Diarrhoeal diseases of the calf: Observations on treatment and prevention

Abstract

Extract

During the past two decades intestinal absorptive and secretory functions and the intestinal flora have been significantly clarified. Important concepts of intestinal dysfunction have emerged which have proved of immense clinical value(32) (39) (46) (47) (51). Despite this, the medical and economic consequences of diarrhoea continue to beset the cattle industry(1) (18) (30) (56) (57). Diarrhoeal disease of the calf occurs at a time of complex developmental, environmental and functional change. The surface defences and enzyme systems of the neonatal gut are maturing in a protective film of maternal antibody, while undergoing increasing stimulation from environmental microbial challenge. The precarious nature of this defence system is not surprising. It is contingent upon a balance of such changing conditions as maternal antibody quantity, quality and delivery(5), environmental microbial challenge(46) (47) and neonatal immunological and intestinal epithelial maturation(7) (52). While both infectious and non-infectious etiologic factors are involved(1) the former (Escherichia coli, Saltiionsllci and Shigella spp., and reo and corona viruses) is the more significant. Enteropathogenic E. coli (EPEC), a major contributor to neonatal diarrhoeal disease, will be discussed primarily. Four syndromes, septicaemia, enteric-toxaemia, local invasive and enterotoxic have been described(32) and ad verseoutcomes may result from endotoxic shock and/or hypovolemic shock, from systemic infection and from malnutrition. The clinician is thus faced with the selection of a multi-faceted approach to the problem. Avenues of attack, in addition to prophylactic husbandry, include: passive and active immunization, reduction of challenge, specific antimicrobial therapy, and resolution of fluid and electrolyte loss and shock. This presentation includes a resumé of the calf scour syndrome, together with observations concerning treatment and control. These observations include active and passive immunization, antimicrobial therapy, and modification of intestinal fluid loss.