UF veterinary cardiologists perform rare procedure to remove heartworms from cat

University of Florida veterinary cardiologists manually removed three heartworms from an infected cat Dec. 17, dramatically improving his prognosis through a rare procedure performed at UF for the first time.

Darcy Adin, D.V.M., chief of the UF Veterinary Medical Teaching Hospital’s new cardiology service, removed the worms from the heart of the anesthetized cat, named Midnight, using forceps. Amara Estrada, D.V.M., located the heartworms using an echocardiogram.

“No additional worms were seen on two follow-up echocardiograms and antibody testing will be done in several months to confirm that the infection was cleared,” Adin said. “Midnight’s prognosis is very good.”

Heartworm disease is less common in cats than in dogs but can have more serious consequences.

“It is not uncommon for cats to experience respiratory distress or die suddenly from heartworm disease,” Adin said.

The disease is transmitted by mosquitoes that bite an infected animal and then pass the infection to other animals they bite. The incidence of heartworm disease is higher in states with warm climates, Adin added.

“Physically removing heartworms from cats is quite rare,” said Mark Kittleson, D.V.M., Ph.D., Adin’s former mentor and a professor in the department of medicine and epidemiology at the University of California, Davis’ veterinary college. “We have done it several times here, but probably only once every three or four years.”

He added that the incidence of heartworm in both dogs and cats varies because of the difference in mosquito populations from place to place.

“Most mosquitoes prefer dogs, although some like both,” Kittleson said. “There is only one species that I’m aware of that prefers cats.” There currently is no approved drug treatment for heartworm disease in cats, so they can only be treated for symptoms as they occur or by manually removing the worms.

Symptoms of heartworm disease can include coughing, vomiting, weight loss and difficulty breathing, according to the American Veterinary Medical Association.

“If worms are identified within the right atrium of the heart, they can be removed with forceps through the jugular vein,” Adin said.

“This can significantly reduce the worm burden — or cure the cat if we get all the worms.”

In recent years and at other institutions, Adin and Estrada, both board-certified veterinary cardiologists, collectively have extracted worms from three cats and eight dogs.

“We have actually performed four very successful procedures together since the cardiology service was formed at UF last month,” Estrada said. “Now we have pulled heartworms from a cat. Darcy and I share all of the procedures and perform every one of them together as a team.”