Background:Neonatal diarrhea affects nearly 25% of pre-weaned calves. Prevention through management practices is the preferable approach to control diarrhea. Once calves experience diarrhea, fluids, electrolytes and acid-base balance need to be restored. Severe cases of diarrhea should be treated with antimicrobials but the need of antimicrobials in mild and moderate clinical cases it is still under debate.

Objectives:The objective of this study is to evaluate the efficacy of antimicrobial treatments or the comparative efficacy of antimicrobials treatments in calves with mild, moderate and severe diarrhea.

Design: The search strategy will be based on population (calves with diarrhea), and intervention (antimicrobial therapy). The following data bases will be used: Medline, CAB abstracts, Scopus, and Biosis. The outcomes of interest will be the occurrence and persistence of clinical signs of diarrhea, rate of growth, weight gain, feed efficiency or mortality.

Background: The use of antimicrobials in the livestock industry has been a topic of increasing concern in the last  few years. Calf scours is one of the main causes of mortality among calves younger than 1 month and affects the development of the animal, representing severe economic losses to the producers. The causes of the disease include a variety of viral, bacterial and protozoal pathogens, and other non-infectious causes. The treatment efficacy, in particular of antimicrobial therapy, depends on the type of infection. Blanket antimicrobial treatment for calf scours without identification of the pathogen may contribute to antimicrobial resistance. In this review we explore the available literature for evidence of effective methods to prevent calf scours in cow-calf operations in California through the use of vaccination.

Objectives:  The objective of this scoping review is to examine and describe the existing literature on vaccination for the prevention of calf scours that might reduce the incidence of calf scours by different causes, and therefore reduce the use of antimicrobials due to calf scours.

Design: Primary research on vaccination for pathogens that cause calf scours will be considered for inclusion, such as studies conducted in pre-weaned calves that report the efficacy of vaccines for the prevention of calf scours. The process for selection and inclusion of the studies will be reported in a flow chart according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA). The results will be summarized in tables and charts describing study types, interventions and outcomes.