Critical review on the usage of antimicrobials and on the restoration of the intestinal environment in canine acute and chronic diarrhea

Antimicrobials (AMs) are used in many cases of acute and chronic diarrhea in the dog. The aim of the present manuscript is to critically review the current literature trying to define how frequently bacteria effectively cause acute and chronic diarrhea and which are the most frequent clinical effects of antimicrobials' use. In addition, a brief overview of the main approaches to restore the intestinal environment is given. It resulted that antimicrobials do not always improve the clinical condition, unless bacteria are an established cause of the observed clinical signs (e.g. diarrhea), as rarely happens, or the related complications (e.g. sepsis). AMs should not be used empirically as a tool in the diagnostic work-up, neither in acute nor in chronic diarrhea and the presence of fresh blood in stools should not necessarily imply the obligation to resort to antimicrobials use.