Bacteriological evaluation of dog and cat diets that claim to contain probiotics.

Nineteen commercial pet foods claiming to contain probiotics were evaluated. Selective bacterial culture was performed to identify organisms that were claimed to be present. Twelve diets claimed only to contain specific bacterial fermentation products, which does not necessarily indicate that live growth would be expected, but these products also included the term "probiotic" somewhere on the package, suggesting that live, beneficial organisms were present. No products contained all of the listed organisms, while 1 or more of the listed contents were isolated from 10 out of 19 products (53%). Eleven products contained additional, related organisms including Pediococcus spp, which was isolated from 4 products. No relevant growth was present in 5 (26%) products. Average bacterial growth ranged from 0 to 1.8 x 10(5) CFU/g. Overall, the actual contents of the diets were not accurately represented by the label descriptions.