The Vet files #1 Heartworm

Myths and facts about heartworm from the front lines:

Myth: Heartworm isn’t a problem where I am

Fact: Since Hurricane Katrina in 2005, when thousands of HW+ dogs were spread across the country, heartworm is considered endemic in the entire United states. Some areas have more incidences and some have less, but "less" is not "none". If you are one of the unlucky ones, less doesn't mean anything at all.

Myth: Giving a monthly preventative is more expensive than just treating the disease.

Fact: A 12 month supply of Ivermax Heart (generic Heartgard) costs 110 dollars for a 100 pound dog. A 100 pound dog being treated for heartworm costs, on average, $1000 - enough for almost 9 years of preventative!

Myth: My dog breed can’t have heartworm medication due to risk of adverse outcomes.

Fact: With the exception of dogs which have an Mdr1 defect or dogs with epilepsy (note, this does not include “epilepsy-prone” breeds, only dogs WITH epilepsy), heartworm preventative causes few problems. A few dogs get diarrhea, vomiting or little loss of coordination in rare cases. These have been the reported common side effects.

Myth: The prevention is more damaging than the cure.

Fact: The cure for heartworms is Melarsomine. Dogs treated with Melarsomine must be under medically monitored total rest for 30 days. Melarsomine kills adult worms and fragments of those dead worms can break off in the heart or lungs and cause pulmonary embolism, pulmonary edema (fluid in the lungs), coma and even death 14% of the time. Not to mention the permanent and irrevocable enlargement of a dogs heart and arteries if the heartworm disease is advanced enough.

Myth: If my dog gets heartworms, I will just start him on Heartgard.

Fact: In the 2001 study on which this “slow kill” protocol is based, the study’s authors observed that after 30 months of treatment with ivermectin at preventative doses, 7 month old worms were reduced by 94% and 8 month old worms by 56%. Heartworms can reproduce at approximately 6 months of age. The common ELISA snap test detects infection well and reliably 6 to 7 months after infection. During those 30 months of treatment, adult heartworms continue to breed, grow and damage the heart and lungs because they are not killed by ivermectin at preventative dosing. That’s a long time to have a 2 foot worm clogging your pulmonary artery.

Give a hoot - give heartworm prevention!