[Pets as permanent excretors of zoonoses pathogens]

When scrutinizing zoonoses with regard to risks for human beings, the spectrum of pathogens with dogs, cats and birds leading to persistent infections and consequently to the fact that the animals become carriers and permanent excretors is relatively small. Most of the zoonoses cause clinical symptoms and will be taken care of correspondingly. With regard to dogs there is a multitude of persistent infections that are transferred from the pet to the human being and vice versa. In reality, however, the importance of the dog as permanent excretor of zoonosis pathogens endangering human health is minimal, except for some parasitoses. As far as cats are concerned, the situation is totally different. Cats are carriers and permanent excretors of pasteurella, the pathogens of the so-called cat-scratch disease, trichophyton and microsporum species, toxoplasmosis and orthopox viruses. The new zoonosis feline pox serves as an example of the necessity of a permanent observation of persistently infected pets. Healthy, but persistently infected birds form a source of infection not to be underestimated. Through the beat of their wings they constantly stir up dried infectious excrements and dust and thus favour the airborn infection of human beings. Chlamydia psittaci, the Newcastle disease virus and Mycobacterium avium are of major importance in this context. The risk of transferring zoonosis pathogens from persistently infected pets to human beings can be minimized through prophylactic diagnosis, strict measures of hygiene, observation of the schedule of vaccinations for the respective species and regular use of anthelmintica.