Dog owners are well aware of the threat of heartworm disease, but many pet owners would be shocked to know that their cats are in danger as well.   Heartworms are spread by mosquitoes and are capable of infecting cats in addition to dogs. Unfortunately, our cats rarely show physical signs of this infection and are more likely to die due to their body’s reaction to the parasite. The good news is that your veterinarian can help you prevent this deadly feline disease.