Objective:To compare measured ECG intervals and amplitudes obtained using electrocardiographs adapted for veterinary or human use and to develop ECG reference intervals for endurance-trained dogs. Methods:Standard limb lead ECG recordings were obtained simultaneously in February and early March of 2021 using 2 digital electrocardiographs and a convenience sample of 121 endurance-trained sled adult dogs. Visually verified computer-based ECG measurements for the 2 electrocardiographs were compared using the Wilcoxon signed-rank test, Deming regression, and Bland-Altman plots. We assigned acceptable median values for differences (effect sizes) of < 10 milliseconds for P-wave duration, PQ interval, QRS duration, JT interval, and QT interval and < 10% for P-, Q-, R-, S-, and T-wave amplitudes. Results:Statistically significant differences between the 2 electrocardiographs existed for the majority (7 of 9) of global ECG indices and the majority (10 of 15) of lead I-, II-, and III-wave amplitudes. Clinically important differences based on assigned effect sizes were identified for lead II and III Q- and R-wave amplitudes, which the veterinary electrocardiograph measured 11% to 23% higher. The veterinary electrocardiograph identified a higher proportion of dogs that may have left or right ventricular enlargement. Reference intervals developed for 7 of 9 global ECG indices were narrower for the veterinary electrocardiograph. Conclusions:The low-pass filter on the veterinary electrocardiograph attenuates higher frequencies on the canine ECG to a lower extent than the human electrocardiograph. Clinical Relevance:Reference intervals for dog ECGs depend on the digital electrocardiograph, its high-frequency filtering characteristics, and its computer-based analysis program.

BACKGROUND:Sepsis has been defined in humans as the concurrent proven or suspected presence of microbial infection and the systemic inflammatory response syndrome (SIRS). Sepsis is the leading cause of morbidity and mortality in neonatal foals. The clinical utility of using SIRS or its individual components to predict infection and mortality in critically ill foals is currently unknown. OBJECTIVES:Assess the ability of history and signalment, clinical findings, laboratory results, and SIRS-related indices to predict infection and mortality in critically ill foals. ANIMALS:Retrospective, multi-center, cross-sectional study using a convenience sample of 1068 critically ill foals < 3 days of age admitted to 16 veterinary referral hospitals in 4 countries. METHODS:Data were retrieved from medical records. Infection was defined as the presence of bacteremia (positive blood culture) or clinical identification of an infected focus on admission. Univariate non-parametric and categorical methods, multivariate logistic regression, and classification tree methods were used for statistical analysis. RESULTS:Foal age at admission and presence of toxic neutrophils were independent predictors of infection, whereas SIRS-related indices were not predictive of infection. In-hospital mortality was 24%. Independent predictors for mortality were hypokinetic pulses, cold extremities, presence of seizures, blood L-lactate concentration > 6.0 mmol/L, and increased serum potassium and total bilirubin concentrations. CONCLUSIONS AND CLINICAL IMPORTANCE:The presence of infection in critically ill newborn foals was not predicted by SIRS indices. Cardiovascular dysfunction was strongly associated with mortality, suggesting that maintaining adequate perfusion and pulse pressure should be important treatment goals.

The objective of this case-control study was to assess gut permeability, measured through Cr-EDTA recovery, in healthy and diarrheic neonatal calves. The study was conducted at a commercial calf-rearing facility, where fecal consistency was monitored twice daily. Calves were categorized as diarrheic if they had runny or watery feces, whereas those with normal fecal consistency, neutrophil count, and physical exam findings were considered healthy controls. Gut permeability assessment (Cr-EDTA: 0.1 g/kg BW administered orally 2 h after milk feeding) and blood bacterial culture were performed 24 h after onset of diarrhea. Plasma Cr concentration was determined using inductively coupled plasma mass spectrometry. Wilcoxon signed-rank test and Kruskal-Wallis tests, followed by Dunn's post hoc test, were used to compare Cr concentrations between groups. The study included 12 healthy calves and 11 diarrheic calves, with 5 diarrheic calves having bacteremia. Diarrheic calves had greater median (interquartile range) plasma Cr concentrations than healthy calves at 2 h (1.76 [0.92–2.34] mg/L vs. 0.59 [0.48–1.19] mg/L) and 4 h (2.07 [1.57–2.51] mg/L vs. 0.92 [0.77–1.66] mg/L) postadministration, respectively. Both bacteremic and nonbacteremic calves with diarrhea had greater plasma Cr concentrations at 2 h compared with healthy calves (bacteremic: 1.96 [1.76–2.03] mg/L; nonbacteremic: 1.42 [0.78–2.34] mg/L), but there was no difference between bacteremic and nonbacteremic calves. At 4 h postadministration, both bacteremic (2.00 [1.67–2.07] mg/L) and nonbacteremic (2.45 [1.57–3.66] mg/L) diarrheic calves had greater plasma Cr concentrations than healthy calves, with no difference observed between bacteremic and nonbacteremic groups. This study suggests an association between diarrhea and increased gut permeability in neonatal calves. Further studies are required to compare gut permeability in a larger cohort of bacteremic and nonbacteremic diarrheic neonatal calves.

BACKGROUND:Johne's disease, also known as paratuberculosis, is a chronic granulomatous enteritis disease that affects ruminants worldwide. OBJECTIVE:The objective of this study was to assess the effectiveness of the immunomagnetic bead separation-immunosensor (IMB-IS) detection method compared to Nested-PCR for identifying Mycobacterium avium subspecies paratuberculosis (MAP) infection in cattle feces samples. METHODS:Ninety rectal fecal samples were collected from selected cattle, comprising 59 serum-positive and 31 serum-negative cases based on serum ELISA. Following DNA extraction, nested-PCR was conducted using the IS900 primer sequence targeting the MAP-specific gene. Immunomagnetic bead (IMB) nanoparticles were synthesized by purifying hyperimmune donkey IgG through affinity chromatography and then conjugating it to Fe nanoparticles. Rhodamine-B hydrazone immunosensor (IS) was synthesized and conjugated to hyperimmune rabbit IgG. The synthesized IMB and IS were used to identify MAP in cattle fecal samples. RESULTS:The results of this study revealed that of the 90 stool samples tested using the nested-PCR method, 62 samples (68.88%) were positive, while 28 samples (31.12%) were negative. In the IMB-IS test based on optical density (OD), 64 samples were positive (71.1%), while 26 samples were negative (28.8%). This test exhibited a sensitivity of 100%, specificity of 92.85%, and an overall test accuracy of 97.77%. CONCLUSION:Given the considerations of cost, time, positive and negative predictive values, and acceptable accuracy of the IMB-IS test, it is recommended for evaluation in screening and epidemiological studies.

IntroductionAfter the neonatal period Eimeriosis is one of the most common causes of large intestinal diarrhea in calves. In contrast to neonatal calves with diarrhea, there are very few reports about the clinicopathological alterations in affected animals, which are mainly based on experimental data. The aim of the present study was therefore to characterize acid–base and related clinicopathologic alterations in calves with Eimeria-associated diarrhea and to identify variables associated with in-hospital mortality.MethodsRetrospective analysis of clinical and clinicopathologic findings extracted from medical records of 118 calves aged 1 to 5 months admitted to a veterinary teaching hospital.ResultsSeverely affected calves were profoundly hyponatremic and hypochloremic, with a strong correlation between plasma sodium and chloride concentrations (Spearman’s rs = 0.90). Acidemia was found in 57.6% of calves and was associated with hyperphosphatemia, hyper-L-lactatemia, and the presence of unidentified strong ions. Forty-seven calves (39.8%) did not survive to hospital discharge. Classification tree analysis indicated that hospital mortality was associated with plasma ionized calcium concentrations <1.05 mmol/L, initial leukocyte counts >16 × 109 cells/L, and a poor or cachectic body condition. The resulting sensitivity and specificity for predicting non-survival of this model was 59.6 and 90.1%, respectively. In addition to plasma ionized calcium [Odds ratio (OR) = 0.011] and leukocyte concentrations (OR = 1.08), recumbency (OR = 6.1), albumin (OR = 0.90), and decreased strong ion difference (OR = 0.91) were associated with mortality in a second modeling approach (sensitivity 78.7%, specificity 71.8%).ConclusionCalves with Eimeria-associated diarrhea can develop profound clinicopathologic derangements. The identified prognostic factors suggest that advanced disease severity, indicated by an inability to stand and reduced body condition, is associated with a lower chance of survival.

The objective of this study was to determine whether a novel footbath solution containing stannous fluoride (SnF2) was superior to 5% copper sulfate solution for the treatment and prevention of digital dermatitis (DD) in dairy cattle. Study 1 was conducted over 4 wk in Missouri and involved 34 lactating Holstein-Friesian cows with hind feet DD lesions. Cows in group SF walked through a footbath containing a proprietary formulation of SnF2 once weekly, whereas cows in group CS walked through a 5% CuSO4 footbath once daily for 5 d each week. Study 2 was conducted over 8 wk in California and involved 40 lactating Holstein-Friesian cows with hind feet DD lesions. Cows in group SF walked through a SnF2 footbath for 3 consecutive days and then once a week for the following 7 wk. Cows in group CS walked through a 5% CuSO4 footbath 3 times each week for 8 wk. Data collection included lesion type, lesion area, locomotion score, and pain score. Digital dermatitis was actively transmitted in study 1, and lesion area and locomotion scores were lower in group SF than group CS. In contrast, DD was not actively transmitted in study 2, and lesion area and locomotion scores were similar in groups SF and CS. Stannous fluoride delayed the development of active DD lesions in study 1 compared with copper sulfate, with a lower relative risk (0.57) of a hind foot developing an active DD lesion over 28 d. However, SnF2 decreased the rate that active DD lesions transitioned to M3, M4, or M0 lesions compared with 5% copper sulfate in both studies, with the relative risk of a hind foot with an active DD lesion transitioning to M3, M4, or M0 in group SF being slightly lower in study 1 (0.83) and study 2 (0.90) than in group CS. Our findings demonstrated that walking cows through a stannous fluoride footbath once per week in a herd undergoing active transmission of infection was more effective in preventing active DD lesions, but less effective in treating active DD lesions, than walking cows through a copper sulfate footbath 4 times per week. The novel SnF2 footbath solution shows promise for controlling DD in dairy herds that want an alternative footbath solution to CuSO4 and are interested in limiting the environmental accumulation of copper.

Abstract Background Surgical abdominal emergencies in calves are associated with a guarded prognosis and have the potential for complex metabolic derangements including acid‐base imbalances. Objectives To perform a comprehensive analysis of acid‐base status and to assess the prognostic relevance of preoperative clinicopathologic variables in calves undergoing abdominal surgery. Animals Hospital‐based study samples of 535 (dataset 1; DS1) and 83 calves (dataset 2; DS2). Methods Retrospective (DS1) and prospective (DS2) case series. Results In DS1, acidemia (pH <7.33) was present in 49.9%, whereas alkalemia (pH >7.37) was present in 30.7% of calves. Plasma L‐lactate, chloride, and serum inorganic phosphorus concentration accounted for 51.9%, 11.6% and 9.4% of the variation of venous blood pH, respectively. Classification tree analysis indicated that a negative outcome (death or euthanasia during hospitalization) was associated with venous pO2 ≤33.6 mm Hg, anion gap >18.3 and >22.9 mEq/L, serum albumin concentration ≤36.5 and ≤29.4 g/L, serum urea concentration >4.4 mmol/L, and plasma ionized calcium concentration ≤1.26 mmol/L. The area under the receiver operating characteristic curve of this model was 0.85 (95% CI: 0.82‐0.89, P < .001) and the resulting sensitivity and specificity for the prediction of nonsurvival at the optimal probability cut‐point of 0.5 was 89.8% and 65.7%, respectively. In DS2 the model had a similar sensitivity and specificity of 90.5% and 70%, respectively. Conclusions and Clinical Importance Clinicopathologic imbalances and associated changes of acid‐base status are common in calves with surgical abdominal emergencies and have clinical utility for the prediction of a negative postoperative outcome.

AimsThe major objective of this study was to investigate the efficacy of heat‐treating colostrum on the subsequent growth characteristics (weight gain, body size, dry matter intake and feed efficiency rate) and health of Holstein calves.MethodsA total of 1200 neonatal Holstein calves on one commercial dairy farm were enrolled. The calves were divided into heat‐treated (60°C for 90 min) and unheated (raw) colostrum groups. Calf serum IgG and total protein concentrations were measured before and after colostrum consumption. Health characteristics and disease prevalence were recorded during the suckling period.ResultsConsumption of heat‐treated colostrum led to increased serum IgG (P < 0.0001) and total protein (P < 0.0001) concentrations, increased apparent efficacy of IgG absorption (P < 0.0001) and increased general health condition, weight gain (P < 0.0001) and clinical performance.Conclusions and clinical relevanceHeat‐treatment of colostrum is an effective method to improve health and increase growth characteristics (weight gain, body size, dry matter intake and feed efficiency rate) of neonatal dairy calves, most likely by decreasing microbial load and facilitating IgG absorption.

BACKGROUND:Data on the factors affecting blood ionized calcium concentration (ciCa2+ ) and diagnostic performance of serum total calcium concentration (ctCa) measurements to detect abnormal blood iCa2+ status are lacking in sick adult cattle. OBJECTIVE:Assess the association of ciCa2+ with venous blood pH, plasma concentrations of chloride (cCl), sodium (cNa), and potassium (cK), and ctCa, and total protein, albumin, and globulin concentrations in sick adult cattle. ANIMALS:Two-hundred and sixty-five adult cattle (≥1-year-old) with different diseases. METHODS:Prospective study. Whole blood pH, ciCa2+ , cNa, cK, and cCl were measured using a blood gas and electrolyte analyzer, whereas ctCa, and total protein, and albumin concentrations were determined using an autoanalyzer. The relationship between ciCa2+ and venous blood pH, plasma cCl, cNa, cK, and ctCa, and total protein, albumin, and globulin concentrations was investigated. Sensitivity and specificity were calculated for ctCa for diagnosis of abnormal ciCa2+ . RESULTS:Sensitivity of ctCa measurements to detect abnormal ciCa2+ was 66.0% whereas specificity of ctCa measurements was 72.3%. Serum total calcium concentration measurements accounted for 42% of adjusted blood ionized calcium (iCa2+ 7.40 ) concentration variance. Plasma cCl, and cK had explanatory power of ciCa2+ 7.40 , accounting for an additional 21% and 9% of the variance, respectively. CONCLUSIONS AND CLINICAL IMPORTANCE:Serum tCa measurements failed to accurately predict blood iCa2+ status in ill adult cattle. Serum tCa concentrations and plasma cCl were the strongest predictors of ciCa2+ in sick adult cattle.

BACKGROUND:Canine C-reactive protein (cCRP) is an acute-phase protein that increases dramatically with inflammation and has potential utility in monitoring disease progression and response to treatment. Rapid, automated point-of-care test (POCT) formats could enhance the clinical utility of cCRP measurement.OBJECTIVES:We aimed to evaluate the VetChroma canine-specific POCT assay for the quantitative measurement of cCRP in canine serum or plasma.METHODS:Serum and plasma from discarded canine diagnostic samples were used. Evaluation included intra- and inter-assay coefficients of variation and observed total error (TEobs ), linearity and spike recovery, the effect of interfering substances and sample matrices, and a method comparison study.RESULTS:Intra-assay variation ranged from 2.5%-6.1%, and inter-assay variation ranged from 2.1%-5.4%. The TEobs ranged from 15.1%-19.7%. The assay was linear over the manufacturer's analytical range with no evidence of constant or proportional bias. Recovery of purified cCRP from canine serum ranged from 116.2% to 138.4%. Hemolysis, icterus, and turbidity did not interfere with the assay. The comparison of paired plasma and serum samples revealed constant and proportional bias. Comparison of the VetChroma cCRP assay to a commercial cCRP ELISA revealed significantly different results.CONCLUSIONS:The VetChroma cCRP assay has acceptable test performance to measure serum cCRP concentration. The POCT protocol and test kit are valid for clinical use, although results obtained using other cCRP assays or plasma may not be directly compared.

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.

The aim of this study was to develop and evaluate a method for detecting Mycobacterium avium ssp. paratuberculosis (MAP) bacteria in bovine fecal, milk, and colostrum samples using immunomagnetic beads (IMB) and a rhodamine hydrazone immunosensor. Immunomagnetic beads were prepared by using purified antibodies from hyperimmunized sera that were coupled to Fe nanoparticles with diethylene triamine pentaacetic acid (DTPA) or ethyl (dimethyl aminopropyl) carbodiimide (EDC)-N-hydroxy succinimide (NHS) as linkers. Rhodamine hydrazone particles were synthesized and coupled to IgY anti-MAP antibodies using DTPA or EDC-NHS linkers. Separation efficiency of the IMB was tested on bovine fecal, milk, and colostrum samples experimentally contaminated with MAP. The studied methods were evaluated on their ability to detect MAP and separate bacteria in complex mediums. The ELISA results indicated 95% efficacy in antibody coupling to IMB, with the DTPA-IMB method being more efficient than the EDC-NHS-IMB method. By using the DTPA-IMB method, MAP bacteria were successfully recovered from fecal, milk, and colostrum samples. The DTPA-IMB method used in combination with the rhodamine hydrazone immunosensor had a limit of detection equal to 30 and 30,000 MAP cells/mL using chromogenic and fluorescent properties, respectively. Combining the DTPA-IMB separation method with the rhodamine hydrazone immunosensor provides a fast, sensitive, and cost-beneficial method for detecting MAP in bovine feces, milk, and colostrum.

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.

BACKGROUND:Blood gas chemistry analyzers typically produce results faster and use smaller sample volumes than reference chemistry analyzers. However, results may not be comparable between blood gas chemistry analyzers and reference chemistry analyzers or between different models of blood gas chemistry analyzers. This could suggest the use of separate reference intervals and, thus, has implications when making clinical decisions.OBJECTIVE:We aimed to perform method comparison studies to evaluate selected canine serum biochemical values obtained using the Nova Stat Profile Prime Plus VET (Prime Plus VET), Stat Profile Nova pHOx Ultra (Ultra), and Beckman Coulter AU680 (Beckman) analyzers. We hypothesized that the three analyzers would be identical within inherent imprecision.METHODS:Jugular venous blood samples were collected from 103 endurance-trained sled dogs, and serum was harvested and stored for analysis. Results for serum chloride, potassium, sodium, creatinine, and urea nitrogen concentrations obtained from the Prime Plus VET and Ultra analyzers were compared with results from the Beckman analyzer, which was considered to be a reference method. Results for serum chloride, potassium, sodium, creatinine, urea nitrogen, and L-lactate concentrations obtained from the Prime Plus VET and Ultra analyzers were compared. Passing-Bablok regression and Bland-Altman plots were used for method comparison.RESULTS:Significant (P < 0.05) constant or proportional bias was found for many analytes for all three method comparison studies.CONCLUSIONS:Due to the presence of statistically significant differences between all three analyzers that may be clinically relevant, it is recommended that reference intervals be created for new blood gas analyzers, even when similar methodologies are used.