Newly released revisions address the underdiagnosis and undermanagement of heartworm disease in cats.

The American Heartworm Society has updated its Feline Heartworm Guidelines regarding screening, mosquito control and treatment options.

“As an organisation dedicated to reducing the incidence of heartworm disease and its impact on pets, the AHS has long been concerned about the underdiagnosis and undermanagement of heartworm disease in cats,” said the organisation’s president, Dr. Jennifer Rizzo.

Significant revisions involve:

• Screening cats using both antigen and antibody tests.
• Conducting antigen testing with heat-treated serum.
• Conducting antibody testing with the Heska antibody test because of its greater sensitivity than other tests.

The guidelines note that heat-treated serum should be used when antigen testing to dissociate potential antigen-antibody immune complexes and obtain the most accurate results. A negative antigen test result in feline serum is up to 12 times more likely to be converted to a positive outcome with heat treatment compared with canine serum.

“There’s no question that testing limitations have been a significant factor in heartworm underdiagnosis in cats,” Dr. Rizzo said. “By using the most accurate screening procedures and screening cats on a more routine basis, we hope to greatly improve the veterinary profession’s understanding of the disease and initiate steps to best manage affected patients.”

The revised guidelines also highlight the importance of vector control, noting that it should focus on reducing mosquitoes in the cat’s environment rather than using mosquito repellents on the pet.

The American Heartworm Society continues to recommend that all cats receive year-round heartworm prevention. The revised guidelines include advice for treating heartworm-positive cats, including specific medication dosages and surgical removal techniques.

“We now have scientific information that supports a more proactive approach to heartworm diagnosis, as well as greater specificity in prevention and treatment approaches,” Dr. Rizzo said.

The guidelines and a summary may be downloaded at heartwormsociety.org/guidelines.