Heartworm disease is transmitted from dog to dog by mosquitoes. Adult heartworms in dogs can be up to 30cm long and can cause serious disease. They live in the heart and blood vessels of the lungs, interfering with circulation and damaging tissues. This may eventually cause heart failure, and if left untreated, heartworm in dogs can be fatal.
Dogs rarely show immediate signs of heartworm infection as the adult worms take 6 to 7 months to develop from larvae transmitted by a mosquito bite. The signs of heartworm disease in dogs will depend on the severity of the infection, plus the health, activity level and size of your pet.
Common heartworm symptoms
Lack of energy
Reluctance to exercise
Start heartworm prevention for your dog from 6 weeks of age. It should stay on preventative treatment for life to avoid canine heartworm disease. Your vet can test for the presence of heartworm infection before starting heartworm prevention for the first time, or if heartworm prevention has been missed.
All untreated dogs are at risk of being infected by potentially deadly heartworm. That’s why it’s so important to protect your dog.