Anne-Marie Belanger

Comparison of Thoracic Auscultation, Clinical Score, and Ultrasonography as Indicators of Bovine Respiratory Disease in Preweaned Dairy Calves

Background The diagnostic tools for bovine respiratory disease diagnosis include clinical inspection, thoracic auscultation, and ultrasonography. Hypothesis Thoracic auscultation and clinical examination have limitations in the detection of lung consolidation in dairy calves. Animals Prospective cohort of 106 preweaned calves from 13 different dairy herds (10 with a history of active bovine respiratory disease (BRD) in calves and 3 without suspected BRD problems). Methods Each preweaned calf was clinically inspected using the Wisconsin calf respiratory scoring chart (CRSC) and treatment history was noted. Systematic thoracic auscultation and ultrasonography then were performed, the latter focusing on lung consolidation. Mortality was recorded over a 30‐day period. Results A total of 56 of 106 calves had ultrasonographic evidence of lung consolidation. The sensitivity of thoracic auscultation to detect consolidation was 5.9% (range, 0–16.7%). Only 41.1% (23/33) of calves with consolidated lungs had been treated previously by the producers. When adding CRSC and previous BRD treatment by the producer, sensitivity of detection increased to 71.4% (40/56). The area under the receiver operating characteristics curve was 0.809 (95% CI, 0.721–0.879) for the number of areas within the lungs with consolidation and 0.743 (95% CI, 0.648–0.823) for the maximal depth of consolidation as predictors of death within 1 month after examination. These were not significantly different (P = .06). Conclusions and Clinical Importance This study shows that thoracic auscultation is of limited value in diagnosing lung consolidation in calves. Ultrasonographic assessment of the thorax could be a useful tool to assess BRD detection efficiency on dairy farms.

Comparison of 2-step laparoscopy-guided abomasopexy versus omentopexy via right flank laparotomy for the treatment of dairy cows with left displacement of the abomasum in on-farm settings.

OBJECTIVE To compare characteristics and results of 2-step laparoscopy-guided abomasopexy versus omentopexy via laparotomy in the right paralumbar fossa for the treatment of dairy cows with a left displaced abomasum (LDA). DESIGN Prospective clinical trial. 253 dairy cows with an LDA. PROCEDURES All cows that were treated with omentopexy (n = 101) or 2-step laparoscopy-guided abomasopexy (152) from July 2005 through December 2006 were included. Presurgical, perisurgical, and postsurgical information was recorded by attending veterinarians. Producers were interviewed by telephone 7 and 60 days after surgery regarding the response of cows to surgery. Characteristics of and responses to the 2 surgical techniques were compared. RESULTS At 7 days after surgery, the 2 groups of cows were not significantly different with respect to appetite, comfort, and milk yield; at 60 days after surgery, groups were similar with respect to milk yield, cull rates, and risk of relapse of LDA. Antimicrobial treatment in response to postsurgical pyrexia was necessary in only 20.4% (31/152) of cows that were treated with 2-step laparoscopy-guided abomasopexy. Mean duration (preparation and surgery) of 2-step laparoscopy-guided abomasopexy was significantly less than that of omentopexy (36 vs 74 minutes, respectively). CONCLUSIONS AND CLINICAL RELEVANCE Results of 2-step laparoscopy-guided abomasopexy and omentopexy via laparotomy in the right paralumbar fossa were not significantly different. Compared with omentopexy, laparoscopy-guided abomasopexy was performed more quickly and required postsurgical administration of antimicrobials less frequently. Although these factors may be of economic consequence to veterinarians and producers, other aspects must also be considered when choosing between techniques.

Preoperative cow-side lactatemia measurement predicts negative outcome in Holstein dairy cattle with right abomasal disorders

The objectives of the current study were (1) to determine the gain in prognostic accuracy of preoperative l-lactate concentration (LAC) measured on farm on cows with right displaced abomasum (RDA) or abomasal volvulus (AV) for predicting negative outcome; and (2) to suggest clinically relevant thresholds for such use. A cohort of 102 cows with on-farm surgical diagnostic of RDA or AV was obtained from June 2009 through December 2011. Blood was drawn from coccygeal vessels before surgery and plasma LAC was immediately measured by using a portable clinical analyzer. Dairy producers were interviewed by phone 30 d following surgery and the outcome was determined: a positive outcome if the owner was satisfied of the overall evolution 30 d postoperatively, and a negative outcome if the cow was culled, died, or if the owner reported being unsatisfied 30 d postoperatively. The area under the curve of the receiver operating characteristic curve for LAC was 0.92 and was significantly greater than the area under the curve of the receiver operating characteristic curve of heart rate (HR; 0.77), indicating that LAC, in general, performed better than HR to predict a negative outcome. Furthermore, the ability to predict a negative outcome was significantly improved when LAC measurement was considered in addition to the already available HR data (area under the curve: 0.93 and 95% confidence interval: 0.87, 0.99). Important inflection points of the misclassification cost term function were noted at thresholds of 2 and 6 mmol/L, suggesting the potential utility of these cut-points. The 2 and 6 mmol/L thresholds had a sensitivity, specificity, positive predictive value, and negative predictive value for predicting a negative outcome of 76.2, 82.7, 53.3, and 93.1%, and of 28.6, 97.5, 75, and 84%, respectively. In terms of clinical interpretation, LAC ≤2 mmol/L appeared to be a good indicator of positive outcome and could be used to support a surgical treatment decision. The treatment decision for cows with LAC between 2 and 6 mmol/L, however, would depend on the economic context and the owners attitude to risk in regard to potential return on its investment. Finally, performing a surgical correction on commercial cows with RDA or AV and a LAC ≥6 mmol/L appeared to be unjustified and these animals should be culled based on their high probability of negative outcome.

Respiratory pathogens in Québec dairy calves and their relationship with clinical status, lung consolidation, and average daily gain.

Background Bovine respiratory disease (BRD) is 1 of the 2 most important causes of morbidity and mortality in dairy calves. Surprisingly, field data are scant concerning the prevalence of respiratory pathogens involved in BRD in preweaned dairy calves, especially in small herds. Objectives To identify the main respiratory pathogens isolated from calves in Québec dairy herds with a high incidence of BRD, and to determine if there is an association between the presence of these pathogens and clinical signs of pneumonia, lung consolidation, or average daily gain. Animals Cross‐sectional study using a convenience sample of 95 preweaned dairy calves from 11 dairy herds. Methods At enrollment, calves were weighed, clinically examined, swabbed (nasal and nasopharyngeal), and lung ultrasonography was performed. One month later, all calves were reweighed. Results Twenty‐two calves had clinical BRD and 49 had ultrasonographic evidence of lung consolidation. Pasteurella multocida, Mannheimia haemolytica, and Histophilus somni were isolated in 54, 17, and 12 calves, respectively. Mycoplasma bovis was identified by PCR testing or culture in 19 calves, and 78 calves were found to be positive for Mycoplasma spp. Bovine coronavirus was detected in 38 calves and bovine respiratory syncytial virus in 1. Only the presence of M. bovis was associated with higher odds of clinical signs, lung consolidation, and lower average daily gain. Conclusions and Clinical Importance Results suggested that nasopharyngeal carriage of M. bovis was detrimental to health and growth of dairy calves in small herds with a high incidence of BRD.

Duodenal obstruction caused by duodenal sigmoid flexure volvulus in dairy cattle: 29 cases (2006-2010).

OBJECTIVE To characterize duodenal sigmoid flexure volvulus (DSFV) and determine the prognosis for affected cattle undergoing surgery. DESIGN Retrospective case series. ANIMALS 29 dairy cattle. PROCEDURES The medical records were analyzed for history, signalment, clinical signs, medical management, surgical findings, and outcome. RESULTS 29 cattle were determined to have DSFV between December 2006 and August 2010. Twenty cattle had had an omentopexy or pyloropexy performed 1 day to 2 years before initial evaluation. Cattle were afebrile, tachycardic, and moderately dehydrated, with a small zone of percussion with a ping at the 10th to 12th right intercostal spaces and associated succussion. Biochemical changes were a severe hypokalemic (mean ± SD, 2.9 ± 0.5 mmol/L; median, 3.1 mmol/L; range, 2.08 to 3.92 mmol/L), hypochloremic (mean, 69.7 ± 11.1 mmol/L; median, 71.7 mmol/L; range, 49.1 to 94.1 mmol/L) metabolic alkalosis (mean total CO(2), 44.5 ± 7.4 mmol/L; median, 45.3 mmol/L; range, 31.5 to 59.6 mmol/L) and hyperbilirubinemia (mean, 32.4 ± 29.0 μmol/L; median, 20.5 μmol/L; range, 7.8 to 107 μmol/L). Surgical findings for DSFV included an empty descending duodenum adjacent to a dorsally displaced and dilated cranial segment of the duodenum, distended abomasum and gallbladder, and a tight volvulus at the base of the duodenal sigmoid flexure. Manual reduction was considered successful if the descending duodenum filled after cranial duodenal massage. Twenty-two patients were successfully treated; the remaining 7 died or were euthanized within 4 days after surgery. CONCLUSIONS AND CLINICAL RELEVANCE A condition clinically resembling abomasal volvulus but affecting the duodenal sigmoid flexure has been recognized in dairy cattle. When a focal, dorsal right-sided ping and succussion are present combined with severe hypokalemic, hypochloremic metabolic alkalosis and high bilirubin concentration, DSFV should be suspected, especially when there is a history of prior abomasal fixation. After surgical correction, the prognosis is fair to good.

Short communication: Evaluation of the accuracy of an electronic on-farm test to quantify blood β-hydroxybutyrate concentration in dairy goats

The objective of this cross-sectional study was to validate the accuracy of a hand-held electronic on-farm test (Precision Xtra) for quantifying the blood β-hydroxybutyrate (BHBA) concentration in dairy goats. A total of 114 dairy goats from 3 commercial herds were sampled once for blood in the jugular vein between 1mo before and 2mo after parturition. Blood samples were centrifuged to harvest serum and sera were sent to the Animal Health Laboratory of the Université de Montréal for quantification of BHBA concentration (gold standard). Laboratory BHBA values were between 0.1 and 3.7mmol/L. Precision Xtra values were compared with gold standard values; Pearson correlation coefficient was 0.98 and coefficient of determination was 0.95. Overall, these results suggested that Precision Xtra provides excellent accuracy for measuring blood BHBA concentration in dairy goats compared with the gold standard test.

Ultrasonographic appearance of lymphomatous infiltration of the abomasum in cows with lymphoma

CASE DESCRIPTION 4 adult Holstein dairy cows were examined for anorexia and decreased milk production. CLINICAL FINDINGS Clinical signs included abdominal distension, normal to decreased ruminal motility, and decreased fecal output. Hypochloremia and high BUN concentration were also noted on serum biochemical analysis. Transabdominal ultrasonography revealed abnormal thickening of the abomasum with pyloric thickening and loss of the typical layered appearance of the pyloric wall. Results of cytologic examination of fine-needle aspirates of the abnormal portion of the abomasum were compatible with a diagnosis of lymphoma in 3 cows. OUTCOME The diagnosis of lymphoma involving the abomasum was confirmed by exploratory laparotomy, necropsy, or slaughterhouse reports. Two cows were euthanatized, 1 died 5 days after the diagnosis, and 1 was sent to the slaughterhouse, but the carcass was discarded because of generalized lymphoma. CLINICAL RELEVANCE Transabdominal ultrasonography is a noninvasive portable test that can be useful for the diagnosis of lymphomatous infiltration of the pyloric portion of the abomasum, which may result in obstruction. This can be especially useful to avoid unnecessary treatments when no typical signs of enzootic lymphoma are present. Percutaneous fine-needle aspiration of the abnormally thickened abomasal wall should be performed. These procedures can enable diagnosis of this neoplasm, which has a relatively poor prognosis, thus avoiding the unnecessary costs incurred by exploratory laparotomy.

Definition of prepartum hyperketonemia in dairy goats

A prospective cohort study was conducted on 1,081 dairy goats from 10 commercial herds in Québec (Canada) to define prepartum hyperketonemia based on optimal blood β-hydroxybutyrate acid threshold values for the early prediction of pregnancy toxemia (PT) and mortality in late-gestation dairy goats. All pregnant goats had blood sampled weekly during the last 5wk of pregnancy. The blood was analyzed directly on the farm for β-hydroxybutyrate acid quantification using a Precision Xtra meter (Abbott Diabetes Care, Saint-Laurent, QC, Canada). Body condition scores on the lumbar region and sternum were noted. Each goat was classified as being at low (n=973) or high risk (n=108) of having PT by producers based on a standardized definition. The optimal threshold for predicting a PT diagnosis or mortality for each week before kidding was determined based on the highest sum of sensitivity and specificity. The association between hyperketonemia and subsequent PT was tested using a multivariable logistic regression model considering hyperketonemia at wk 4 prepartum, litter size, and body condition score at wk 4 prepartum as covariates, and herd and parturition cohort as random effects. The association between mortality and hyperketonemia was also tested using a logistic regression model accounting for the presence or absence of treatment during the last month of pregnancy. The hyperketonemia definition based on PT varied between ≥0.4 and ≥0.9mmol/L during the last 5wk prepartum. Goats affected by hyperketonemia at wk 4 prepartum and with a large litter size (≥3 fetuses) had 2.1 and 40.5 times the odds, respectively, of subsequent PT than other goats. Hyperketonemia definitions based on mortality varied between ≥0.6 and ≥1.4mmol/L during the last 4wk prepartum, and was ≥1.7mmol/L during the first week postpartum. Goats affected by hyperketonemia and treated by producers had 3.4 and 11.8 times the odds, respectively, of subsequent mortality than did other goats. These results showed that prepartum hyperketonemia could be defined in dairy goats using subsequent risks of PT or mortality during the last month of pregnancy.

Echocardiographic findings of tricuspid blood cyst mimicking bacterial endocarditis in a dairy cow.

The most common endocardial disease in cattle is bacterial endocarditis. The diagnosis of the disease in living animals is mainly based on clinical findings and echocardiographic detection of an irregularly thickened valve. Despite its presumed good sensitivity, little is known on the specificity of transthoracic echocardiography with regards to endocarditis. This case report describes the echocardiographic findings in a dairy cow diagnosed with a chronic inflammatory process, liver and splenic abscesses and tricuspid valve blood cysts that can be mistaken for bacterial endocarditis, thus emphasizing the need to improve antemortem diagnostic tools for endocarditis in cattle.

Inter-rater agreement and reliability of thoracic ultrasonographic findings in feedlot calves, with or without naturally occurring bronchopneumonia

Background Thoracic ultrasonography (TUS) can be used to assess the extent and severity of lung lesions associated with bronchopneumonia (BP) in feedlot cattle. Hypothesis/Objectives To assess inter‐rater agreement and reliability of TUS findings in feedlot cattle, with or without naturally occurring BP. Animals Feedlot steers with (n = 210) or without (n = 107) clinical signs of BP that were assessed by TUS in a previous case‐control study. Methods A random sample of 50 TUS videos (16‐s duration) were scored by 6 raters with various levels of TUS expertise. Lung consolidation, comet tail artifacts, pleural irregularity and effusion were scored. Inter‐rater agreement was assessed using raw percentage of agreement (Pa), Cohens and Fleiss’ Kappa (κ), and Gwet agreement coefficient (AC1). Intra‐class correlation (ICC) was determined for variables with continuous measurements (mixed factorial design). Results Median (interquartile range [IQR]) Pa were 0.84 (0.80‐0.89), 0.82 (0.80‐0.87), 0.62 (0.53‐0.67), and 0.82 (0.75‐0.86) for presence of lung consolidation, comet tails, pleural irregularity, and pleural effusion, respectively. For the same lesions, Fleiss κ (95% confidence intervals [CI]) were 0.67 (0.49‐0.86), 0.56 (0.33‐0.80), 0.20 (−0.05 to 0.44), and 0.36 (0.10‐0.61), respectively. AC1 were 0.68 (0.51‐0.86), 0.73 (0.58‐0.89), 0.21 (−0.01 to 0.44), and 0.71 (0.51‐0.92), respectively. Moderate reliability was found among raters for all quantitative variables (ICC ranged from 0.52 to 0.70). Conclusions and Clinical Importance Inter‐rater agreement was good for presence of lung consolidation, comet tails and pleural effusion (based on Pa and AC1) but was slight to poor for pleural irregularity.