Detection, identification, and co-carriage patterns of different bacterial and yeast pathogens isolated from diarrheic and apparently healthy dogs and cats.

Infectious diarrhea in companion animals is one of the most common multi-factorial diseases in small animal medicine. This study aimed to investigate the prevalence and different carriage patterns of different enteropathogens, including E. coli, Salmonella spp., Campylobacter spp., and yeast, in diarrheic and apparently healthy dogs and cats. A total of 71 dogs (31 diarrheic and 40 healthy) and 70 cats (42 diarrheic and 28 healthy) were subjected to microbiological examination. Diarrheagenic E. coli (DEC) had a higher prevalence in diarrheic cats (64.3) compared to diarrheic dogs (48.4). Enterotoxigenic E. coli (ETEC), Shiga-toxin producing E. coli (STEC), Necrotoxigenic E. coli (NTEC), Enterohemorrhagic E. coli (EHEC), and Atypical Enteropathogenic E. coli (aEPEC) pathotypes were detected in both species, while Typical Enteropathogenic E. coli (tEPEC) pathotype was not detected in any canine or feline cases. EHEC was detected only in apparently healthy dogs and cats in percentages of 5% and 7.1%, respectively. A higher prevalence of Salmonella spp. was detected in 40% and 21% of apparently healthy dogs and cats, respectively, while Campylobacter spp. was mainly isolated from diarrheic dogs (71%) and diarrheic cats (66.7%), with no significant correlation (P = 0.3). Regarding the associated risk factors, there was no discernible association between the potential factors, including age, sex, breeds, and previous infection, and the shedding of DEC, Salmonella spp., and Campylobacter spp for feline cases. On the contrary, a higher prevalence of DEC was detected in the winter season at 75% with a significant correlation (P = 0.004). Furthermore, previous drug administration also found to affect Salmonella spp. fecal shedding significantly (P = 0.04). Diarrheic dogs revealed a higher non-significant prevalence of mixed pathogens' carriage (51.6%), whereas enteropathogens co-detection prevalence was higher in diarrheic cats (16.7%) than in apparently healthy cats (3.6%). The diagnosis of bacterial-associated diarrhea is challenging due to the detection of diarrheagenic pathogens in both diarrheic and apparently healthy animals. Moreover, the interactions between different diarrheagenic pathogens and commensals may either initiate or hinder the occurrence of diarrhea.