Symptoms of heartworms in cats include coughing, breathing difficulties and loss of appetite, and a blood test at the vet’s office can confirm the infestation. Identify heartworm symptoms in a cat withadvice from a practicing veterinarian in this free video on pet care. Expert: James Talbott Bio: Dr. James R. Talbott is a staff veterinarian at Belle Forest Animal Hospital and Kennel in Nashville, Tenn. Filmmaker: Dimitri LaBarge