A large number of worms dying at once can cause the death of the patient. (scenichillsvet.com)
In both kittens and adult cats with small numbers of worms, there may be no clinical signs of infection. (brittonroadveterinaryclinic.com)
Since the heartworm can live so long, this can lead to an increasing number of worms in an animal as a pet becomes infected over and over each mosquito season. (blog.nhvnaturalpetproducts.com)