Zoonotic Potential of Guinea Pigs: Outbreak of Cryptosporidiosis Combined with Chlamydiosis in a Breeding Guinea Pig Herd.

In a guinea pig herd with 26 breeding animals, several in-dividuals of all age categories died (16/26) after three ani-mals had been newly introduced from another herd. Fur-thermore, the population suffered of apathy, anorexia, severe weight loss and conjunctivitis, as well as abortions and stillbirths. At the same time, the owner experienced a SARS-CoV-2 infection with pneumonia, which was con-firmed by taking a PCR test. Chlamydia caviae was detect-ed from the conjunctiva and vagina/uterus in one juvenile animal together with an intestinal Cryptosporidium wrairi infection. Oocysts were found histologically in the small intestine, which was confirmed by PCR. C. wairi is a par-asite adapted to guinea pigs with zoonotic potential, which causes diarrhoea with frequent deaths in larger guinea pig herds. C. caviae is also a zoonotic pathogen and often the cause of conjunctivitis, pneumonia and abortions in guinea pigs and can lead to upper respiratory tract disease, con-junctivitis but also severe pneumonia in humans. The in-creased death cases and the clinical signs could be traced back to an infection with Cryptosporidium wrairi, compli-cated by a co-infection of C. caviae. We suspect that the abortions were caused by C. caviae, but since the population was treated with various antibiotics effective against chla-mydial infections, it was no longer possible to verify this by PCR testing. Unfortunately, more animals succumbed and finally only two animals of the originally 26 were left. With this case report, we would like to point out to veterinarians that guinea pigs can be an important source of zoonotic infections for various pathogens, especially since they are popular pets and often come into close contact with children where hygiene might not always be strictly followed.