[A herpesvirus-caused enzootic--Pacheco's parrot disease--in a psittacine collection]

After the official confirmation of psittacosis in a collection of psittacine birds a total of 40 of them died during treatment with tetracycline. 36 of them underwent post mortem examination. From 33 birds the causative herpesvirus of Pacheco's parrot disease (PPD) was isolated and/or a non-purulent hepatitis diagnosed, the latter a characteristic for PPD. The cause of the outbreak was assumed to be a latent herpesvirus infection of individual birds which was activated by various stress factors during the psittacosis treatment. The macroscopic and histologic lesions, the results of virological investigations and the in vitro effect of acyclovir on the multiplication of the isolated herpes virus are described.