Selective use of antibiotics in calves with neonatal diarrhea : preliminary data

This study investigates the role of antibiotics in the treatment of calves with Neonatal Calf Diarrhea (NCD), widely employed in the field although their controversial efficacy [1]. The Ministry of Health approved this study (approval number 14/2018). Twenty four Friesian calves with NCD, aged from 1 to 28 days were enrolled, excluding those with other concurrent neonatal diseases. Upon admission, dehydration was estimated as body weight percentage (b. w.) and the acid-base imbalance was assessed by venous blood-gas analysis. Fecal antibiotic susceptibility tests were also done. Treatment consisted of natrium bicarbonate, 0.9% natrium chloride saline solution and glucose infusion, NSAID (flunixin meglumine, 2.2 mg/kg b.w. IV) and vitamin E-selenium, as previously reported [2]. After emergency therapy, calves were randomly assigned to Group A (antibiotic-treatment group) or Group B (antibiotic-free group). Group A received ampicillin (10 mg/kg IV q12h for 5 days), a wide spectrum antibiotic, as described by Constable [1], as the antibiogram results were delayed. Each calf was monitored for 28 days. Calf Health Scoring Chart (CHSC), average daily gain (ADG) and sepsis score [3] were recorded daily. Calves of both groups whose general conditions deteriorated (sepsis score > 60%) were given an antibiotic based on antibiotic susceptibility tests. Descriptive statistics, chi-square test for categorical variables, T-test and general linear model for repeated measures for continuous variables were performed using SPSS. In the general linear model, treatment with antibiotics in group B and changes in active substances in group A were considered for statistical analysis. The ADG in calves A and B was 11 ± 0.4 kg and 13 ± 5 kg, respectively (p= 0.146). The average sepsis score in group A was 29%; 4 of 12 calves developed a sepsis score >60% so their antibiotic was changed. The average sepsis score in group B was 24%; 4 of 12 calves developed a high risk of sepsis (>60%) and so received antibiotics. Mortality rate in group A and B was 33.3% and 25%, respectively (p= 0.202). The CHSC revealed no statistical differences between groups. Our data suggests antibiotic treatment should be given to calves based on the high probability of developing sepsis and avoided in cases of uncomplicated NCD.