Cats and dogs are frequently kept in close contact offering the possibility of interspezies transmissions of coronaviruses.In order to get more insights about the occurrence of such recombination events under field conditions, faecal samples of 87 cats and 22 dogs, originating from an animal shelter, were examinated for coronaviruses, focussing on the genetic make up of their S and M protein genes. The samples were investigated for coronavirus specific nucleic acids by PCR, 52,9% of the cats and 77,3% of the dogs were positiv in their faeces.
PCRs differentiating in the S gene revealed a clear predominance of FCoV type I in cat samples, while no type I could be detected in dog samples. Remarkably, in contrast to earlier studies, typing in this genomic region was not successful in 50 % of the cat samples and in 41 % of the dog samples. Concerning the typing in the M gene region 64.7 % of the positive dog samples could be assigned to the FCoV-like CCoV.
Surprisingly the same M gene region could also be amplified from 56.5 % of the coronavirus positive feline faecal samples, but not from various feline reference strains. To our knowledge, these results in feline field samples have not been published yet. A significant correlation was found between the duration of stay in the shelter and the prevalence of these M gene PCR positive feline field samples, as this type could only be detected in cats which had been in the shelter for at least 7 days.
The results may indicate that coronaviruses of carnivores are frequently transmitted between dogs and cats which are living in close contact eventually leading to recombinant variants.