Studies on re-infestation of the cat with Aelurostrongylus abstrusus

Abstract

Seven kittens infected with 800 third stage larvae of Aelurostrongylus abstrusus displayed clinical signs of lungworm disease and excreted large numbers of first stage larvae. Attempts were made 388 days later to reinfect 5 cats with a similar dose of larvae. All 5 animals resisted the re-infecting dose and, on post-mortem and histopathological examination, it was impossible to differentiate between the lungs of the re-infected group and those of the 2 cats kept as controls. Two other cats given a primary infecting dose of 800 third stage larvae at the same time developed clinical signs and lesions characteristic of lungworm disease. It is concluded that infection can induce an immunity, the duration of which may be related to the presence of adult worms in the pulmonary tissues.