Interpretation of cerebrospinal fluid analysis from recumbent cows using different thresholds of red blood cell count.

BACKGROUND: Hemodilution of the cerebrospinal fluid (CSF) could confound interpretation of results. Accurately predicting total nucleated cells count (TNCC) and total protein concentration (TPC) attributable to hemodilution is difficult. OBJECTIVE: To determine the effects of hemodilution on TPC and TNCC in bovine CSF. METHODS: Retrospective review of CSF analysis results of downer dairy cows treated at Centre hospitalier universitaire vétérinaire between January 2006 and December 2014. Descriptive statistics were performed using 3 scenarios. RESULTS: Among the 235 samples included, red blood cell (RBC) count (RBCC) ranged from 0 to 869 220 RBC/µL (median = 6.6), TPC ranged from 0.04 to 6.51 g/L (median = 0.27), and TNCC ranged from 0 to 7500 cell/µL (median = 1.1). Among the 157 samples that had <30 RBC/µL (a threshold used in other species), TPC and TNCC varied between 0.13 and 1.06 g/L (median = 0.27) and between 0 and 31.4 cell/µL (median = 0.6), respectively. Eighty-four samples had TPC <0.25 g/L and TNCC ≤4.5 cell/µL. Among those 84 samples, RBCC varied between 0 and 1290 RBC/µL (median = 4.7). In 20 samples, TNCC was 0 with a variation in RBCC between 0 and 840 RBC/µL (median = 3.9). No strong correlations between RBCC and TNCC and TPC were found. CONCLUSIONS: A cutoff around 200 RBC/µL is proposed as clinically meaninful in bovine CSF. Results between 200 and 1290 RBC/µL are equivocal.

Survival and prognostic indicators in downer dairy cows presented to a referring hospital: A retrospective study (1318 cases).

BACKGROUND: Downer cow syndrome, a common problem in dairy cattle, represents a diagnostic and therapeutic challenge for the attending veterinarian. Identifying prognostic indicators and assessing the odds of survival may improve the accuracy of the clinician's prognosis at the time of diagnosis. OBJECTIVE: To describe a population of downer dairy cows referred to a hospital and investigate predictors of outcome. ANIMALS: Recumbent adult dairy cows (cows unable or unwilling to stand without help) treated at a referral hospital. METHODS: Data at the time of admission were collected from medical records of downer dairy cows treated at the Centre Hospitalier Universitaire Vétérinaire between 1994 and 2016. Simple and multivariable logistic regression analyses were performed to assess the association of predictors with the outcome. RESULTS: Among 1318 cows included, 727 (55%) cows were discharged, and 591 (45%) cows died or were euthanized. Cows with longer time of recumbency before referral (odds ratio [OR] = 3.6), tachycardia (100-120 beats per minute [bpm], OR = 1.93; >120 bpm, OR = 2.92), tachypnea (OR = 1.76), hypothermia (OR = 2.08), anemia (OR = 3.30), neutropenia (OR = 1.7), high aspartate aminotransferase activity (500-1000 U/L, OR = 2.16; >1000 U/L, OR = 6.69), and increased serum creatinine concentration (OR = 1.75) had higher odds of nonsurvival. CONCLUSIONS AND CLINICAL IMPORTANCE: These findings may help the practitioner to consider treatment options and decide if referral is likely beneficial based on the odds of success. Early recognition of low chance of survival may facilitate an early decision for euthanasia.

Risk factors associated with Mycobacterium avium subsp. paratuberculosis herd status in Québec dairy herds.

Paratuberculosis is a chronic and contagious enteric disease of ruminants caused by Mycobacterium avium subsp. paratuberculosis (MAP). Control of paratuberculosis is justified given the associated economic losses and the potential role of MAP in Crohn's disease in humans. Management practices that limit exposure of susceptible animals to MAP are more effective at reducing disease prevalence than testing and culling infected cows. The objective of this retrospective case-control study was to study the association between management practices and MAP status in dairy herds in Québec, Canada. A total of 26 case herds (MAP had been isolated from at least 1 environmental sample in each herd) and 91 control herds (no clinical cases of paratuberculosis and negative on 2 consecutive yearly environmental samplings) were selected among herds enrolled in the Québec Voluntary Paratuberculosis Control Program. A risk assessment questionnaire, completed at enrolment, was available for the selected herds. Culture of MAP was achieved using liquid media and the BACTEC 960 detection system. Multivariable logistic regression was used to evaluate the association between selected risk factors and MAP herd status. Herd size (OR = 1.17; 95% CI: 1.02-1.33) and proportion of cows purchased per year in the last 5 years (OR = 5.44; 95% CI: 1.23-23.98) were significantly associated with a positive MAP herd status. The management risk factors identified in the present study are in accord with previous studies. Management practices aiming to prevent the introduction of new animals into the herd and to reduce the contact of newborn calves with adult animals or their feces are key elements to minimize MAP introduction and transmission into a herd. These elements should be prioritized in control programs.