Unusual cases of septicemic colibacillosis in neonatal beef calves

Abstract

Septicemic colibacillosis is a disease caused by Escherichia coli, and dairy calves are usually affected. The aim of this study was to describe cases of colibacillosis in beef calves. Two calves (cases A and B) aged 4 and 3 days, were born from heifers that suffered dystocia. The herd was grazing maize stubble and a polyphytic pasture with scarce vegetation covering the soil, because of intense rains flooded the field. The clinical signs and lesions were similar in both cases, and included depression, hypopyon, reluctance to move, dehydration, dyspnea, polyarthritis and hyperemia of scleral vessels. Both cases exhibited leukocytosis with neutrophilia, and immature forms (case A). E. coli was isolated from body fluids, liver, spleen and lung after necropsy. Moreover, the synovial fluid revealed an increased volume and fibrin clots (case A). E. coli was also recovered from the whole blood of the other calf (case B). The isolates obtained from different organs (case A) and blood (case B) were susceptible to gentamicin, ciprofloxacin and minocycline. The calf that remained alive (case B) responded favorably to a treatment for 3 days consisting of gentamicin, enrofloxacin, flunixin meglumine and oral rehydrating salts. No similar cases were observed during the calving season. The differential diagnosis of neonatal calf mortality in beef herds should include septicemic colibacillosis, mainly when risk factors mentioned above occur.