Dinner please!

Heartworm Disease – The Importance of Preventive Medicine

My Personal Story - Dreyfus

It was during my 4^th year of vet school between my necropsy and anesthesiology rotation that I got Dreyfus.  We met at a Petco in New Brighton, MN.  I was picking up cat litter and he was looking for a home.  He was in a wire cage that was stacked on top of another cage.  He was very thin, extremely filthy, had a tuft of hair sticking up on the top of his head and was shaking.  Around his neck he wore a camouflage collar that said “Will Bolt”.  The card attached to his cage said “Male Neutered Beagle. History unknown.  Found living with other strays on a dirt lot in Wisconsin.  Heartworm positive.”  It was love at first sight.  I adopted him not knowing how severe his heartworm disease was but, I figured if he didn’t make it at least his last few days would be in a warm and loving environment.  I paid his adoption few, picked him up and took him home.  The next day I took him in for a full work up and to see how severe his heartworm disease was.  We retested him for heartworm, which to no surprise he came up positive for.  He also tested positive for ehrlichia but thankfully wasn’t clinical for it.  His complete blood count and chemistry profile were perfect and his chest x-rays only had minor changes.  The radiologist wrote on his report “this is good news for the dog”.  We decided to treat his heartworm with the three dose protocol of Immiticide, meaning he’d get one dose now and then a month later get two doses 24 hours apart.  In theory it’s suppose to be the safest protocol because you’re killing the worms off slower.  In reality all dogs with heartworm disease are at extremely high risk for post-treatment pulmonary thromboembolism (obstruction of blood flow through the arteries of the lungs secondary to dead heartworms) and can die at anytime.  We began his treatment and I kept him quiet for 2 months and prayed.  Fortunately, Dreyfus was the perfect patient.  He kept himself extremely quiet, so thankfully I didn’t have to crate him.  I'd carry him outside (up and down three flights of stairs) four times a day to go to the bathroom. He wasn't allowed to walk and honestly he didn't want to walk he was too weak, so we'd sit in the grass and watch the world go by.  Fortunately, during his treatment he never had any adverse reactions.  I think he only coughed once.  Two months and again six months after his final treatment he was heartworm negative.  Slowly over time Dreyfus regained his strength and today his favorite thing to do is go on long walks.  Dreyfus is one of the lucky ones.  Most dogs with heartworm disease don't survive and the worst part is it's a completely preventable disease.   

Dreyfus right after being adopted.

Dreyfus 4 years later!

Please schedule an appointment with your veterinarian for a heartworm test and make sure your dog or cat is on heartworm preventative medication.  The are numerous medications on the market please talk with your veterinarian about which one is best for your pet. 

Brief Overview of Heartworm Disease

Heartworm disease is a very serious and potentially fatal disease that is caused by parasitic worms living in the right side of the heart and arteries of the lungs.  It can infect dogs, cats and other species of animals including in very rare instances humans.  Mosquitoes, infected with heartworm larvae, spread the disease.  Once an infected mosquito bites a dog, cat or other susceptible animal the heartworm larvae enter the blood stream and are transported into the arteries of the lung.  Over the next several months the larvae develop into mature adult worms where they continue their life cycle and cause serious injury to the lungs and heart. 

Cats are slightly different in that they typically have fewer worms than dogs.  Nevertheless these worms can still cause extensive damage to the arteries of the lungs.  Even one worm can kill a cat.  Outdoor cats are at greater risk of being infected, however an extremely high percentage of indoor only cats have been infected.   

It is important to remember that heartworm disease has been reported in all 50 states. 

Clinical signs

In dogs clinical signs may not be detectable in early stages because the number of worms in the animal accumulates over time.  Heavily infected dogs will show signs of mild to severe cough, reluctant to exercise, fatigue after a short amount of exercise, decreased appetite and weight loss.

Cats typically exhibit non-specific signs.  Clinical signs include vomiting, gagging, difficulty or rapid breathing, lethargy and weight loss.  Signs can be very similar to feline asthma. 

How to detect heartworm disease?

Heartworm disease can be detected with blood tests.  This is something that your veterinarian can and should do annually.      

Prevention

Heartworm disease is a preventable disease.  I repeat heartworm disease is a preventable disease.  There are numerous heartworm preventative medications currently on the market.  They are safe, easy to administer and inexpensive (especially compared to the treatment!).  Make sure you give them as directed by your veterinarian and do not miss a doses.  I recommend giving them year round so you don't get out of the habit of giving them.  Heartworm disease in dogs is potentially treatable but it is an extremely long, difficult and expensive process.  Keep in mind there is no effective treatment for heartworm disease in cats, so once again prevention is key.

Treatment

In dogs, adult heartworms are killed by a drug call Immiticide that is injected into the lumbar muscles through a series of treatments.  The dog then must remain extremely quiet for at least two months.  Post-Immiticide complication is development of severe life-threatening pulmonary thromboembolism (obstruction of blood flow through pulmonary arteries due to dead heartworms).   

Form more information on heartworm disease please visit http://www.heartwormsociety.org/