This study evaluated the fecal microbiota of 12 healthy pet dogs and 12 pet cats using bacterial and fungal tag-encoded FLX-Titanium amplicon pyrosequencing. A total of 120,406 pyrosequencing reads for bacteria (mean 5017) and 5359 sequences (one pool each for dogs and cats) for fungi were analyzed. Additionally, group-specific 16S rRNA gene clone libraries for Bifidobacterium spp. and lactic acid-producing bacteria (LAB) were constructed. The most abundant bacterial phylum was Firmicutes, followed by Bacteroidetes in dogs and Actinobacteria in cats. The most prevalent bacterial class in dogs and cats was Clostridia, dominated by the genera Clostridium (clusters XIVa and XI) and Ruminococcus. At the genus level, 85 operational taxonomic units (OTUs) were identified in dogs and 113 OTUs in cats. Seventeen LAB and eight Bifidobacterium spp. were detected in canine feces. Ascomycota was the only fungal phylum detected in cats, while Ascomycota, Basidiomycota, Glomeromycota, and Zygomycota were identified in dogs. Nacaseomyces was the most abundant fungal genus in dogs; Saccharomyces and Aspergillus were predominant in cats. At the genus level, 33 different fungal OTUs were observed in dogs and 17 OTUs in cats. In conclusion, this study revealed a highly diverse bacterial and fungal microbiota in canine and feline feces.

Previous work has shown obesity to be associated with changes in intestinal microbiota. While obesity is common in dogs, limited information is available about the role of the intestinal microbiota. The aim of this study was to investigate whether alterations in the intestinal microbiota may be associated with canine obesity. Using 16S rRNA gene pyrosequencing and quantitative real-time PCR, we evaluated the composition of the faecal microbiota in 22 lean and 21 obese pet dogs, as well as in five research dogs fed ad libitum and four research dogs serving as lean controls. Firmicutes, Fusobacteria and Actinobacteria were the predominant bacterial phyla. The phylum Actinobacteria and the genus Roseburia were significantly more abundant in the obese pet dogs. The order Clostridiales significantly increased under ad libitum feeding in the research dogs. Canine intestinal microbiota is highly diverse and shows considerable interindividual variation. In the pet dogs, influence on the intestinal microbiota besides body condition, like age, breed, diet or lifestyle, might have masked the effect of obesity. The study population of research dogs was small, and further work is required before the role of the intestinal microbiota in canine obesity is clarified.

Two female spayed dogs belonging to the same owner were admitted for further examinations because of clinical signs and laboratory values compatible with hyperthyroidism. Sonography of the ventral aspect of the neck revealed small thyroid glands in both dogs. The hypothesis that the dogs suffered from alimentary hyperthyroidism caused by feeding head meat containing thyroid gland tissue was confirmed by consultation of the slaughtering plant, determination of iodine concentrations in deep-frozen samples and hormone measurements in 5 other dogs receiving head meat from the same supplier. After changing the diet, thyroxine concentrations declined and clinical signs were no longer observed.