Clinical signs, profound acidemia, hypoglycemia, and hypernatremia are predictive of mortality in 1,400 critically ill neonatal calves with diarrhea

Clinical and laboratory predictors for bacteremia in critically ill calves

BACKGROUND

Sepsis is a main contributor to calf mortality, but diagnosis is difficult.

OBJECTIVES

Develop and validate a predictive model for bacteremia in critically ill calves (CIC).

ANIMALS

A total of 334 CIC, sampled for blood culture.

METHODS

Cross-sectional study. Multivariable logistic regression and classification tree analysis on clinical, ultrasonographic, and laboratory variables were performed on a dataset including all animals. Model validation was done on 30% of the dataset. Similar statistics (except validation) were performed on a subset of the database (n = 143), in which presumed contaminants were excluded.

RESULTS

The best performing model to predict bacteremia, taking all detected bacteria into account, included tachypnea, tachycardia, acidemia, hypoglycemia, venous hypoxemia, and hypoproteinemia. Sensitivity and specificity of this model were 70.6% and 98.0%, respectively, but decreased to 61.5% and 91.7% during model validation. The best-performing model, excluding presumed contaminants, included abnormal temperature, heart rate, absence of enteritis, hypocalcemia, and hyperlactatemia as risk factors for bacteremia. Sensitivity and specificity of this model were 71.4% and 93.9%, respectively. Both classification trees performed less well in comparison to logistic regression. The classification tree excluding presumed contaminants, featured hypoglycemia, absence of diarrhea, and hyperlactatemia as risk factors for bacteremia. Sensitivity and specificity were 39.4% and 92.7%, respectively.

CONCLUSIONS AND CLINICAL IMPORTANCE

Hypoglycemia, hyperlactatemia, and hypoproteinemia seem relevant in assessing bacteremia in CIC. The performance of these models based on basic clinical and blood variables remains insufficient to predict bacteremia.

HEMATOLOGY AND BIOCHEMICAL REFERENCE INTERVALS FOR FREE-RANGING PRONGHORN (ANTILOCAPRA AMERICANA) IN WEST TEXAS

Pronghorn (Antilocapra americana) are considered a keystone species of North American grasslands and an important economic source for many landowners in Texas. Pronghorn restoration projects routinely capture and translocate individuals from surplus populations to restoration areas. The objective of this study was to generate normal hematological and biochemical reference intervals (RI) for free-ranging pronghorn populations in Texas as a health monitoring tool for pronghorn restoration efforts. Blood samples were collected by jugular venipuncture and divided among an EDTA tube, serum separator tube, and a single blood smear on site. Complete blood counts and biochemical profiles were completed at the Texas Veterinary Medical Diagnostic Laboratory. In total, 417 individuals (41 males, 376 females) were included in the analysis. RI were determined by robust methods (R Studio) and mixed models' analysis of variance (SPSS 28) to examine differences in blood parameters due to fever, sex, age (adult versus yearling [<1 yr of age]), cell abnormalities, and pathogen exposure reported by the testing laboratory. Sex, age, and pathogen exposure affected mean blood values, but did not warrant development of separate RI by class. Bluetongue virus was identified in 46.8% (195/417) of pronghorns and epizootic hemorrhagic disease in 89.4% (194/217) of pronghorns; 84.8% (184/217) of the pronghorns tested positive for both diseases. This information provides baseline hematology and biochemical parameters to assess the health of free-ranging pronghorn and guide wildlife managers in decision-making for future translocations and restoration objectives.

Determining lactate concentrations in Korean indigenous calves and evaluating its role as a predictor for acidemia in calf diarrhea

BACKGROUND

Calf diarrhea leads to high mortality rates and decreases in growth and productivity, causing negative effects on the livestock industry. Lactate is closely associated with metabolic acidosis in diarrheic calves. However, there have been no reports on lactate concentrations in Korean indigenous (Hanwoo) calves, especially those with diarrhea. This study aimed to determine the reference range of L-lactate and D-lactate concentrations in Hanwoo calves and to better understand the utility of lactate as predictive factors for acidemia in diarrheic calves.

RESULTS

L-lactate and D-lactate concentrations were measured in healthy (n = 44) and diarrheic (n = 93) calves, and blood gas analysis was performed on diarrheic calves. The reference range in healthy calves was 0.2-2.25 mmol/L for L-lactate and 0.42-1.38 mmol/L for D-lactate. Diarrheic calves had higher concentrations of L-lactate and D-lactate than healthy calves. In diarrheic calves, L-lactate and D-lactate each had weak negative correlation with pH (r = - 0.31 and r = - 0.35). In diarrheic calves with hyper-L-lactatemia, the combined concentrations of L-lactate and D-lactate had moderate correlation with pH (r = - 0.51) and anion gap (r = 0.55). Receiver operating characteristic analysis showed D-lactate had fair predictive performance (AUC = 0.74) for severe acidemia, with an optimal cut-off value of > 1.43 mmol/L. The combined concentrations of L-lactate and D-lactate showed fair predictive performance for predicting acidemia (AUC = 0.74) and severe acidemia (AUC = 0.72), with cut-off values of > 6.05 mmol/L and > 5.95 mmol/L.

CONCLUSIONS

The determined reference ranges for L-lactate and D-lactate in Hanwoo calves enable the identification of hyper-L-lactatemia and hyper-D-lactatemia. Diarrheic calves exhibited increased lactate concentrations correlated with acid-base parameters. While the concentrations of L-lactate and D-lactate have limitations as single diagnostic biomarkers for predicting acidemia or severe acidemia, their measurement remains important, and L-lactate has the advantage of being measurable at the point-of-care. Assessing lactate concentrations should be considered by clinicians, especially when used alongside other clinical indicators and diagnostic tests. This approach can improve calf diarrhea management, contributing positively to animal welfare and providing economic benefits to farms.

The development and validation of a milk feeding behavior alert from automated feeder data to classify calves at risk for a diarrhea bout: A diagnostic accuracy study

The objective of this diagnostic accuracy study was to develop and validate an alert to identify calves at risk for a diarrhea bout using milk feeding behavior data (behavior) from automated milk feeders (AMF). We enrolled Holstein calves (n = 259) as a convenience sample size from 2 facilities that were health scored daily preweaning and offered either 10 or 15 L/d of milk replacer. For alert development, 132 calves were enrolled and the ability of milk intake, drinking speed, and rewarded visits collected from AMF to identify calves at risk for diarrhea was tested. Alerts that had high diagnostic accuracy in the alert development phase were validated using a holdout validation strategy of 127 different calves from the same facilities (all offered 15 L/d) for -3 to 1 d relative to diarrhea diagnosis. We enrolled calves that were either healthy or had a first diarrheal bout (loose feces ≥2 d or watery feces ≥1 d). Relative change and rolling dividends for each milk feeding behavior were calculated for each calf from the previous 2 d. Logistic regression models and receiver operator curves (ROC) were used to assess the diagnostic ability for relative change and rolling dividends behavior relative to alert d) to classify calves at risk for a diarrhea bout from -2 to 0 d relative to diagnosis. To maximize sensitivity (Se), alert thresholds were based on ROC optimal classification cutoff. Diagnostic accuracy was met when the alert had a moderate area under the ROC curve (≥0.70), high accuracy (Acc; ≥0.80), high Se (≥0.80), and very high precision (Pre; ≥0.85). For alert development, deviations in rolling dividend milk intake with drinking speed had the best performance (10 L/d: ROC area under the curve [AUC] = 0.79, threshold ≤0.70; 15 L/d: ROC AUC = 0.82, threshold ≤0.60). Our diagnostic criteria were only met in calves offered 15 L/d (10 L/d: Se 75%, Acc 72%, Pre 92%, specificity [Sp] 55% vs. 15 L/d: Se 91%, Acc 91%, Pre 89%, Sp 73%). For holdout validation, rolling dividend milk intake with drinking speed met diagnostic criteria for one facility (threshold ≤0.60, Se 86%, Acc 82%, Pre 94%, Sp 50%). However, no milk feeding behavior alerts met diagnostic criteria for the second facility due to poor Se (relative change milk intake -0.36 threshold, Se 71%, Acc 70%, and Pre 97%). We suggest that changes in milk feeding behavior may indicate diarrhea bouts in dairy calves. Future research should validate this alert in commercial settings; furthermore, software updates, support, and new analytics might be required for on-farm application to implement these types of alerts.

Chloride and lactate as prognostic indicators of calf diarrhea from eighty-nine cases

IMPORTANCE

Deaths due to neonatal calf diarrhea are still one of the most critical problems of cattle breeding worldwide. Determining the parameters that can predict diarrhea-related deaths in calves is especially important in terms of prognosis and treatment strategies for the disease.

OBJECTIVE

The primary purpose of this study was to determine mortality rates and durations, survival status, and predictive prognosis parameters based on vital signs, hematology, and blood gas analyses in neonatal diarrheic calves.

METHODS

The hospital automation system retrospectively obtained data from 89 neonatal diarrheic calves.

RESULTS

It was found that 42.7% (38/89) of the calves brought with the complaint of diarrhea died during hospitalization or after discharge. Short-term and long-term fatalities were a median of 9.25 hours and a median of 51.50 hours, respectively. When the data obtained from this study is evaluated, body temperature (°C), pH, base excess (mmol/L), and sodium bicarbonate (mmol/L) parameters were found to be lower, and hemoglobin (g/dL), hematocrit (%), lactate (mmol/L), chloride (mmol/L), sodium (mmol/L) and anion gap (mmol/L) parameters were found to be higher in dead calves compared to survivors. Accordingly, hypothermia, metabolic acidosis, and dehydration findings were seen as clinical conditions that should be considered. Logistic regression analysis showed that lactate (odds ratio, 1.429) and CI- (odds ratio, 1.232) concentration were significant risk factors associated with death in calves with diarrhea.

CONCLUSIONS AND RELEVANCE

According to the findings obtained from this study, the determination of lactate and Cl- levels can be used as an adjunctive supplementary test in distinguishing calves with diarrhea with a good prognosis.

Bayesian evaluation of sensitivity and specificity of blood culture media and hypoglycemia in sepsis-suspected calves

BACKGROUND

Sepsis is a life-threatening condition for which critically important antimicrobials are often indicated. The value of blood culture for sepsis is indisputable, but appropriate guidelines on sampling and interpretation are currently lacking in cattle.

OBJECTIVE

Compare the diagnostic accuracy of 2 blood culture media (pediatric plus [PP] and plus aerobic [PA]) and hypoglycemia for bacteremia detection. Estimate the contamination risk of blood cultures in critically ill calves.

ANIMALS

One hundred twenty-six critically ill calves, 0 to 114 days.

METHODS

Retrospective cross-sectional study in which the performance of PP, PA and hypoglycemia to diagnose sepsis was assessed using a Bayesian latent class model. A Cox proportional hazards model was used to compare time to positivity (TTP). Potential contamination was descriptively analyzed. Isolates were considered relevant when they were; member of the Enterobacterales, isolated from both blood cultures vials, or well-known, significant bovine pathogens.

RESULTS

The sensitivities for PP, PA, and hypoglycemia were higher when excluding assumed contaminants; 68.7% (95% credibility interval = 30.5%-93.7%), 87.5% (47.0%-99.5%), and 61.3% (49.7%-72.4%), respectively. Specificity was estimated at 95.1% (82.2%-99.7%), 94.2% (80.7%-99.7%), and 72.4% (64.6%-79.6%), respectively. Out of 121 interpretable samples, 14.9% grew a presumed contaminant in PA, PP, or both. There was no significant difference in the TTP between PA and PP.

CONCLUSIONS AND CLINICAL IMPORTANCE

PA and PP appear to outperform hypoglycemia as diagnostic tests for sepsis. PA seems most sensitive, but a larger sample size is required to verify this. Accuracy increased greatly after excluding assumed contaminants. The type of culture did not influence TTP or the contamination rate.

Immunophenotyping of peripheral circulating lymphocytes and serum selenium levels in calves with neonatal diarrhea

This work aims to: (1) elucidate the immune response exhibited by CD4 + and CD8 + T lymphocyte cells in response to various infectious agents in calves suffering with neonatal diarrhea; and (2) determine and investigate the association between serum selenium levels and T lymphocyte subtypes in neonatal calves afflicted with neonatal diarrhea and infected with various infectious agents. The study encompassed a cohort of 50 calves, encompassing both sexes and various breeds, within the neonatal age range (1-28 days old). Subdivided into distinct groups, the calves were categorized based on the causative agents of neonatal diarrhea, including Rotavirus (n = 10), Cryptosporidium parvum (C.parvum) (n = 10), Coronavirus (n = 5), Rotavirus+C.parvum (n = 5), and a Control group (n = 20). Blood samples were meticulously obtained from the vena jugularis of all animals utilizing specific techniques-8 ml in tubes devoid of anticoagulant and 3 ml in blood collection tubes containing EDTA. Serum selenium levels were analyzed by ICP-MS. Flow Cytometry device was used to determine CD4 + and CD8 +T lymphocyte levels. In this study, although there was no statistically significant difference in serum selenium levels between all study groups, it was found that the selenium level in the control group was not sufficient. CD4 T lymphocyte levels, the rotavirus+C.parvum group exhibited a statistically significant elevation compared to the coronavirus group. Regarding CD8 + T lymphocyte levels, the coronavirus group demonstrated a statistically significant increase when compared to the control group. In intragroup analyses of CD8 + T lymphocyte levels, the coronavirus group exhibited a significant elevation compared to the rotavirus group, C.parvum group, and the C.parvum + Rotavirus group. A significant negative correlation was detected between selenium levels and CD4 + T lymphocytes, while no correlation was found between CD8 + T lymphocytes. Fibrinogen concentration exhibited statistical significance, being higher in the Rotavirus group (p < 0.008) compared to the control group, in the C.parvum group (p < 0.004) compared to the control group, and in the Coronavirus group (p < 0.001) compared to the control group. The leukocyte count demonstrated statistical significance, being higher in the Rotavirus group compared to the control group (p < 0.001), in the Rotavirus+C.parvum group compared to the control group (p < 0.002), and in the Coronavirus group compared to the control group (p < 0.011). In conclusion, the data derived from this study illuminate discernible disparities in CD4 + and CD8 + T lymphocyte immune responses, contingent upon the specific etiological agent associated with neonatal diarrhea. Furthermore, the study underscores the importance of considering selenium deficiency as a relevant factor in calves affected by neonatal diarrhea.

Activity behaviors and relative changes in activity patterns recorded by precision technology were associated with diarrhea status in individually housed calves

The objective of this case-control study was to quantify any association of daily activity behaviors and relative changes in activity patterns (lying time, lying bouts, step count, activity index) with diarrhea status in preweaning dairy calves. Individually housed calves sourced from auction were health-scored daily for signs of diarrhea (fecal consistency loose or watery for 2 consecutive days) for the 28 d after arrival. Calves with diarrhea were pair-matched with healthy controls (n = 13, matched by arrival date, arrival weight, and diagnosis days to diarrheic calves). Mixed linear regression models were used to evaluate the association of diarrhea status, and the diarrhea status by day interaction with activity behaviors (d -3 to d 4) and relative changes in activity patterns (d -3 to d 4) relative to diagnosis of a diarrhea bout. The serum Brix percentage at arrival and daily temperature-humidity index from the calf barn were explored as quantitative covariates, with day as a repeated measure. The baseline for relative changes in activity patterns was set at 100% on d 0. Diarrheic calves were less active; they averaged fewer steps (119.1 ± 18.81 steps/d) than healthy calves (227.4 ± 18.81 steps/d, LSM ± SEM). Diarrheic calves also averaged lower activity indices (827.34 ± 93.092 daily index) than healthy calves (1,396.32 ± 93.092 daily index). We also found also a diarrhea status by day interaction for lying time on d -3, with diarrheic calves spending more time lying (20.80 ± 0.300 h/d) than healthy calves (19.25 ± 0.300 h/d). For relative changes in activity patterns, a diarrhea status by day interaction was detectable on d -2, where diarrheic calves had greater relative changes in step counts (diarrhea 634.85 ± 87.581% vs. healthy 216.51 ± 87.581%) and activity index (diarrhea 316.83 ± 35.692% vs. healthy 150.68 ± 35.692%). Lying bouts were not associated with diarrhea status. These results show that diarrheic calves were more lethargic, and they had relative changes in activity patterns 2 d before clinical signs of diarrhea. Future research should explore the potential of an activity alert that positively indicates an individually housed calf at risk for a diarrhea bout using deviations from relative changes in individual calf activity patterns.

Association of the type of metabolic acidosis and non-survival of horses with colitis

Background

Metabolic acidosis (MA) is the most common acid-base disorder reported in horses with colitis but its association with survival is yet to be determined.

Objective

Investigate the types of MA in horses with colitis to determine effects of various anions on fatality rates.

Animals and procedures

We studied 158 horses with colitis. Horses were classified into 4 groups depending on the anion contributing to MA: i) no MA, ii) lactic acidosis (LA), iii) unmeasured strong ion (USI) acidosis, and iv) hyperchloremic acidosis (HA).

Results

Sixty percent (95/158) of horses had no MA, 22% (34/158) had LA, 12% (19/158) had HA, and 6% (10/158) had USI acidosis. The fatality rate of horses without MA was 20% (20/95), whereas the rates for those with LA, USI, and HA were 53% (18/34), 30% (3/10), and 16% (3/19), respectively. Horses with LA were more likely to die or be euthanized than horses without MA (OR: 4.2, 95% CI: 1.83 to 9.72, P < 0.001) and HA (OR: 5.9, 95% CI: 1.47 to 24.4, P < 0.01).

Conclusion and clinical relevance

Lactic acidosis was the most common type of MA in horses with colitis, and it was associated with non-survival.

Prognostic potential of inflammatory markers, oxidative status, thrombocyte indices, and renal biochemical markers in neonatal calf diarrhoea-induced systemic inflammatory response syndrome

The study aimed to assess the prognostic value of inflammatory markers, indicators of oxidative stress, thrombocyte indices, and renal biochemical markers in neonatal calf diarrhoea (NCD) induced by systemic inflammatory response syndrome (SIRS) upon admission. A prospective, observational, and case-control study was conducted on 56 calves diagnosed with NCD. Mean concentrations of interleukin-6 (IL-6), malondialdehyde (MDA), glutathione (GSH), mean platelet volume (MPV), platelet distribution width (PDW), blood urea nitrogen (BUN), and creatinine (Crea) were measured. Furthermore, the neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) were also calculated for SIRS survivors [SIRS (survivor)] and non-survivors [SIRS (non-survivor)] induced by NCD. A prognostic cut-off value for predicting the prognosis of the SIRS's induced by NCD was obtained via receiver operating characteristic (ROC) curve analysis. Upon admission, the SIRS (non-survivor) calves had significantly higher (P < .001) average levels of IL-6, MDA, BUN, Crea, MPV, and PDW compared to the SIRS (survivor) calves and significantly lower (P < .001) average levels of GSH. Despite an apparent increase in the NLR and PLR values of calves diagnosed with SIRS, no significant difference was found between the survival and non-survivor SIRS cases. Positive predictive values (PPVs) for survival were determined as 100 %, 100 %, 80 %, 100 %, 80 %, and 80 %, respectively, using cut-off values of IL-6 (≤259.67 ng/L), MDA (≤2.87 nmol/mL), MPV (≤12.5 fL), PDW (≤34.25 %), BUN (≤168.3 mg/dL), and Crea (≤2.11 mg/dL). The determined threshold values are those obtained upon admission to the hospital. Based on the sensitivity, specificity, and PPVs derived from the ROC analysis, it has been concluded that IL-6, MDA, MPV, PDW, BUN, and Crea are the most relevant biomarkers used for predicting the prognosis of NCD-induced SIRS in calves. Furthermore, it is also noteworthy that IL-6 exhibited the highest effectiveness among all biomarkers.

Surveilling brain damage using brain biomarkers in hypoglycemic neonatal calves with diarrhea

Hypoglycemia is a condition associated with neonatal diarrhea in calves, leading to increased mortality and neurological clinical signs. The aim of the present study was to determine the development of brain damage in hypoglycemic calves with neonatal diarrhea and the diagnostic and prognostic significance of these biomarkers. Ten healthy and 50 hypoglycemic calves with diarrhea were included in the study. Clinical examination, blood gases and complete blood count were performed at admission. Blood serum calcium-binding protein B (S100B), neuron-specific enolase (NSE), glial fibrillary acidic protein (GFAP), ubiquitin carboxyl-terminal hydrolysis isoenzyme-1 (UCHL-1), activitin A (ACT), adrenomodullin (AM) concentrations, and creatine kinase-BB (CK-BB) enzyme activity were measured using commercial bovine-specific ELISA kits to assess brain damage. Of the hypoglycemic calves enrolled in the study, 13 (26%) survived and 37 (74%) died. In addition, 32 (64%) of the calves had severe acidosis and 24 (48%) had sepsis. S100B, GFAP, UCHL-1, CK-BB (p < 0.001) and NSE (p < 0.05) concentrations were significantly higher in hypoglycemic calves compared to healthy calves, while ACT concentrations were lower. Blood glucose concentration was negatively correlated with serum S100B, GFAP, UCHL-1, and CK-BB enzyme activity and positively correlated with ACT in hypoglycemic calves (p < 0.01). Brain injury biomarkers were not predictive of mortality (p > 0.05). Morever, severe hypoglycemia, severe acidosis and sepsis variables were not found to have sufficient capacity to predict mortality when considered alone or together (p > 0.05). In conclusion, brain damage may develop as a consequence of hypoglycemia in calves. S100B, NSE, GFAP, UCHL-1, ACT, and CK-BB concentrations can be used to diagnose brain damage in hypoglycemic calves. However, the variables of severe hypoglycemia, severe acidosis, and sepsis together with the biomarkers of brain injury have a limited value in predicting the prognosis of neonatal calves with diarrhea.

Role of maternal variables on the development of neonatal hypoglycaemia and influence of neonatal hypoglycaemia on performance of goat kids

The study evaluated the influence of maternal variables (age, body weight and body mass index; BMI) during mating on the development of hypoglycaemia and investigated whether hypoglycaemia at birth impairs thermoregulation, metabolism, body weight gain and immunoglobulin concentration in neonatal goat kids. Post-kidding, the kids born with hypoglycaemia (n = 19) and normoglycaemia (n = 19) were immediately identified and postnatal blood samples, body weight and cardinal physiological variables were determined. Results revealed no significant (P < 0.05) difference in pre-mating maternal variables between dams that kidded hypoglycaemic and normoglycaemic kids. Kids born with hypoglycaemia had lower (P <0.05) blood glucose concentration from birth, until Day 2, when values became comparable between the two groups. Afternoon respiratory and pulse rates were markedly (P < 0.05) unstable in kids born with hypoglycaemia and the early postnatal rise (P < 0.05) in morning rectal temperature in both groups was accompanied by a decrease (P < 0.05) on day 20 in kids born with hypoglycaemia. Blood cholesterol and triglyceride concentrations were lower (P < 0.05) in hypoglycaemic kids and the normoglycaemic kids showed marked increase (P < 0.05) in circulating immunoglobulin concentration 24 h after birth, while age had no (P > 0.05) effect in hypoglycaemic kids. A more pronounced decrease (P < 0.05) in weekly weight gain was observed in hypoglycaemic kids. It was concluded that neonatal goat kids born with hypoglycaemia may have compromised thermoregulation, metabolism and body weight gain, and the cause of hypoglycaemia in kids may not be related to pre-mating maternal variables.

Effectiveness of oral electrolyte solutions with different compositions for the treatment of neonatal calves with induced osmotic diarrhea

ABSTRACT In a randomized controlled trial, we evaluated the effects of five oral electrolyte solutions (OESs) with different compositions of water, electrolyte, and acid-base balances of diarrheal neonatal calves. Osmotic diarrhea and dehydration were induced with sucrose in milk, spironolactone, and hydrochlorothiazide for 48 h in thirty 10-day old Holstein healthy calves with 43.5 ± 3.80 kg BW who were fed with natural milk. They were allocated to five treatment groups (n=6) based on the administered OES (commercial: OES A, B, C, D; and non-commercial: OES UEL). On the day of treatment, the calves received 6L of OES in two doses apart from milk intakes. Venous blood samples were collected at -48h (start of induction), -24h, 0h (start of the treatment day), 8h, 16h, 24h, 48h, and 72h. TPP, glucose, D-lactate, L-lactate, pH, pCO2, HCO3 -, BE, Na+, K+, Cl-, SID3, SIG, AG, Atot and percentage change in plasma volume (%PV) were measured or calculated and analyzed by two-way repeated measures ANOVA. All the calves developed osmotic diarrhea, mild to moderate dehydration, hyponatremia, relative hyperchloremia, and moderate to severe metabolic acidosis. The tested OESs were well accepted by the calves and effective in reversing dehydration, electrolyte imbalances, and metabolic acidosis. OES D did not completely correct hyponatremia, and SEO B caused transient hyperglycemia. It has been concluded that all the tested OESs are safe and effective for the treatment of diarrhea in calves with moderate degrees of dehydration and metabolic acidosis, which indicates that they have proper compositions for this purpose.

Sepsis and survival in critically ill calves: Risk factors and antimicrobial use

BACKGROUND

Sepsis is a life-threatening disease for which critically important antimicrobials (CIA) frequently are used. Diagnostic and therapeutic guidelines for sepsis and critically ill calves are largely lacking.

OBJECTIVES

Identify factors associated with mortality in critically ill calves and describe bacteria obtained from blood cultures of critically ill calves with sepsis and their antimicrobial resistance.

ANIMALS

Two-hundred thirty critically ill calves, mainly Belgian Blue beef cattle.

METHODS

Retrospective cohort study. Logistic regression, survival analysis, and decision tree analysis were used to determine factors associated with mortality.

RESULTS

Of the critically ill calves, 34.3% had sepsis and 61.3% died. The final survival model indicated that calves with sepsis (hazard risk [HR]: 1.6; 95% confidence interval [CI]: 1.0-2.5; P = .05), abnormal behavior (HR: 2.3; 95% CI: 1.3-4.0; P = .005), and hypothermia (HR: 0.82; 95% CI: 0.72-0.95; P = .01) had a significantly higher mortality risk. In a second survival model, hypothermia (HR: 0.87; 95% CI: 0.78-0.96; P = .004) and hypoglycemia (HR: 2.2; 95% CI: 1.5-3.3; P < .001) were risk factors for mortality. Decision tree analysis emphasized the importance of behavior, hypochloremia, hypoglycemia, hyperkalemia, and lung ultrasonography for mortality risk. Escherichia coli (30.6%) was most frequently isolated from blood cultures, of which 90.9% were multidrug resistant. Inappropriate use of antimicrobials was frequent for penicillin, amoxicillin, and sulfamethoxazole/trimethoprim, but less for CIA.

CONCLUSIONS AND CLINICAL IMPORTANCE

Many critically ill calves have sepsis, which increases mortality risk. Bacteria involved are often resistant to first-intention antimicrobials but less resistant to CIA. The other identified risk factors for mortality can support therapeutic decision-making.

Evaluation of a point-of-care meter for measuring glucose concentrations in dairy calves: A diagnostic accuracy study

The objective of this cross-sectional, diagnostic accuracy study was to validate a human blood glucose meter (Contour Next One Meter, Ascensia Diabetes Care) for accuracy and precision when measuring blood glucose, and for diagnostic accuracy for hypoglycemic status in dairy calves using whole blood and blood plasma. A total of 49 male dairy calves [body weight (BW): 46.3 ± 0.8 kg] had jugular catheters placed within 75 min after birth. Thereafter, blood was withdrawn from the catheter at specific time points (-10, 10, 20, 30, 45, 60, 90, 120, 180, 240, 360, 480, and 600 min) relative to the first and second colostrum feedings (2 h 15 min and 14 h 5 min postnatal; feeding rate: 7% of BW wt/wt). The reference standard method for plasma glucose concentration was determined colorimetrically and in duplicate using the glucose oxidase-peroxidase reaction. Data were assessed for agreement between the glucose meter and the reference standard using Lin's concordance correlation coefficients (CCC), coefficients of determination (precision), and Bland-Altman plots. In addition, a mixed linear regression model was built using the reference method as the outcome, with the glucose meter and repeated measures of time as the explanatory variables and calf as a random effect. The sensitivity (Se), specificity (Sp), and area under the curve (AUC) for the glucose meter using calf whole-blood and plasma were calculated at a threshold of <4.44 mmol/L to determine hypoglycemia. The precision (CCC = 0.95, R2 = 0.93) and accuracy (AUC = 0.98) of the glucose meter were very high when used on 1,303 blood plasma samples. Youden's index revealed a threshold of <4.45 mmol/L for the glucose meter when used with plasma, leading to Se of 94.2% and Sp of 91.9%, with 92.5% of samples being correctly classified, suggesting high diagnostic accuracy. When using whole blood, precision (CCC = 0.85 and R2 = 0.73) and accuracy (AUC = 0.92) were high when used on 476 samples. Youden's index revealed a threshold of <4.95 mmol/L for the glucose meter when used with whole calf blood, leading to Se of 95.6% and Sp of 80.3%, with 84.7% of samples being correctly classified, suggesting high diagnostic accuracy for use on farm. In summary, this glucose meter was validated for measuring calf blood glucose using both plasma and whole blood. This meter can measure glycemic status in calves and may be useful for clinical and on-farm use to make intervention decisions.

Serum haptoglobin concentration and liver enzyme activity as indicators of systemic inflammatory response syndrome and survival of sick calves

Background

Increased concentration of haptoglobin (Hp) in serum is associated with survival of critically ill humans and horses. High serum activity of liver‐derived enzyme is associated with sepsis in children and foals.

Hypothesis/Objectives

Investigate whether admission serum Hp and glutamic dehydrogenase (GLDH) are associated with systemic inflammatory response syndrome (SIRS) and survival of sick calves.

Animals

One hundred two calves.

Methods

Retrospective cross‐sectional study. Electronic medical records from all calves <30 days of age admitted to a teaching hospital for 8 years were reviewed. The signalment, clinicopathological findings, the presence of SIRS, final diagnosis, hospitalization time and outcome were recorded. A Cox proportional hazard ratio (HzR) were calculated to assess the association between clinicopathological variables and survival to discharge.

Results

Serum Hp concentrations were similar between SIRS (0.29 g/L; range, 0.05‐3.6) and non‐SIRS calves (0.22 g/L; range, 0‐4.2; P = .62). GLDH activity was similar between SIRS (12 U/L; range, 1‐1025) and non‐SIRS calves (9 U/L; range, 2‐137; P = .2). Absent suckle reflex (HzR: 6.44, 95% CI: 1.44‐28.86), heart rate (HR) < 100 beats per minute (bpm; HzR: 12.2; 95% CI: 2.54‐58.62), HR > 140 bpm (HzR: 3.59, 95% CI: 1.05‐12.33), neutrophil count <1.7 × 10⁹/L (HzR: 7.36; 95% CI: 2.03‐26.66) and increased gamma‐glutamyl transferase activity (every 50‐unit, HzR: 1.12; 95% CI: 1.03‐1.21) were predictive of nonsurvival.

Conclusions and Clinical Importance

The use of Hp and GLDH for prediction of survival in sick calves cannot be recommended at this time.

Associations between Feeding Behaviors Collected from an Automated Milk Feeder and Neonatal Calf Diarrhea in Group Housed Dairy Calves: A Case-Control Study

Simple Summary

Precision technology devices are often integrated on dairies to monitor animal health. One precision technology used to manage calves is an automated milk feeder which can record feeding behaviors such as daily milk intake, drinking speed, and feeder visits. The objective of this study was to determine if calf feeding behaviors collected by an automated milk feeder, changed in the days surrounding diagnosis of neonatal calf diarrhea (NCD; e.g., −3 days to 5 days after diagnosis). Milk intake was lower for the greatest number of days surrounding diagnosis of NCD compared to control calves, but the sensitivity and specificity of detecting NCD using any individual behavior was low. However, parallel testing using cumulative feeding behaviors on the day of diagnosis of NCD increased the sensitivity for detecting disease. This study provides insights into the association of feeding behavior with calves destined for NCD using an automated milk feeder. We suggest feeding behaviors cannot replace visual diagnosis of NCD, but that feeding behaviors might serve as a screening tool for producers.

Abstract

The objective of this case-control study was to determine if feeding behavior data collected from an automated milk feeder (AMF) could be used to predict neonatal calf diarrhea (NCD) in the days surrounding diagnosis in pre-weaned group housed dairy calves. Data were collected from two research farms in Ontario between 2017 and 2020 where calves fed using an AMF were health scored daily and feeding behavior data (milk intake (mL/d), drinking speed (mL/min), number of rewarded or unrewarded visits) was collected. Calves with NCD were pair matched to healthy controls (31 pairs) by farm, gender, and age at case diagnosis to assess for differences in feeding behavior between case and control calves. Calves were first diagnosed with NCD on day 0, and a NCD case was defined as calves with a fecal score of ≥2 for 2 consecutive days, where control calves remained healthy. Repeated measure mixed linear regression models were used to determine if there were differences between case and control calves in their daily AMF feeding behavior data in the days surrounding diagnosis of NCD (−3 to +5 days). Calves with NCD consumed less milk on day 0, day 1, day 3, day 4 and day 5 following diagnosis compared to control calves. Calves with NCD also had fewer rewarded visits to the AMF on day −1, and day 0 compared to control calves. However, while there was a NCD status x day interaction for unrewarded visits, there was only a tendency for differences between NCD and control calves on day 0. In this study, feeding behaviors were not clinically useful to make diagnosis of NCD due to insufficient diagnostic ability. However, feeding behaviors are a useful screening tool for producers to identify calves requiring further attention.

Additive prognostic value of preoperative plasma glucose concentrations in calves undergoing abdominal surgery

Surgical abdominal emergencies in calves are associated with a guarded prognosis, especially if neonates are affected. Because hypoglycemia has been associated with sepsis and endotoxemia, this study aimed to assess the prognostic relevance of preoperative plasma glucose concentrations (GLUC) in calves requiring surgery for an acute abdominal disorder. For this purpose, data from retrospective and prospective case series were analyzed, consisting of 586 and 83 hospitalized calves, respectively. The outcomes of calves were evaluated until hospital discharge (both study populations) and for 3 mo following discharge by a phone call to the farmer (prospective study population). For the retrospective study population, the overall survival rate was 31.2%. Calves with a negative outcome (NO) had significantly lower median GLUC (4.3 mmol/L) than calves with a positive outcome (PO; 5.0 mmol/L). The survival rates of calves with GLUC <2.4 mmol/L and 2.4 to 3.1 mmol/L were 3.6 and 8.3%, respectively. The inclusion of GLUC improved a previous prognostic model based on plasma l-lactate concentration and age. The resulting analyses indicated that NO was associated with low age (<7 d), hyper-l-lactatemia (>8.84 mmol/L), and GLUC <4.4 mmol/L (age 7-20 d) and <3.3 mmol/L (age ≥21 d), respectively. The area under the receiver operating characteristic curve of this model was 0.79 (95% confidence interval: 0.76-0.83) and the resulting sensitivity and specificity for NO at the optimal probability cut-point of 0.69 were 66.7 and 85.8%, respectively. For the prospective study population, the established model had sensitivity and specificity for predicting NO after 3 mo (proportion 24%) of 61.9 and 85%, respectively. In both study populations, hypoglycemia was significantly associated with intraoperative evidence of a septic process within the abdominal cavity. The present analyses show that hypoglycemia was highly indicative of a poor prognosis and serious intraoperative findings such as peritonitis. Determination of GLUC should therefore be part of the diagnostic work-up in calves suffering from an acute abdominal emergency.

Gut Microbiota and Their Role in Health and Metabolic Disease of Dairy Cow

Ruminants are mostly herbivorous animals that employ rumen fermentation for the digestion of feed materials, including dairy cows. Ruminants consume plant fibre as their regular diet, but lack the machinery for their digestion. For this reason, ruminants maintain a symbiotic relation with microorganisms that are capable of producing enzymes to degrade plant polymers. Various species of microflora including bacteria, protozoa, fungi, archaea, and bacteriophages are hosted at distinct concentrations for accomplishing complete digestion. The ingested feed is digested at a defined stratum. The polysaccharic plant fibrils are degraded by cellulolytic bacteria, and the substrate formed is acted upon by other bacteria. This sequential degradative mechanism forms the base of complete digestion as well as harvesting energy from the ingested feed. The composition of microbiota readily gets tuned to the changes in the feed habits of the dairy cow. The overall energy production as well as digestion is decided by the intactness of the resident communal flora. Disturbances in the homogeneity gastrointestinal microflora has severe effects on the digestive system and various other organs. This disharmony in communal relationship also causes various metabolic disorders. The dominance of methanogens sometimes lead to bloating, and high sugar feed culminates in ruminal acidosis. Likewise, disruptive microfloral constitution also ignites reticuloperitonitis, ulcers, diarrhoea, etc. The role of symbiotic microflora in the occurrence and progress of a few important metabolic diseases are discussed in this review. Future studies in multiomics provides platform to determine the physiological and phenotypical upgradation of dairy cow for milk production.

Prevalence of disorders in preweaned dairy calves from 731 dairies in Germany: A cross-sectional study

The objective of this cross-sectional study was to determine the prevalence of disorders in preweaned calves in 3 regions in Germany, exemplary for structural diversity in dairy farming. A farm visit was performed on a single occasion on 731 dairy farms in the northern, eastern, and southern regions of Germany between December 2016 and July 2019. Farms differed in herd size, geographical location, and management. In the northern region, the farms had a median of 90 milking cows and were often run as full-time family businesses, partly with external workers. The eastern region tended to have larger farms (a median of 251 milking cows), which were often large-scale agricultural enterprises with employees. In the southern region, the farms had a median of 39 milking cows and were often traditional family businesses, some of these being part-time businesses. Clinical examinations were performed on 14,164 preweaned dairy calves (median 12 calves per farm) by trained veterinarians. A complete data set was available for 13,656 calves. Almost half (42.0%) of the evaluated calves were classified as being affected by at least 1 of the common calf disorders. Omphalitis (O, 20.9%; n = 2,876) and diarrhea (D, 18.5%; n = 2,670) were the most frequently recorded diagnoses, whereas respiratory diseases (RD) were observed to a lesser extent (8.7%; n = 1,100). A striking feature was the fact that 7.1% (n = 987) of the calves were affected by more than 1 disorder at the same time (multimorbidity, M). The following combinations of disorders were frequently observed: O and D (n = 596), O and RD (n = 164), and D and RD (n = 140). Disorders such as O and D, as well as M, were predominantly observed in calves aged 2 wk. A gradual increase in the frequency of RD was observed with age. For all disorders except RD, male calves were more often affected than females. Omphalitis was predominantly diagnosed in the summer months, whereas RD, D, and M were more common in the fall. We detected several statistically significant differences in the prevalence of clinical signs and disorders in preweaned dairy calves between the 3 exemplary regions. The prevalence of RD was higher in the south (10.8%) than in the north (8.2%) and east (7.4%). In the north (33.2%), O was observed more frequently than in the other regions (east: 18.9%; south: 10.5%), whereas D was found less frequently in the north (13.8%) than in the east (21.6%) and south (20.0%).

Investigation of neonatal disorders in New World camelids and factors associated with death during and after hospitalization of affected crias

OBJECTIVE

To assess signalment, clinical findings, and treatments for New World camelids (NWCs) hospitalized for evaluation and treatment of neonatal disorders and investigate associations between these factors and death during and after hospitalization.

ANIMALS

267 NWCs ≤ 30 days of age.

PROCEDURES

Medical records of a veterinary teaching hospital were retrospectively reviewed to identify NWCs admitted for evaluation and treatment of neonatal disorders between 2000 and 2010. Signalment, physical examination data, diagnostic findings, treatments, and outcomes were recorded. Factors were examined for association with death during hospitalization and the overall hazard of death by use of multivariable logistic regression and Cox proportional hazards analysis, respectively.

RESULTS

The sample comprised alpacas (n = 255) and llamas (12). Median age at admission was 3 days, and median hospitalization time was 2 days; 208 of the 267 (77.9%) neonatal NWCs survived to hospital discharge. Factors associated with increased odds of death during hospitalization included prematurity or dysmaturity, hypothermia, sepsis, toxic changes in neutrophils, and undergoing surgery. The odds of death during hospitalization also increased as anion gap increased. After discharge, 151 of 176 (85.8%) animals had follow-up information available (median follow-up time, 2,932 days); 126 (83%) were alive and 25 (17%) had died. Prematurity or dysmaturity, congenital defects, sepsis, oxygen administration, and undergoing surgery as a neonate were associated with an increased hazard of death; the hazard of death also increased as serum chloride concentration at the time of hospitalization increased.

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggested the prognosis for survival during and after hospitalization is good for most NWCs hospitalized because of neonatal disorders.

Intravenous and Oral Fluid Therapy in Neonatal Calves With Diarrhea or Sepsis and in Adult Cattle

Optimal fluid therapy protocols in neonatal calves and adult cattle are based on consideration of signalment, history, and physical examination findings, and individually tailored whenever laboratory analysis is available. Measurement of the magnitude of eye recession, duration of skin tenting in the lateral neck region, and urine specific gravity by refractometry provide the best estimates of hydration status in calves and cattle. Intravenous and oral electrolyte solutions (OES) are frequently administered to critically ill calves and adult cattle. Application of physicochemical principles indicates that 0.9% NaCl, Ringer's solution, and 5% dextrose are equally acidifying, lactated Ringer's and acetated Ringer's solution are neutral to mildly acidifying, and 1.3-1.4% sodium bicarbonate solutions are strongly alkalinizing in cattle. Four different crystalloid solutions are recommended for intravenous fluid therapy in dehydrated or septic calves and dehydrated adult cattle: (1) lactated Ringer's solution and acetated Ringer's solution for dehydrated calves, although neither solution is optimized for administration to neonatal calves or adult cattle; (2) isotonic (1.3%) or hypertonic (5.0 or 8.4%) solutions of sodium bicarbonate for the treatment of calves with diarrhea and severe strong ion (metabolic) acidosis and hyponatremia, and adult cattle with acute ruminal acidosis; (3) Ringer's solution for the treatment of metabolic alkalosis in dehydrated adult cattle, particularly lactating dairy cattle; and (4) hypertonic NaCl solutions (7.2%) and an oral electrolyte solution or water load for the rapid resuscitation of dehydrated neonatal calves and adult cattle. Much progress has been made since the 1970's in identifying important attributes of an OES for diarrheic calves. Important components of an OES for neonatal calves are osmolality, sodium concentration, the effective SID that reflects the concentration of alkalinizing agents, and the energy content. The last three factors are intimately tied to the OES osmolality and the abomasal emptying rate, and therefore the rate of sodium delivery to the small intestine and ultimately the rate of resuscitation. An important need in fluid and electrolyte therapy for adult ruminants is formulation of a practical, effective, and inexpensive OES.

Dependence of the apparent bicarbonate space on initial plasma bicarbonate concentration and carbon dioxide tension in neonatal calves with diarrhea, acidemia, and metabolic acidosis

BACKGROUND

Marked strong ion (metabolic) acidosis in neonatal diarrheic calves usually is corrected by IV administration of NaHCO₃ . The distribution space for IV-administered bicarbonate, called the apparent bicarbonate space (ABS), appears to depend on initial plasma bicarbonate concentration (cHCO₃ ) and varies considerably in calves.

OBJECTIVE

To determine whether ABS was associated with initial plasma cHCO₃ and other acid-base variables.

ANIMALS

Twenty-five neonatal diarrheic calves with acidemia and metabolic acidosis.

METHODS

Prospective observational study using a convenience sample. Calves received NaHCO₃ (10 mmol/kg) and glucose (1.4 mmol/kg) IV in a crystalloid solution at 25 mL/kg over 60 minutes. The ABS (L/kg) was calculated at 4 time points over 2 hours after the end of the infusion. The relationship between ABS and initial acid-base variables was characterized using nonlinear, linear, and stepwise regression.

RESULTS

The median value for ABS calculated from the initial plasma cHCO₃ increased from 0.53 L/kg (range, 0.40-0.79) at the end of IV infusion to 0.96 L/kg (range, 0.54-1.23) 120 minutes later. Data obtained at the end of infusion provided the best fit to initial plasma cHCO₃ and jugular venous blood Pco₂ , such that: ABS = 0.41 + 1.06/cHCO₃ and ABS = 0.87-0.0082 × Pco₂ .

CONCLUSIONS AND CLINICAL IMPORTANCE

The observed median value for ABS of 0.53 L/kg in our study was similar to the empirically used value of 0.6. However, ABS values varied widely and were increased in calves with severe metabolic acidosis. We therefore recommend calculating ABS using the initial plasma cHCO₃ or venous blood Pco₂ , if respective measurements are available.

Acid-base disorders in sick goats and their association with mortality: A simplified strong ion difference approach

OBJECTIVES

To investigate the acid-base status of sick goats using the simplified strong ion difference (sSID) approach, to establish the quantitative contribution of sSID variables to changes in blood pH and HCO3 - and to determine whether clinical, acid-base, and biochemical variables on admission are associated with the mortality of sick goats.

ANIMALS

One hundred forty-three sick goats.

METHODS

Retrospective study. Calculated sSID variables included SID using 6 electrolytes unmeasured strong ions (USI) and the total nonvolatile buffer ion concentration in plasma (Atot ). The relationship between measured blood pH and HCO3 - , and the sSID variables was examined using forward stepwise linear regression. Cox proportional hazard models were constructed to assess associations between potential predictor variables and mortality of goats during hospitalization.

RESULTS

Hypocapnia, hypokalemia, hyperchloremia, hyperlactatemia, and hyperproteinemia were common abnormalities identified in sick goats. Respiratory alkalosis, strong ion acidosis, and Atot acidosis were acid-base disorders frequently encountered in sick goats. In sick goats, the sSID variables explained 97% and 100% of the changes in blood pH and HCO3 - , respectively. The results indicated that changes in the respiratory rate (<16 respirations per minute), USI, and pH at admission were associated with increased hazard of hospital mortality in sick goats.

CONCLUSIONS AND CLINICAL IMPORTANCE

The sSID approach is a useful methodology to quantify acid-base disorders in goats and to determine the mechanisms of their development. Clinicians should consider calculation of USI in sick goats as part of the battery of information required to establish prognosis.

Prognostic utility of pre- and postoperative plasma l-lactate measurements in hospitalized cows with acute abdominal emergencies

The aim of the present analyses was to compare the prognostic value of pre- and postoperative l-lactate measurements in hospitalized cows requiring surgical intervention for an acute abdominal emergency, such as gastrointestinal ileus or peritonitis. For this purpose, we analyzed data from retro- and prospective case series, consisting of 754 and 98 cows, respectively. Plasma l-lactate concentrations (L-LAC) were determined upon admission to the hospital (both study populations), immediately before initiation of surgical intervention (prospective study population), and 6, 12, 24, 48, and 72 h later (prospective study population). The outcome of cows was evaluated until hospital discharge (both study populations) and 3 mo after discharge by a phone call to the farmer (prospective study population). A negative outcome was defined as death or euthanasia during hospitalization, or if discharged animals had an unsatisfied owner or were culled for medical reasons that were directly related to the initial abdominal emergency. For the retrospective study population, the overall survival rate until hospital discharge was 66%. Cows with a negative outcome (median: 6.81 mmol/L) had significantly higher L-LAC than cows with a positive outcome (3.66 mmol/L) of therapy. At the individual diagnosis level, L-LAC was associated with mortality in cows with a diagnosis of abomasal volvulus, local peritonitis, hemorrhagic bowel syndrome, and jejunal volvulus. Considering the whole study population, the area under the receiver operating characteristic curve was 0.66. For the prospective study population, the proportion of cows with a positive outcome was 65% until hospital discharge and 61% after the 3-mo observation period. At all sampling times, before and during the first 12 h after surgical intervention, cows with a negative outcome had significantly higher L-LAC than cows with a positive outcome. The largest area under the receiver operating characteristic curve for L-LAC was observed at 6 h (0.89). A cut-point of 1.77 mmol/L was identified, which had a sensitivity and specificity for predicting a negative outcome until hospital discharge of 88.9 and 73.4%, respectively. The present analyses confirmed previous findings in calves and show that persistent hyper-l-lactatemia during the early postoperative period is a more reliable indicator for a negative outcome than hyper-l-lactatemia before initiation of surgical intervention.

Changes in fluid and acid-base status of diarrheic calves on different oral rehydration regimens

The administration of oral rehydration solutions (ORS) is an effective method to treat dehydration and acidosis in calves suffering from diarrhea. The ORS can be prepared in water or milk. The aim of the present study was to elucidate how fluid and acid-base balance change after feeding milk compared with ORS prepared in water or milk to diarrheic calves. Calves (n = 30) with naturally acquired diarrhea were sequentially assigned in a 2:1 ratio to the following pretreatments: milk and water-ORS (pretreatment 1; n = 20 calves) or milk-ORS (pretreatment 2; n = 10 calves), respectively. The assignment was done on the day of diarrhea diagnosis. On d 3 ± 1 following assignment to pretreatment group, and after a fasting period of 9 h, diarrheic calves were subjected to the following treatments: 2 L of milk (pretreatment 1; n = 10 calves), water-ORS (pretreatment 1; n = 10 calves), or milk-ORS (pretreatment 2; n = 10 calves). Blood samples were taken before and at several time points until 6 h after feeding. Plasma protein, osmolality, and electrolytes were determined and a blood gas analysis was performed. Change in plasma volume was calculated according to plasma protein, and water intake during the experimental period was recorded. Plasma volume was increased 30 min after feeding water-ORS or milk but the increase was less pronounced after feeding milk compared with water-ORS. After feeding milk-ORS, no significant increase in plasma volume could be detected. Because of the pretreatment, plasma osmolality was higher in calves fed milk-ORS, but no change in plasma osmolality after feeding was detected. No difference in water consumption between the treatment groups was noted within the observed 6-h period. The pH was increased after feeding milk-ORS, whereas water-ORS and milk-feeding did not increase pH in blood. Pretreatment with milk-ORS resulted in higher baseline d-lactate concentration, but feeding milk-ORS reduced d-lactate values after feeding. In calves with diarrhea, plasma volume increased more quickly and to a greater extent after feeding water-ORS; thus, we recommend treating diarrheic calves with water-ORS before supplying milk. Nevertheless, diarrheic calves need milk to fulfill their energy needs. The administration of ORS in milk combined with free water access is more advisable than feeding milk exclusively because milk has no alkalinizing ability and contains less sodium. However, the effects of milk-ORS feeding on d-lactate levels in diarrheic calves need further elucidation.

Clinical application of 2.16% hypertonic saline solution to correct the blood sodium concentration in diarrheic calves with hyponatremia

The aim of this study was to examine whether 2.16% hypertonic saline solution (HSS) is useful for the treatment of diarrheic calves with hyponatremia. Eleven of 13 female Holstein calves exhibiting moderate diarrhea and hyponatremia received 1,250 ml of 2.16% HSS over 15 min regardless of body weight. The remaining two calves that were unable to stand and had severe hyponatremia received 2,500 ml of 2.16% HSS intravenously over 30 min. As a result, hyponatremia in all diarrheic calves was significantly improved by the administration of 2.16% HSS from 122.2 ± 7.0 mEq/l at pre to 134.8 ± 3.7 mEq/l at post, which was above the threshold of 132 mEq/l for hyponatremia. Therefore, 2.16% HSS may be useful for hyponatremia in calves with diarrhea.

Evaluation of the Freestyle Optium Neo H point-of-care device for measuring blood glucose concentrations in sick calves

Background

Data on the performance of a glucometer in calves with different diseases are currently lacking.

Objective

The primary objective of this study was to evaluate the reliability of a point of care glucometer in calves affected by different diseases relative to a traditional bench‐top autoanalyzer.

Animals

One hundred ninety‐six calves with different disorders in a referral hospital.

Methods

Prospective study. Venous blood samples were used for the determination of glucose concentrations in blood and plasma using the Freestyle Optium Neo H and autoanalyzer, respectively. Data were subjected to Passing‐Bablok regression and Bland‐Altman plots. The Freestyle Optium Neo H was the test method and the autoanalyzer was the reference method. The diagnostic performance of the glucometer relative to the autoanalyzer was assessed using 3 different plasma glucose concentrations.

Results

The Passing‐Bablok regression for the glucometer against the reference method revealed the presence of both proportional bias (1.12; 95% confidence interval [CI], 1.07‐1.18) and constant bias (−11.25; 95% CI, −16.0 to −7.70). The glucometer yielded 92.2%‐100% sensitivity and 86.4%‐96% specificity for the assessing glucose concentration based on different concentration thresholds.

Conclusions and Clinical Importance

The Freestyle Optium Neo H showed proportional and constant biases relative to the reference method. The glucometer showed poor performance according to criteria recommended by the International Standards Organization and the American Society for Veterinary Clinical Pathology. However, the glucometer determined hypoglycemia with high sensitivity and specificity therefore it might be used to diagnose hypoglycemia in calves with different diseases until calf‐specific POC glucometers are developed.

Determining the predictive capability of a Clinical Assessment Scoring Chart to differentiate severity of the clinical consequences of neonatal calf diarrhea relative to gold-standard blood gas analysis

Neonatal calf diarrhea (NCD) is a major problem to calf health worldwide, in terms of both morbidity and mortality. A five-point ordinal scale clinical assessment scoring (CAS) chart was utilized to assess calves suffering from NCD-related clinical abnormalities (acidosis and dehydration) on commercial farms. The objective of this research was to determine the predictive capability of this CAS chart against gold standard blood gas parameters, designed to assist farmers in the accurate assessment of the clinical consequences of NCD. A total of 443 diarrheic and non-diarrheic calves were enrolled in the study. The CAS chart rated a calf’s health from no clinical signs to varying degrees of clinical severity on a 0 (clinically normal) to 4 (grave) scale, based on clinical indicators including calf demeanour, ear position, mobility, suckle reflex, desire-to-feed, and enophthalmos. Blood gas analysis was conducted for individual calves, consisting of pH, base excess, Na⁺, K⁺, Ca²⁺, Cl⁻, glucose, total hemoglobin, bicarbonate, anion gap, and strong ion difference. Statistical evaluation was performed by comparison of the CAS score with blood gas profiles using ordinal logistic regression and a non-parametric estimation of the Receiver Operating Characteristics (ROC). The ROC analysis indicated that the CAS chart had acceptable specificity (>95%) with low sensitivity (<60%) in differentiating clinically normal from acidotic/dehydrated cases. Assessment of individual severity classes indicated that the chart can predict and differentiate both clinically normal and advanced cases from the other severity classes (peak estimations >80%) but had reduced accuracy in differentiating mild and moderate cases (peak estimations >50%). The chart, as presented, provides a simple tool to differentiate clinically normal from calves suffering the consequences of diarrhea, but fails to accurately differentiate severity for NCD related acidosis and dehydration. Further efforts are required to enhance the sensitivity and differential diagnostic value of this type of chart.

Role of electrolyte abnormalities and unmeasured anions in the metabolic acid-base abnormalities in dogs with parvoviral enteritis

BACKGROUND

The strong ion model (SIM) is an alternative paradigm in the characterization of acid-base disturbances particularly in complex disorders.

HYPOTHESIS/OBJECTIVES

To compare the acid-base changes in dogs with parvoviral enteritis (PE) using the Henderson-Hasselbalch (HH) approach, with 2 strong ion approaches.

ANIMALS

Forty-four dogs with PE, and 16 age-matched control dogs.

METHODS

Prospective controlled observational study. Acid-base status was evaluated using the HH model, Fencl-Stewart (FS) approach and a validated strong ion model (VDM). The acid-base changes according to each model were classified and compared. Statistical correlations between pH, CO₂ , and various SIM variables were performed, as well as between the sum of effects (SOE) of the SIM and the individual variables comprising the SOE.

RESULTS

The HH model identified acid-base disorders in 31/44 cases of which 16/31 were mixed with metabolic acidosis and concurrent respiratory alkalosis the most common (10/31). Using the FS approach, metabolic changes were present 36/42 cases, with changes in free water (FW), chloride, and unmeasured anions (UA) being the most prevalent. Both FW and UA correlated well with pH; however, UA were most consistently abnormal in severe acidemia. Similarly to the HH, the VDM detected acid-base disturbances in 28/44 cases. Major contributors to the acid-base changes were hyponatremia, hypochloremia, and A_tot acidosis because of elevated globulins and increased UA.

CONCLUSIONS AND CLINICAL IMPORTANCE

Acid-base changes are common and complex in dogs with PE, and were easier to understand using a SIM paradigm. Increases in UA have not been documented in PE in dogs.

Microbiota in viral infection and disease in humans and farm animals

The influence of the microbiota on viral infection susceptibility and disease outcome is undisputable although varies among viruses. The purpose of understanding the interactions between microbiota, virus, and host is to identify practical, effective, and safe approaches that target microbiota for the prevention and treatment of viral diseases in humans and animals, as currently there are few effective and reliable antiviral therapies available. The initial step for achieving this goal is to gather clinical evidences, focusing on the viral pathogens-from human and animal studies-that have already been shown to interact with microbiota. The subsequent step is to identify mechanisms, through experimental evidences, to support the development of translational applications that target microbiota. In this chapter, we review evidences of virus infections altering microbiota and of microbiota enhancing or suppressing infectivity, altering host susceptibility to certain viral diseases, and influencing vaccine immunogenicity in humans and farm animals.

Comparison of oral, intravenous, and subcutaneous fluid therapy for resuscitation of calves with diarrhea

Neonatal diarrhea remains the primary cause of mortality in dairy calves around the world, and optimal treatment protocols are needed. The main goals of therapy are to restore hydration and electrolyte concentrations, correct strong ion (metabolic) acidemia, and provide nutritional support. Administration of oral electrolyte solutions (OES) has long been the primary method used to treat neonatal diarrhea in humans and calves because OES are capable of addressing each of the primary goals of therapy. In calves with moderate dehydration, we hypothesized that oral electrolytes would be as good as or better than small volumes of intravenous (IV) or subcutaneous (SC) fluids. Therefore, the main goal of this study was to compare the ability of a commercially available oral electrolyte solution (OES) administered alone or in combination with hypertonic saline with small volumes of IV or SC fluid therapy to resuscitate calves with diarrhea. Thirty-three Holstein calves from 5 to 14 d of age were utilized in this clinical trial. Diarrhea and dehydration were induced by adding sucrose to the milk replacer. In addition, hydrochlorothiazide and spironolactone were given orally and furosemide intramuscularly. Depression status, clinical hydration scores, fecal consistency, and body weight were recorded at regular intervals. Treatment began when calves had severe diarrhea and had a decrease in plasma volume of at least 10%. Calves were randomly assigned to 1 of 4 treatment groups of 8 to 9 calves per group: (1) OES; (2) OES with hypertonic saline (4 mL/kg, IV); (3) IV fluids (lactated Ringer's, 2 L); or (4) SC fluids (lactated Ringer's, 2 L). Treatments were given at 0 and 12 h. Changes in plasma volume, blood pH, electrolyte levels, and physical examination scores were determined before therapy and again at 1, 2, 4, 8, and 12 h after each treatment. All 4 treatments were ultimately successful in improving hydration as well as increasing blood pH; however, animals in both groups that received OES had much faster resuscitation than those in either the IV or SC fluid group. In conclusion, oral electrolyte products remain the gold standard for resuscitating diarrheic calves with moderate dehydration and acidemia and will likely perform better than small volumes of IV lactated Ringer's solution. Subcutaneous fluids by themselves are a poor treatment option and should be only be used as supportive therapy following the initial correction of hypovolemia and metabolic acidosis.

Prognostic value of preoperative plasma l-lactate concentrations in calves with acute abdominal emergencies

Acute abdominal emergencies in calves due to abomasal disorders, gastrointestinal ileus, or peritonitis are characterized by a rapid disease progression and usually require immediate surgical intervention. Those conditions are associated with a guarded prognosis, and the aim of the present study was to assess the prognostic relevance of preoperatively measured plasma l-lactate concentrations (l-LAC) in a large study population of calves with a broad spectrum of acute abdominal emergencies. For the purpose of this study, the medical records of 587 calves admitted to a veterinary teaching hospital over a 10-yr period were analyzed retrospectively. Plasma l-LAC was measured as part of a routinely performed biochemistry panel before initiation of surgical intervention. Hyper-l-lactatemia (plasma l-LAC >2.2 mmol/L) was evident in 75% of calves, and the overall survival rate until hospital discharge was 31%. Calves with a negative outcome were younger (median: 3.4 vs. 6 wk) and had higher plasma l-LAC (median: 4.96 vs. 3.09 mmol/L) than calves with a positive outcome. At the individual diagnosis level, l-LAC was associated with mortality in calves with a diagnosis of mesenteric torsion, right-sided dilated abomasum, small intestinal volvulus, or paralytic ileus, but not in calves suffering from peritonitis, malformations, abomasal volvulus, bloat, or small intestinal intussusceptions. Considering the whole study population, the area under the receiver operating characteristic (ROC) curve for plasma l-LAC was 0.66 [95% confidence interval (CI): 0.61-0.70]. A classification tree analysis indicated that l-LAC >8.84 mmol/L and age categories of <3 wk and <1 wk were independent predictors of mortality. The area under the ROC curve of this model was 0.75 (95% CI: 0.71-0.79) and the resulting sensitivity and specificity for the prediction of nonsurvival at the optimal probability cut-point of 0.62 were 67.7 and 76.6%, respectively. In conclusion, hyper-l-lactatemia is common in calves suffering from acute abdominal emergencies. Markedly increased plasma l-LAC is associated with an increased mortality risk, but it is not possible to reliably predict the outcome of affected calves based on a single, preoperative measurement. However, a clinically important finding of this study was that the ability to predict a negative outcome is improved when the age of the calf is considered in addition to plasma l-LAC.

Echocardiographic assessment of left ventricular systolic function in neonatal calves with naturally occurring sepsis or septic shock due to diarrhea

Sepsis is associated with clinically relevant cardiovascular changes. The objectives of this study were to evaluate the clinical value of echocardiography for monitoring left ventricular (LV) systolic function in septic calves. A prospective longitudinal study was performed using a convenience sample. Twenty septic calves and 10 healthy calves were enrolled in the study. Arterial blood pressure (BP) was measured and M-mode echocardiography performed to characterize LV systolic function; the latter included measurement of ejection fraction, EF; stroke volume, SVI and cardiac output indexed to body weight, CI; E-point of septal separation, EPSS; pre-ejection period, PEP; ejection time, LVET; ratio of PEP to LVET; velocity of circumferential shortening, Vcf, LV end-diastolic volume index (LVEDVI) and LV end-systolic volume index (LVESVI) on admission and 6, 24, 48 and 72 h later in septic calves and once in healthy calves. Admission data were compared using the Mann-Whitney U test and P < .05 was considered significant. Decreased preload and afterload were present in septic calves, as indicated by marked decreases in BP, LVEDVI, LVESVI, SVI, CI, EPSS when compared to healthy calves. Systolic function appeared adequate in septic calves, based on EF and FS compared to control calves. There was no difference in heart rate, LVET, PEP:LVET, or Vcf between septic and health calves. We conclude that circulatory dysfunction, rather than systolic dysfunction predominates in septic calves. Positive associations on admission between CI and LVEDVI, LVESVI, and SVI support this conclusion. Echocardiographic determination of LVEDVI and CI appears useful in directing treatment in septic calves.

Detection of endotoxin in plasma of hospitalized diarrheic calves

OBJECTIVES

To investigate whether lipopolysaccharide (LPS) is present in plasma of calves with naturally occurring diarrhea. The second objective was to determine whether plasma [LPS] correlates with clinical, hematological, biochemical, and acid-base variables, and whether [LPS] differs between surviving and nonsurviving diarrheic calves.

DESIGN

Prospective observational study (January 2012-May 2014).

SETTING

Veterinary teaching hospital.

ANIMALS

Thirty-four calves <28 days old admitted for diagnosis and treatment of diarrhea and 30 healthy control calves.

MEASUREMENTS AND MAIN RESULTS

Admission demographics, physical examination, blood gas, biochemistry analysis, and outcome data were recorded. Plasma concentration of LPS was determined using a bovine LPS ELISA assay. Plasma [LPS] was detected in both healthy and diarrheic calves. Plasma [LPS] was significantly higher in diarrheic than healthy calves (median: 0.99 ng/mL; Interquartile range (IQR): 0.068, vs 0.88 ng/mL; 0.065 ng/mL, respectively; P < 0.001). Plasma [LPS] was higher in nonsurviving (1.04 ng/mL; 0.07 ng/mL) than in surviving calves (0.98 ng/mL; 0.022 ng/mL; P < 0.001). Plasma [LPS] was higher in beef (1.07 ng/mL; 0.182 ng/mL) than in dairy diarrheic calves (0.99 ng/mL; 0.022 ng/mL; P < 0.001). In diarrheic calves, plasma [LPS] correlated with [l-lactate] (r² = 0.496; P = 0.002); hypoglycemia (r² = -0.453; P = 0.007); increased unmeasured strong ions (r² = 0.332; P = 0.050), [Mg²⁺ ] (r² = 0.475; P = 0.004), and [phosphate] (r² = 0.468; P = 0.005), and increased aspartate aminotransferase activity (r² = 0.348; P = 0.003).

CONCLUSIONS

This study highlights a potential role of LPS in the pathogenesis of metabolic derangements such as hyperlactatemia, hypoglycemia, and increased concentration of unmeasured strong anions in diarrheic calves. Further investigation evaluating the effect of LPS on l-lactate and glucose metabolism in diarrheic calves is warranted.

Plasma citrulline, arginine, nitric oxide, and blood ammonia levels in neonatal calves with acute diarrhea

Background

Plasma citrulline (CIT) concentration is considered to be a reliable marker of functional enterocyte mass, primarily in humans. However, information about CIT levels along with related metabolites, arginine (ARG), nitric oxide (NO), and ammonia in neonatal calves are lacking.

Objectives

To compare plasma CIT, ARG, NO, and whole blood ammonia concentrations in neonatal calves with acute diarrhea with those in healthy calves and to assess their possible relationships with diarrhea‐related criteria.

Animals

Seventy neonatal calves (60 with acute diarrhea and 10 healthy).

Methods

Observational case‐control study. Diarrheic calves were classified into subgroups on the basis of etiology, severity of diarrhea, degree of dehydration, and systemic inflammatory response syndrome (SIRS) status. Plasma CIT and ARG concentrations were measured by liquid chromatography/tandem mass spectrometry.

Results

Plasma CIT (median [range]: 67.5 [61.9‐75.4] vs 30.1 [15.0‐56.1] μmol/L) and ARG (170.7 [148.5‐219.5] vs 106.1 [54.4‐190.7] μmol/L) were lower and plasma NO (4.42 [3.29‐5.58] vs 6.78 [5.29‐8.92] μM) and blood ammonia concentrations (28.7 [26.1‐36.9] vs 59.8 [34.6‐99.5] μmol/L) were higher in the neonatal calves with diarrhea (P < .001). Plasma CIT (β = −0.29, P = .02), ARG (β = −0.33, P = .01), NO (β = 0.55, P < .001), and blood ammonia (β = 0.63, P <.001) were affected by SIRS status. Except for ammonia (0.52), the effects sizes for severity of diarrhea and degree of dehydration were small (ηp2 ≤ 0.45) for CIT, ARG, and NO.

Conclusions and Clinical Importance

The changes in these variables might have diagnostic, prognostic, and therapeutic value in diarrheic neonatal calves.

Characterization of intestinal Escherichia coli isolated from calves with diarrhea due to rotavirus and coronavirus

PURPOSE

To address more information about changes in commensal Escherichia coli during virus intestinal infection, we characterized 30 faecal E. coli isolates from calves (21 to 60 days old) with diarrhea due to rotavirus and coronavirus, which received, before diagnosis, tetracycline, gentamicin and enrofloxacin drugs.

METHODOLOGY

Clermont's phylogenetic classification; presence of genes for curli, cellulose, fimbriae (F4, F5, F6, F18, F41); and antimicrobial susceptibility were used to characterize the isolates. Disk diffusion technique and PCR were used as methodologies.

RESULTS

E. coli isolates from calves with diarrhea were phylogenetically classified as B1 (70%, 21/30), B2 (3.33%, 1/30), C (3.33%, 1/30), D (3.33%, 1/30), E (13.33%, 4/30) and unknown (6.7 %; 2/30), whereas E. coli isolates from the control group were classified only as B1 (83.3%, 25/30), E (10 %; 3/30) and unknown (6,7 %; 2/30). E. coli isolates from calves with diarrhea showed a much higher resistance profile with 16 (53.3%) multiresistant isolates. Only isolates (30%-9/30) from diarrheic calves were also positive for fimbriae, specifically 16.7% (5/30) for F5 and 13.3% (4/30) for F18.

CONCLUSION

To sum up, E. coli isolates from calves with diarrhea showed differences in relation to the control group, confirming changes in commensal E. coli during virus intestinal infection. It can be emphasized that some care should be taken to manage diarrheic calves: the pathological agent must be diagnosed prior to treatment; antibacterial treatment should be with antimicrobials with a different mechanism of action; and finally, treated animals should be maintained separately from others because they can carry micro-organisms with a resistant profile.

Hematological and biochemical parameters of dairy calves submitted to pegbovigrastim administration

This study was designed to evaluate the response of hematological and biochemical parameters submitted to pegbovigrastim administration and postchallenge with lipopolysaccharide (LPS). In experiment 1, 20 newborn Holstein calves were divided into 2 groups: the Imrestor (Elanco Saúde Animal, São Paulo, Brazil) group (IMR, n = 10), which received a 25 μg/kg of body weight (BW) subcutaneous administration of pegbovigrastim, and the control group (CTR, n = 10), which received a subcutaneous administration of 0.9% saline solution. Blood samples were collected on d 0, 10, 12, and 14 relative to birth to analyze the biochemical and hematological parameters. Moreover, growth measurements were taken on d 0, 7, 14, 21, and 60 relative to birth. The number of total leukocytes in the IMR group increased on d 12 and 14 in comparison to the CTR group, as well as the counts of segmented neutrophils, band cells, and monocytes. No differences were observed in the other hematological, biochemical, and growth parameters. In experiment 2, 20 Holstein calves from 30 to 60 d old were divided into 4 groups: group 1 (LPS, n = 5) received a 0.25 μg/kg of BW single intravenous dose of Escherichia coli LPS at d 0; group 2 (IMR, n = 5) received a 25 μg/kg of BW subcutaneous dose of pegbovigrastim at d 1; group 3 (IMR + LPS, n = 5) received a 0.25 μg/kg of BW intravenous LPS dose at d 0 and a 25 μg/kg of BW subcutaneous dose of pegbovigrastim at d 1; and group 4 (CTR, n = 5) received an intravenous dose of 0.9% sodium chloride at d 0 and a subcutaneous dose of 0.9% sodium chloride at d 1. For the analysis of biochemical and hematological parameters, blood samples were collected on d -1, 0, 1, 2, 3, 4, 8, 14, and 21 relative to LPS administration. An increase in the number of total leukocytes was observed in the IMR, IMR + LPS, and LPS groups, and the IMR group remained as the highest from d 2 to 21. The levels of paraoxonase 1 were higher in the IMR group compared with all the others. The administration of pegbovigrastim in the dairy calves increased the number of circulating leukocytes, especially neutrophils, with an increase in paraoxonase 1, without altering the metabolites for the hepatic function.

Electrocardiographic findings in 130 hospitalized neonatal calves with diarrhea and associated potassium balance disorders

Background

Hyperkalemia in neonatal diarrheic calves can potentially result in serious cardiac conduction abnormalities and arrhythmias.

Objectives

To document electrocardiographic (ECG) findings and the sequence of ECG changes that are associated with increasing plasma potassium concentrations (cK⁺) in a large population of neonatal diarrheic calves.

Animals

One hundred and thirty neonatal diarrheic calves (age ≤21 days).

Methods

Prospective observational study involving calves admitted to a veterinary teaching hospital.

Results

Hyperkalemic calves (cK⁺: 5.8‐10.2, blood pH: 6.55‐7.47) had significantly (P < .05) longer QRS durations as well as deeper S wave, higher T wave, and higher ST segment amplitudes in lead II than calves, which had both venous blood pH and cK⁺ within the reference range. The first ECG changes in response to an increase in cK⁺ were an increase in voltages of P, Ta, S, and T wave amplitudes. Segmented linear regression indicated that P wave amplitude decreased when cK⁺ >6.5 mmol/L, S wave amplitude voltage decreased when cK⁺ >7.4 mmol/L, QRS duration increased when cK⁺ >7.8 mmol/L, J point amplitude increased when cK⁺ >7.9 mmol/L, and ST segment angle increased when cK⁺ >9.1 mmol/L. P wave amplitude was characterized by a second common break point at cK⁺ = 8.2 mmol/L, above which value the amplitude was 0.

Conclusions and Clinical Importance

Hyperkalemia in neonatal diarrheic calves is associated with serious cardiac conduction abnormalities. In addition to increased S and T wave amplitude voltages, alterations of P and Ta wave amplitudes are early signs of hyperkalemia, which is consistent with the known sensitivity of atrial myocytes to increased cK⁺.

Hypoglycemia and failure of respiratory compensation are risk factors for mortality in diarrheic calves in Hokkaido, northern Japan

The aim of present study was to identify risk factors among laboratory findings for mortality in calves with diarrhea. A retrospective analysis was conducted utilizing medical records of 221 diarrheic calves (10.4 ± 3.7 days old) with no concurrent severe disorders that were treated with intravenous fluid therapy from the initial examination. Thirty-eight of the diarrheic calves (17.2%) died within 35 days from the initial examination. Multivariate logistic regression analysis indicated that hypoglycemia (OR 3.09; 95% CI 1.22–7.87; P=0.02) and failure of respiratory compensation (OR 2.63; 95% CI 1.05–6.62; P=0.04) were the major risk factors associated with a negative outcome in diarrheic calves. According to the Kaplan-Meyer analysis, diarrheic calves with hypoglycemia and/or failure of respiratory compensation had a significantly shorter survival than calves without these factors.

A prophylactic protocol to stimulate the immune response also controls infectious disease and, consequently, minimizes diarrhea in newborn heifers

The immunostimulatory and immunomodulatory properties of selenium (Se), an essential trace element for animals, has increase its use because may prevent/or reduce the occurrence of infectious diseases. Thus, the aim of this study was to verify whether Se and vitamins (A and E) applied via subcutaneous associated with secnidazole via oral exert positive effects in the antioxidant and immune systems, as well as whether prevent infections caused by protozoan and bacteria, and consequently, reduce the number of cases of diarrhea in heifers. Thirty-two newborn Holstein heifers were divided into two groups with sixteen animals each: the control group and the treated group that received sodium selenite (0.2 mg/kg) and vitamins A (35 mg/kg) and E (1 mg/kg) with one day of life, and a second application associated with secnidazole (400 mg/animal) on day 10 of life. Sample collection (blood and feces) were performed on days 1, 15, 30, 45 and 60 of life. Heifers from the treated group showed higher hematocrit values compared to the control group on day 60 of life, while total serum protein levels were higher on days 15 and 30. The ceruloplasmin (days 15, 30 and 60), IgG of heavy chain (days 15, 30, 45 and 60), IgG of light chain (days 45 and 60) and haptoglobin (days 15, 30, 45 and 60) were higher in the treated group compared to the control group. Serum levels of glucose decreased in treated animals on day 60 of life, while serum levels of albumin, triglycerides, urea, cholesterol, thiobarbituric acid reactive substances, reactive oxygen species and glutathione S-transferase activity did not differ between groups. Secnidazole was able to prevent infections caused by Giardia duodenalis in the first few days of life, but no difference was observed between groups. Moreover, there was no difference on total bacteria count and the incidence of diarrhea between groups. No difference on weight gain was observed on day 60 of life, but on day 210 of life treated animals had higher weight gain compared to the control group. Based on these evidences, we concluded that the injectable application of Se and vitamins (A and E) associated to secnidazole can improve the immunological system, and consequently, favor animal's performance.

Diagnosis and Treatment of Infectious Enteritis in Neonatal and Juvenile Ruminants

Common causes of infectious enteritis in neonate and juvenile ruminants include viral, bacterial, and protozoal pathogens. The most common presenting sign in ruminants with infectious enteritis is diarrhea. Diagnosis of the cause of enteritis has important zoonotic and herd health implications. Severity of clinical signs with similar pathogens may differ between calves and small ruminants. Treatment of enteritis involves supportive care to correct fluid and electrolyte imbalances, provision of nutritional support for neonates, prevention and treatment of endotoxemia or sepsis, and pathogen-specific treatments when relevant and available.