Because of this life cycle, it is necessary for a cat to be bitten by an infected mosquito in order to become infected with heartworms. (michigananimalhospital.com)
Spread by infected mosquitoes, heartworm is increasingly being recognized as an underlying cause of health problems in domestic cats. (aspca.org)
It takes about 6 months after being bitten by an infected mosquito for a dog to test positive for heartworms. (salmonbrookvets.com)