Table 1.
Assigned reasons for euthanasia of 252 critically ill neonatal calves with diarrhea based on a review of 1,400 medical records.
Table 2.
Relative frequencies of documented post-mortem findings in a total of 302 calves with neonatal diarrhea.
Table 3.
Results of univariate logistic regression analysis of the association of clinical signs within 48 hours of admission with mortality during hospitalization of 1,400 critically ill neonatal calves with diarrhea.
Table 4.
Laboratory findings on admission of 1,400 critically ill neonatal calves with diarrhea categorized on survival to discharge from the hospital.
Fig 1.
Observed survival rates of 1,400 critically ill neonatal calves with diarrhea in deciles of selected blood gas and acid-base variables.
Dashed vertical lines indicate the reference range of respective variables [7, 46, 51] and the dashed horizontal line indicates the overall survival rate of calves of this study population. Survival rates of decile groups that were significantly different (P ≤ 0.006) from the survival rate of the reference group (arrow) are indicated by asterisks.
Fig 2.
Observed survival rates of 1,400 critically ill neonatal calves with diarrhea in deciles of electrolyte, phosphorus, and L-lactate and D-lactate concentrations.
Dashed vertical lines indicate the reference range [40, 46, 51, 52] of respective variables and the dashed horizontal line indicates the overall survival rate of calves of this study population. Survival rates of decile groups that were significantly different (P ≤ 0.006) from the survival rate of the reference group (arrow) are indicated by asterisks.
Fig 3.
Observed survival rates of 1,400 critically ill neonatal calves with diarrhea in deciles of selected serum/plasma concentrations or activities.
Dashed vertical lines indicate the reference range [46, 52] of respective variables and the dashed horizontal line indicates the overall survival rate of calves of this study population. Given that calves in the first two weeks of life with serum gamma glutamyltransferase activity < 50 U/L should be classified as having failure of passive transfer of immunoglobulins [53], this cut-point value was chosen as reference range for this parameter. Survival rates of decile groups that were significantly different (P ≤ 0.006) from the survival rate of the reference group (arrow) are indicated by asterisks.
Table 5.
Multivariate logistic regression models for identifying associations of clinical and laboratory variables with actual mortality in 1,400 critically ill calves with diarrhea.
Fig 4.
Estimated classification tree identifying significant associations between clinical and laboratory variables and observed mortality.
Each oval identifies a subset of the population, the probability of mortality for the subset, and the number of calves in the subset. Lines leaving the oval identify a study variable and its cutpoint value that is a significant predictor of mortality. Branches to the left indicate subgroups with lower mortality (better outcome), whereas branches to the right indicate subgroups with higher mortality (poorer outcome). Classification tree analysis indicated that observed mortality was associated with the presence of central nervous system disease, ileus or abdominal emergency, a cachectic body condition, presence of orthopedic problems, and a jugular venous blood pH < 6.85.
Fig 5.
Estimated classification tree identifying significant associations between laboratory variables and observed mortality.
Each oval identifies a subset of the population, the probability of mortality for the subset, and the number of calves in the subset. Lines leaving the oval identify a study variable and its cutpoint value that is a significant predictor of mortality. Branches to the left indicate subgroups with lower mortality (better outcome), whereas branches to the right indicate subgroups with higher mortality (poorer outcome). Classification tree analysis indicated that observed mortality was associated with plasma glucose concentrations < 3.2 mmol/L, plasma sodium concentrations ≥ 151 mmol/L, GGT activity < 31 U/L and a thrombocyte count < 535 G/L in hypoglycemic calves.
Table 6.
Multivariate logistic regression models for identifying significant associations between study variables and predicted mortality in calves of the present study population.
For this analysis euthanized calves were allocated to the survival group if the calf would likely have lived if unlimited financial resources were available. For this purpose medical records were independently reviewed by three experienced clinicians.