Model to Predict Septicemia in Diarrheic Calves

Abstract

The difficulty in distinguishing between septicemic and nonsepticemic diarrheic calves prompted a study of variables to predict septicemia in diarrheic calves <28 days old that were presented to a referral institution. The prevalence of septicemia in the study population was 31%. Variables whose values were significantly different (P < .10) between septicemic and nonsepticemic diarrheic calves were selected using stepwise, forward, and backward logistic regression. Variables identified as potentially useful predictors were used in the final model-building process. Two final models were selected: 1 based on all possible types of predictors (laboratory model) and 1 based only on demographic data and physical examination results (clinical model). In the laboratory model, 5 variables retained significance: serum creatinine > 5.66 mg/dL (>500 micromol/L) (odds ratio [OR] = 8.63, P = .021), toxic changes in neutrophils > or = 2+ (OR = 2.88, P = .026), failure of passive transfer (OR = 2.72, P = .023), presence of focal infection (OR = 2.68. P = .024), and poor suckle reflex (OR = 4.10, P = .019). Four variables retained significance in the clinical model: age < 5 days (OR = 2.58, P = .006), presence of focal infection (OR = 2.45, P = .006), recumbency (OR = 2.98, P = .011), and absence of a suckling reflex (OR = 3.03, P = .031). The Hosmer-Lemeshow goodness-of-fit chi-square statistics for the laboratory and clinical models had P-values of .72 and .37, respectively, indicating that the models fit the observed data reasonably well. The laboratory model outperformed the clinical model by a small margin at a predictabilty cutoff of 0.5, however, the predictive abilities of the 2 models were quite similar. The low sensitivities (39% and 40%) of both models at a predicted probability cutoff of 0.5 meant many septicemic calves were not being detected by the models. The specificity of both models at a predicted probability cutoff of 0.5 was >90%, indicating that >90% of nonsepticemic calves would be predicted to be nonsepticemic by the 2 models. The positive and negative predictive values of the models were 66-82%, which indicated the proportion of cases for which a predictive result would be correct in a population with a prevalence of septicemia of 31%.

Characterization of virulence factors in Escherichia coli isolated from diarrheic and healthy calves in Austria shedding various enteropathogenic agents

“…Diarrhoea due to the enterotoxigenic Escherichia coli (ETEC) is one of the most frequent bacterial diseases in neonatal calves and the predominant pathogen cultured from calves with septicaemia (Lofstedt et al, 1999). E coli was the bacterial agent cultured with the highest frequency from diarrhoeic and healthy calves in our study, a finding that agrees with results of Bendali et al (1999a) and Garcia et al (2000).…”

A review on major bacterial causes of calf diarrhea and its diagnostic method

“…Clinical disease due to E. coli in calves may be present as enteric or septicemic illness, being one of the most important causes of neonatal mortality in dairy calves. (Lofstedt et al, 1999). Some strains develop traits can be harmful to a host animal.…”

The Evaluation of Coagulation Profiles in Calves with Suspected Septic Shock

“…The mortality risk of live-born neonatal calves <1 month of age has been reported to range from 15% to 30% on farms with serious management problems (Martin et al, 1975;Lofstet et al, 1999). The majority of deaths are attributable to infectious disease: diarrhoea, pneumonia, and septicaemia are the most common disorders.…”