Pet Owners Sue Over Effectiveness Of Popular Heartworm Medication
BOSTON (CBS) - Most pet owners understand heartworm medication can save their dog or cat's life.
But some are now concerned that medicines used for years to prevent the disease may not work as well as they thought.
Heartworm is transferred to pets from mosquitoes. Ever year, it kills thousands of cats and dogs.
Veterinarian Ann Hohenhouse describes what takes place.
"The heartworms migrate first to the pulmonary blood vessels. The blood vessels in the lungs grow and as they multiply, they then back up into the heart," Hohenhouse explained.
Vets say heartworm can be prevented with a simple dose of medication each month.
But now the effectiveness of the most popular drug used to fight heartworm, Heartgard Plus, is being called into question.
WBZ-TV's Paula Ebben reports
In a lawsuit, a former Heartgard employee claims the company had evidence that the parasites developed resistance to the product's active ingredients and as a result, some pets got sick.
"I could speculate that it maybe could happen because we know that if you have a bacterial infection and you take an antibiotic for a long time, the bacteria can become resistant to that, said Hohenhouse.
Hohenhouse, says it's possible that a drug can lose potency over time, but she hasn't seen it with her patients.
In a separate class action suit, several pet owners say it did happen to them.
The company that owns Heartgard said they don't comment on the details of pending litigation.
In a statement, the company said it has acted appropriately and responsibly on all maters related to the allegations and they will vigorously defend the case.
The company went on to say it stands by the effectiveness of its products.
Dr. Jill Elliot specializes in holistic pet medicine. She tells owners to continue to give pets Heartgard and other pet medications.
But she says a healthy diet and heart and liver supplements may help pets fight heartworm if they are infected.
"The theory in the holistic side is if you build up the animal, it will have less susceptibility to these things even taking hold," said Elliot.
Whether it's lost some of its effectiveness or not, many vets believe Heartgard is still one of the best products on the market to protect your pet.
Heartworm can be detected by a simple blood test. Along with monthly doses of medication, regular visits to your vet will help detect the disease early.
Early on is when treatment is most effective.
