Salmonellosis impacts the proportions of faecal microbial populations in domestic cats fed 1–3-d-old chicks

There has been a recent increase in the feeding of unconventional diets, including whole-prey diets, to domestic pet cats. Our objective was to characterise faecal microbial populations of domestic cats fed whole and ground (6·35 mm grind) raw 1–3-d-old chicks (Rodent Pro). Faecal samples were collected from neutered male domestic cats (mean age = 5·7 years) fed these diet items in a crossover design. Bacterial DNA was isolated from faecal samples and amplicons of the 16S rRNA V4–V6 region were generated and analysed by 454 pyrosequencing. Faecal microbial populations of cats fed whole v. ground chicks did not differ. During the study, three cats presented with symptoms of infection (anorexia or diarrhoea) and tested clinically positive for Salmonella using a standard PCR method. The remaining cats tested negative. Data were analysed post hoc to test for differences in microbial populations due to clinical status. The predominant genera were Clostridium (9–30 %), unidentified Lachnospiraceae (10–28 %), Blautia (4–19 %), Peptococcus (2–19 %) and Fusobacterium (2–14 %). Faeces of cats testing clinically positive for Salmonella had higher (P ≤ 0·05) proportions of the genera Coprococcus (5·6 v. 0·4 %) and Escherichia (subgenera Shigella; 1·1 v. 0·3 %). Salmonella was not detected in faecal samples utilising the pyrosequencing method; however, there was a shift in microbial populations due to clinical status. The clinical symptoms reported herein may be not only due to the Salmonella itself, but also shifts in other gut microbial populations.