms Continue to Plaque Pets!!

Tuesday, May 11th, 2010

Each year, veterinarians do battle with an ancient enemy of our dogs and cats.  Heartworms are easily preventable with affordable and safe medications, but positive cases continue to rise.  Is there any hope that we could see an end to this parasite?

It’s been more than 150 years since a scientist discovered the heartworm parasite of dogs and more than 80 years since the parasite was found in cats.  Still, each year hundreds of thousands of dogs and cats are diagnosed with this dreaded worm and it is estimated that North American cases are actually in the millions.  In all this time, why have we not found a way to combat and stop this plague?

Heartworm disease is devastating to the pet’s health.  Spread by mosquitoes, this parasite can grow close to two feet long and takes up physical space in the heart’s chambers and pulmonary artery.  This means that the dog’s heart must work harder to push the same amount of blood out to the body.  Early signs of this disease included fatigue and exercise intolerance, but later signs can include coughing, fluid accumulation in the lungs or abdomen and death. 

For cats, the heartworm larvae prefer the lungs and can cause vomiting, asthma like symptoms and even sudden death in some cases.

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Heartworm Disease is Spreading

Thursday, May 6th, 2010

With over 250,000 known cases across the United States, canine heartworm disease continues to plague our pets, causing emotional distress to the owners and financial worries to their pocketbooks.  The saddest part of all:   this disease is completely preventable.

We know what causes heartworm disease, we know how to treat it in dogs, and we even have safe, effective medications to prevent the disease.  So, why are more than a quarter of a million dogs and cats still getting this terrible disease?

According to a survey recently released by the American Heartworm Society over 250,000 dogs and cats tested positive for heartworm infection nationwide in 2004.  Since these cases only included dogs that routinely see the veterinarian, some estimates of the true incidence of heartworms in dogs range as high as 11 million canines infected with the parasite.  Throw in coyotes and foxes and one can easily see the huge reservoir of potential cases.

Heartworms are a parasite that reside in the vessels leading from the heart to the lungs of many different mammals, but are primarily suited for life in a canine.   The immature larva of the adult heartworms are taken in during feeding by mosquitoes and then spread from mosquito back to dogs after a short, 2 week maturation period in the mosquito’s stomach and salivary glands.  After returning to their natural host, the heartworm larva migrate through the dog’s body over the next four to six months, growing in length until they reach the heart.  Upon reaching the heart, the foot long parasite becomes sexually active, producing large numbers of larva, which, in turn, wait to be picked up by a feeding mosquito, continuing the disease cycle.  Infected dogs might have as few as 5 or 6 adult worms or as many as 250!

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Battle Against Heartworms Getting Tougher!?!

Tuesday, March 24th, 2009

Every Month, lots of dog owners and a few cat owners, give their pets some form of heartworm prevention. It is now time to start worrying about the spread of heartworm with the start of spring and mosquitoes here in the Northeast. But recent studies are showing increasing numbers of heartworm positive pets across the country. Some people believe the worms now have the upper hand. Has our trusted protection failed us?

Dog owners, and a growing number of cat owners understand that once-a-month heartworm preventatives keep their pets safe from a very serious cardiovascular parasitic disease. Despite consistent use of preventive medications, a significant number of dogs are testing positive for heartworms, especially in the mosquito heavy Southeastern US. Are we seeing the beginnings of a resistance movement?

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