About 50 % of cats with heartworm disease will have evidence of enlarged pulmonary arteries
on x-rays of their lungs.14 However, these findings can be found with other parasitic
infections such as roundworms (Toxocara) and
lungworms (Aelurostrongylus).
Also common are lung diseases associated with
infection by feline immunodeficiency virus (FIV) and those caused by such parasites as heartworms and
lungworms, although the prevalence of those parasitic
infections depends to a great extent
on geographical, climatic and seasonal factors.