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To determine the prevalence ofStudy herds were recruited from the Western Canadian Cow-calf Surveillance Network (WCBlood samples were collected from 20 cows per herd in a systematic random fashion by private veterinarians in the fall of 2014. A serum ELISA (IDEXX, Westbrook, Maine, USA) test was used for the detection of MAP antibodies in the blood samples.The cow level seroprevalence across all 3 provinces was 1.5%. Alberta had the lowest cow seroprevalence (1.3%) followed by Saskatchewan (1.7%), and Manitoba (2.1%). Herd level data showed that 24% of herds had at least 1 positive animal and 5% had at least 2 positive animals. Seroprevalence estimates varied between geographical regions within each province and with herd size.The apparent prevalence of MAP in prairie cow-calf herds remains low and similar to past estimates for the region. However, controlling the spread of Johne's disease in the western Canadian cow-calf herd should be considered an important discussion point in the beef industry.Ongoing surveillance of Johne's disease in western Canadian beef herds is necessary for mitigating disease spread before it becomes a disease of major concern within the industry.Séroprévalence dePour déterminer la prévalence deLes troupeaux à l’étude ont été recrutés à partir du Réseau de surveillance des vaches-veaux de l’Ouest canadien (WCDes échantillons de sang ont été prélevés de 20 vaches par troupeau de façon aléatoire systématique par des vétérinaires en pratique privée à l’automne 2014. Un test ELISA sérique (IDEXX, Westbrook, Maine, États-Unis) a été utilisé pour la détection des anticorps MAP dans les échantillons de sang.La séroprévalence chez les vaches dans les trois provinces était de 1,5 %. L’Alberta avait la plus faible séroprévalence chez les vaches (1,3 %), suivie de la Saskatchewan (1,7 %) et du Manitoba (2,1 %). Les données au niveau du troupeau ont montré que 24 % des troupeaux avaient au moins un animal positif et 5 % avaient au moins deux animaux positifs. Les estimations de la séroprévalence variaient entre les régions géographiques de chaque province et selon la taille du troupeau.La prévalence apparente de la MAP dans les troupeaux de vaches-veaux des Prairies demeure faible et semblable aux estimations antérieures pour la région. Cependant, la maitrise de la propagation de la maladie de Johne dans le troupeau vache-veau de l’Ouest canadien devrait être considérée comme un point de discussion important dans l’industrie bovine.La surveillance continue de la maladie de Johne dans les troupeaux de bovins de boucherie de l’Ouest canadien est nécessaire pour atténuer la propagation de la maladie avant qu’elle ne devienne une maladie préoccupante au sein de l’industrie.(Traduit par D

Bovine respiratory disease (BRD), calf diarrhea (CD), and navel infections are the most commonly reported diseases of western Canadian beef calves. The objectives of this study were to estimate the frequency of treatment for these diseases for specific age cohorts and identify potential opportunities for reducing antimicrobial use. Producers representing 89 western Canadian cow-calf herds completed a survey describing calfhood diseases and management. The most common reason for calf treatment before weaning was BRD (4.9%), and BRD treatment was described in 51% of reporting herds before 2 months of age. Calf diarrhea (2.9%) and navel infection (2.0%) were the second and third most common reasons for treatment. Most calves were treated for CD between 6 days and 1 month of age. Almost one in five herds reported routinely administering antimicrobials at birth. Calving heifers and cows together were all associated with an increased treatment risk for BRD in calves from birth to 2 months (OR 3.55, 95%CI 2.13–5.94, P < 0.0001), CD from 1 month to weaning (OR 3.94, 95%CI 1.29–12.0, P = 0.02), and navel infection (OR 4.55, 95%CI 1.78–11.6, P = 0.002). Failure to sort cow-calf pairs out of the calving area was also associated with an increased treatment risk for BRD from 4 months to weaning (OR 4.89, 95%CI 1.96–12.2, P = 0.0006) and CD from 24 h to 5 days (OR 2.82, 95%CI 1.03–7.75, P = 0.04), and not using the Sandhills system was associated with an increased treatment risk for navel infection (OR 4.55, 95%CI 1.78–11.6, P = 0.002). Other potentially modifiable factors associated with an increased risk of BRD in calves from birth to 2 months were winter feeding and calving in one area (P < 0.0001), heifers calving in a higher density area (P = 0.01), and an increasing number of times cow-calf pairs were gathered before turn out to summer pasture (P = 0.0005). The purchase of any cows during the calving or prebreeding period was associated with an increased risk of BRD from birth to 2 months (P < 0.0001) and from 2 to 4 months (P < 0.0001). A history of respiratory bacterin vaccines administered to the dams was associated with a decreased risk of BRD in calves from 4 months to weaning (P = 0.01). Cows calving in a higher density area was associated with an increased risk of CD from 1 month to weaning (P = 0.02). These practices present opportunities for investigation of approaches to disease management that could support the judicious use of antimicrobials.

Background. Bovine respiratory disease (BRD) is an important cause of morbidity and mortality and is responsible for most of the injectable antimicrobial use in the feedlot industry. Traditional bacterial culture can be used to diagnose BRD by confirming the presence of causative pathogens and to support antimicrobial selection. However, given that bacterial culture takes up to a week and early intervention is critical for treatment success, culture has limited utility for informing rapid therapeutic decision-making. In contrast, metagenomic sequencing has the potential to quickly resolve all nucleic acid in a sample, including pathogen biomarkers and antimicrobial resistance genes. In particular, third-generation Oxford Nanopore Technology sequencing platforms provide long reads and access to raw sequencing data in real-time as it is produced, thereby reducing the time from sample collection to diagnostic answer. The purpose of this study was to compare the diagnostic performance of nanopore metagenomic sequencing to traditional culture and sensitivity methods as applied to nasopharyngeal samples from segregated groups of chronically ill feedlot cattle, previously treated with antimicrobials for nonresponsive pneumonia or lameness. Results. BRD pathogens were isolated from most samples and a variety of different resistance profiles were observed across isolates. The sequencing data indicated the samples were dominated by Moraxella bovoculi, Mannheimia haemolytica, Mycoplasma dispar, and Pasteurella multocida, and included a wide range of antimicrobial resistance genes (ARGs), encoding resistance for up to seven classes of antimicrobials. Genes conferring resistance to beta-lactams were the most commonly detected, while the tetH gene was detected in the most samples overall. Metagenomic sequencing detected the BRD pathogens of interest more often than did culture, but there was limited concordance between phenotypic resistance to antimicrobials and the presence of relevant ARGs. Conclusions. Metagenomic sequencing can reduce the time from sampling to results, detect pathogens missed by bacterial culture, and identify genetically encoded determinants of resistance. Increasing sequencing coverage of target organisms will be an essential component of improving the reliability of this technology, such that it can be better used for the surveillance of pathogens of interest, genetic determinants of resistance, and to inform diagnostic decisions.

This study evaluated in vivo effects of increasing sulfate concentrations of drinking water on dry matter intake (DMI), water intake, ruminal fermentation, and apparent total-tract digestibility, and in vitro effects of water sulfate and bismuth subsalicylate (BSS) dose. Eight ruminal-cannulated beef heifers (382 ± 45 kg) were stratified into two complete and one incomplete 3×3 Latin squares with 28 d periods. Water contained 341 ± 29 (LS), 2,785 ± 71 (MS), or 4,948 ± 163 mg/L (HS) sulfate. Feed and water intake, ruminal fermentation, and nutrient digestibility were evaluated. Ruminal gas samples were collected every 4 h on d 27 to analyze hydrogen sulfide (H2S) concentration. At the end of each period, digesta collected from heifers in the complete Latin squares were used for in vitro incubation to evaluate water sulfate and BSS dose (0.0, 0.2, 0.4, and 0.6% dry matter). Water intake was 7 L/d greater (P < 0.01) for HS than LS, while MS did not differ. Water sulfate did not affect DMI, but total sulfur intake increased with increasing water sulfate concentration (P < 0.01). Heifers drinking MS and HS had greater ruminal H2S for 10.5 h after water provision and HS continued to be greater for another 4 h relative to LS (sulfate hour, P < 0.01). Ruminal SCFA concentration, molar proportions of major acids, and nutrient digestibility were not affected (P≥0.19). There were no interactions between water sulfate and BSS in vitro. In vitro H2S production (µg/48 h) increased with increasing sulfate concentration (P < 0.01) and was reduced (P=0.05) by BSS inclusion. Neutral detergent fiber digestibility was not affected by sulfate or BSS. Increasing water sulfate concentrations did not negatively affect water or feed intake but did increase H2S concentration and production in vivo and in vitro, respectively. Bismuth subsalicylate may be a potential strategy to reduce H2S production.

Computed tomographic (CT) features of lymph nodes are used for diagnosis, staging, and response evaluation in veterinary patients. The objectives of this study were to describe maximum short- and long-axis transverse diameters (SATD and LATD, respectively), volume, and attenuation of presumed normal canine mandibular lymph nodes (MLNs) and medial retropharyngeal lymph nodes (MRLNs), to investigate the effect of variables on these features, and to describe inter-observer reliability of transverse diameter and attenuation measurement. Computed tomography studies of 161 dogs were retrospectively reviewed. Median values for SATD were 5.2 and 5.4 mm, median values for volume were 0.26 and 0.54 cmLes caractéristiques tomodensitométriques (CT) des ganglions lymphatiques sont utilisées pour le diagnostic, la stadification et l’évaluation de la réponse chez les patients vétérinaires. Les objectifs de cette étude étaient de décrire les diamètres transversaux maximaux à axe court et long (SATD et LATD, respectivement), le volume et l’atténuation des ganglions lymphatiques mandibulaires canins (MLN) et des ganglions lymphatiques rétropharyngés médians (MRLN) présumés normaux, afin d’étudier l’effet de variables sur ces caractéristiques, et pour décrire la fiabilité inter-observateur de la mesure du diamètre transversal et de l’atténuation. Des études de tomodensitométrie de 161 chiens ont été examinées rétrospectivement. Les valeurs médianes pour la SATD étaient de 5,2 et 5,4 mm, les valeurs médianes pour le volume étaient de 0,26 et 0,54 cm

Bovine respiratory disease (BRD) is an economically important cause of morbidity and mortality in beef calves. Control of BRD is most often addressed through “homologous” vaccination utilizing the same injectable modified-live viral (MLV) vaccine for both priming and boosting. Heterologous prime-boosting uses different routes and antigenic forms for priming and boosting. Three vaccine protocols were compared: an injectable (IJ) MLV (IJ-MLV) group (IJ-MLV priming at ~48 days and boosted with IJ-MLV at weaning), intranasal (IN) MLV (IN-MLV) group (intranasal priming with MLV at ~24 hours, boosted twice with an IJ-MLV), and intranasal killed viral (IN-KV) group (primed with an IN-MLV at ~24 hours, boosted twice with an IJ-KV). Serum antibody concentrations determined by enzyme-linked immunosorbent assays (ELISAs) were compared and the IN-KV group had significantly higher BRSV-specific antibody concentrations after boosting compared with the 2 homologous groups. No differences in BHV-specific antibody concentrations were observed between any of the groups.

Bovine viral diarrhea virus (BVDV) is an important pathogen causally associated with morbidity and mortality, and production losses in both suckling and weaned beef calves. Vaccination for protection against disease caused by BVDV is challenging because of the inhibitory effect of maternal antibodies; however, it is most convenient for beef producers to vaccinate calves before moving herds to summer pastures. We compared modified live and inactivated vaccines used for priming and boosting beef calves and found that neither type of vaccine results in strong antibody responses in the face of maternal antibodies. These data are generally consistent with previous studies and suggest that alternative protocols using early mucosal delivery followed by parenteral boosting should be examined to improve vaccine efficacy.

The use of metaphylactic antimicrobials to control bovine respiratory disease (BRD) is under increased scrutiny; therefore, effective immunization is becoming a priority. Stimulation of an effective immune response is challenging because calves are often primed with injectable (IJ) vaccines, in the face of maternal antibodies which can interfere with the immune response. Maternal antibody interference may be bypassed with use of intranasal (IN) vaccines. This study represents one of few independent vaccine field trials and it demonstrated no significant differences in post-weaning BRD morbidity/mortality or average daily gain in beef calves primed with either an IN or IJ vaccine.

We conducted a systematic review and network meta-analysis to determine the comparative efficacy of antibiotics used to control bovine respiratory disease (BRD) in beef cattle on feedlots. The information sources for the review were: MEDLINE®, MEDLINE In-Process and MEDLINE® Daily, AGRICOLA, Epub Ahead of Print, Cambridge Agricultural and Biological Index, Science Citation Index, Conference Proceedings Citation Index – Science, the Proceedings of the American Association of Bovine Practitioners, World Buiatrics Conference, and the United States Food and Drug Administration Freedom of Information New Animal Drug Applications summaries. The eligible population was weaned beef cattle raised in intensive systems. The interventions of interest were injectable antibiotics used at the time the cattle arrived at the feedlot. The outcome of interest was the diagnosis of BRD within 45 days of arrival at the feedlot. The network meta-analysis included data from 46 studies and 167 study arms identified in the review. The results suggest that macrolides are the most effective antibiotics for the reduction of BRD incidence. Injectable oxytetracycline effectively controlled BRD compared with no antibiotics; however, it was less effective than macrolide treatment. Because oxytetracycline is already commonly used to prevent, control, and treat BRD in groups of feedlot cattle, the use of injectable oxytetracycline for BRD control might have advantages from an antibiotic stewardship perspective.

Between 2011 and 2016, the number of dairy operations in Canada decreased by 13.3%. Mean herd size increased from 65 to 73 animals per farm. The ratio of older (> 60 years old) to younger (< 31 years old) producers also increased. The age structure of the industry suggests that consolidation will continue for the next decade, which has implications for the provision of veterinary services to dairy operations.

Statistics Canada’s 2016 census data were analyzed to determine the proportion of Canadian cow-calf producers who had adopted the use of 7 different technologies and 2 different grazing/feeding management practices, collectively referred to as “management tools.” The 4 most commonly used management tools were rotational grazing, in-field winter grazing/feeding, smartphones/tablets, and computers/laptops. Differences in the adoption of these technologies by geographical region, number of producers/operations, herd size, operator gender, and operator age were examined using logistic regression. Estimates of the mean proportion of producers in eastern (65%) and western (60%) Canada using rotational grazing were similar (P = 0.24). However, a greater proportion of producers in western Canada versus eastern Canada were using in-field winter grazing/feeding (P < 0.001), smartphones/tablets (P < 0.001), and computers/laptops (P = 0.002). Adoption of all 4 tools was higher on farm operations with ≥ 2 operators versus those with 1 operator (P < 0.001). Larger herd size was associated with higher adoption rates across all 4 management tools. The effect of gender on adoption rates was equivocal.

Four gauges (14G, 16G, 18G, 20G) of single use hypodermic needles were evaluated for sharpness by measuring the force required to puncture rehydrated bovine leather. The needles began to dull after 1 use with maximum bluntness occurring within 4 to 5 uses.

From 2011 to 2016, both the number of cow-calf producers and farm operations in Canada decreased by 12.4%. Furthermore, the current demographics portend a similar or greater loss in the number of producers and farms by the next census (2021). This level of consolidation has implications with respect to veterinary education and how practitioners will service the cow-calf sector.

This study determined whether mineral concentrations in the hooves of cattle with toe tip necrosis syndrome (cases) differed from those of cattle dying of all other causes (controls). Samples were collected over a 2-year period from 16 different feedlots and analyzed for 8 minerals [cobalt (Co), copper (Cu), iron (Fe), magnesium (Mg), manganese (Mn), molybdenum (Mo), selenium (Se), and zinc (Zn)]. Mineral concentrations in the hoof wall and solar horn of the same hoof were poorly correlated; Se was the most correlated (ρ = 0.865; P < 0.001), while Mg (ρ = 0.465; P < 0.001) and Zn (ρ = 0.157; P = 0.053) were the least correlated. The cases had significantly lower Mg concentrations in both the hoof wall and solar horn tissue compared to the control subjects. For every 10 ppm decrease in Mg, the odds of a diagnosis of toe tip necrosis syndrome (TTNS) increased by 1.13 times for the hoof wall (P = 0.002) and 1.21 times for solar horn (P < 0.001).

The objective of this study was to provide contemporary data on the epidemiology of gastrointestinal nematode parasite infections of grazing yearling beef cattle in the province of Saskatchewan. Fecal samples (n = 1290) were collected over 4 time periods during the summer grazing season from 21 separately managed groups of cattle. Fecal egg counts (FEC) were estimated using generalized estimating equations with a negative binomial distribution with log link function, adjusting for clustering of samples within each herd for each time period. Nematodirus spp. and Trichuris spp. eggs were enumerated separately and were detected in 5.7% (73/1290) and 1.7% (22/1290) of samples, respectively. One or more strongyle-type eggs were detected in 79.5% (1025/1290) of the samples and FEC increased by 2.8 times over the summer grazing season. Interestingly, FEC were ~3.4 times higher on pastures located in dark brown versus brown soil zones, a finding that warrants further investigation.

A blinded randomized controlled trial was used to evaluate a multi-modal therapeutic regime for treatment of beef bulls infected with Campylobacter fetus subsp. venerealis (Cfv). Treatment included 2 doses of a commercially available monovalent vaccine and long-acting oxytetracycline applied twice at a 2-week interval with treatment completed 2 weeks before post-treatment observation. Fifteen confirmed Cfv infected bulls were randomly allocated to control (n = 8) or treatment groups (n = 7). Preputial scrapings were collected each week from before infection to 11 weeks following the last treatment. When the polymerase chain reaction (PCR) results for both culture and preputial scrapings were interpreted in parallel, there were no significant differences between treated and untreated bulls. Regardless of the type of diagnostic testing considered, treatment with 2 label doses of this regime did not stop shedding of Cfv in all treated bulls and is, therefore, not recommended as an effective management strategy.

This study investigated the relationship between treatment protocol, survival to discharge, and relapse in 46 dogs diagnosed with primary immune-mediated thrombocytopenia (ITP) at the Western College of Veterinary Medicine between 2000 and 2013. Treatment was at the discretion of the attending clinician and consisted of either a corticosteroid alone or a corticosteroid plus a secondary therapy. There was no association between survival to discharge and treatment protocol (P = 0.23). Of the surviving in-patients, 39% experienced a relapse. Our study failed to show a significant difference in survival and relapse based on treatment protocol.

To compare the performance of horses with intermittent dorsal displacement of the soft palate (IDDSP) treated surgically with a control group and to determine whether there was a difference in postoperative performance between horses treated with a staphylectomy or a tie-forward procedure.A retrospective observational study.Swedish Warmblood trotting horses (Standardbreds) with endoscopically confirmed IDDSP (n=56) and control horses (n=48) with endoscopically normal upper airways tested using overground endoscopy identified from medical records.Generalized estimating equations that accounted for repeated measurements were used to compare presurgery and postsurgery racing performance (speed, m/s) of IDDSP horses, and to compare their performance to control horses. Similarly, the effects of surgical procedure type on whether horses returned to racing, postsurgical speed, career race starts and earnings were evaluated.There was no significant difference in race speed between IDDSP and control horses at any time point. The percentage of horses racing postoperatively, the number of career races, and career earnings did not differ between staphylectomy treated and tie-forward treated horses, nor between IDDSP and control horses.In our study there was no difference in the postoperative outcomes between the two surgical techniques used to treat definitively diagnosed IDDSP. These results find no strong evidence to promote use of one technique over another in the treatment of this condition.

Saskatchewan cow-calf producers (n = 2000) were surveyed to determine what factors were associated with their uptake of veterinary services; how and where they access nutritional information and animal health advice; and whether they were comfortable with having non-veterinarians perform veterinary procedures. The survey response rate was 18.1%. Veterinarians were seen as a primary source of nutritional information and animal health advice. Over the past decade producers have shifted their veterinary service usage from individual animal events to herd-level procedures. Producers who pregnancy check were more likely to be large producers (OR = 1.9; 95% CI = 1.2 to 3.1; P = 0.007), to semen test their bulls (OR = 3.4; 95% CI = 2.0 to 5.8: P < 0.001), analyze their forages (OR = 2.3; 95% CI = 1.7 to 4.0; P = 0.006), and to farm in the brown versus the gray or dark brown soil zones (P = 0.004). Most (94.0%) respondents had adequate veterinary services within an hour’s drive of the farm and 90.4% were satisfied with their veterinary service provider. Approximately 25% of respondents would be comfortable with having a non-veterinarian pregnancy check and attend to prolapses.

The primary objective of this study was to investigate whether rider experience influences the assessment and grading of lameness in horses based on under-saddle gait analysis. Thirteen adult sports horses in active training were included in the study. After a baseline lameness and neurologic examination by the principal investigators, horses were videotaped while being ridden by an experienced and a less experienced rider. A 3-minute video was made for each horse and rider and 26 videos were randomly ordered and compiled on a DVD. Veterinarians with different levels of experience in evaluating lameness and veterinary students viewed the DVD and assigned a lameness score to each horse/rider combination. In a model accounting for the expertise of the evaluator, there was no difference in overall lameness scores between experienced and less experienced riders. This result was consistent for both sound and unsound horses. The overall lameness scores reported by specialists and students, however, differed significantly. The lameness score reported by the study participants while the horse was ridden was significantly associated with the subjective baseline lameness assessment reported by the principal investigators for the same limb when the horse was not under saddle. Additional work is necessary to determine whether riders with even lower skill levels would further alter the balance and motion pattern of the horse and have more influence on subjective grading of lameness.L’objectif principal de la présente étude était d’examiner si l’expérience du cavalier influence l’évaluation et la gradation de la boiterie chez des chevaux basées sur l’analyse de la démarche sous-selle. Treize chevaux sportifs adultes en entraînement actif ont été inclus dans l’étude. Suite à un examen neurologique et de boiterie de base par les chercheurs principaux, les chevaux ont été filmés alors qu’ils étaient montés par un cavalier d’expérience et un cavalier moins expérimenté. Une vidéo de 3 minutes a été réalisée pour chaque combinaison cheval/cavalier et les 26 vidéos ont été compilées de manière aléatoire sur un DVD. Des vétérinaires ayant différents niveaux d’expérience à évaluer les boiteries et des étudiants vétérinaires ont visualisé le DVD et donné un pointage à chaque combinaison cheval/cavalier. Dans un modèle tenant compte de l’expérience de l’évaluateur, il n’y avait aucune différence dans les pointages globaux entre un cavalier expérimenté et un moins expérimenté. Ce résultat était constant autant pour les chevaux solides que fragiles. Toutefois, les pointages globaux de boiterie notés par les spécialistes et les étudiants étaient significativement différents. Le pointage de boiterie rapporté par les participants à l’étude alors que le cheval était conduit était significativement associé avec l’évaluation subjective de base rapportée par les chercheurs principaux pour le même membre lorsque le cheval n’était pas sous-selle. Des études additionnelles sont nécessaires afin de déterminer si des cavaliers avec encore moins d’expérience influenceraient encore plus l’équilibre et le patron de mouvement du cheval et aurait plus d’influence sur la gradation subjective de la boiterie.(Traduit par Docteur Serge Messier).

A new real-time quantitative polymerase chain reaction (qPCR) test was used to diagnose Campylobacter fetus subsp. venerealis infection associated with dramatic reproductive losses in a commercial cow-calf herd. The results were verified with repeated culture, phenotypic characterization of the organism and DNA sequencing. This case demonstrates the need for a practical field test for C. fetus subsp. venerealis and the importance of considering this organism as a potential cause of pregnancy failure in beef herds.

Cow-calf producers in western Canada were surveyed in June 2010 regarding calf-hood diseases and veterinary service usage; 310 producers responded. Use of veterinary services, particularly herd-health related services, increased with herd size as did neonatal diarrhea and clostridial vaccine usage. Administration of clostridial vaccines to pregnant dams before calving was associated with a reduction in neonatal diarrhea treatments; however, there was no association between neonatal diarrhea vaccine usage and a reduction in diarrhea treatments. Producers with > 220 breeding females were more likely than those with < 85 breeding females to seek veterinary advice regarding treating sick calves, have a veterinarian necropsy dead calves, have a veterinarian pregnancy check their bred females, and evaluate their herd bulls for breeding soundness.

This study describes biological hazards reported by veterinarians working in western Canada obtained through a self-administered mailed questionnaire. The potential occupational hazards included as biological hazards were zoonotic disease events, exposure to rabies, injuries due to bites and scratches, and allergies. Only 16.7% (136/812) of responding veterinarians reported the occurrence of a zoonosis or exposure to rabies in the past 5 years; the most commonly reported event was ringworm. Most bites and scratches (86%) described by 586 veterinarians involved encounters with cats; 81% of the resulting 163 infections were due to cat bites or scratches. Approximately 38% of participants reported developing an allergy during their career, with 41% of the affected individuals altering the way they practiced in response to their allergy.

Bovine respiratory syncytial virus (BRSV) is a primary agent of pneumonia in calves that causes damage to pulmonary epithelium and results in respiratory distress. This retrospective cumulative analysis of data from 681 calves experimentally infected with BRSV was undertaken to determine if there was an association of both the partial pressure of oxygen in arterial blood (PaO₂) and the lactate concentration in arterial blood with lung lesion severity, as well as to estimate the potential predictive value of these 2 parameters in assessing disease progression. The PaO₂ was highly significantly associated with the extent of lung lesions and was considered highly predictive of lesion severity. Although the arterial blood lactate concentration was also significantly associated with lung disease, the results were not consistent for all days after challenge. Also, the lactate level was usually within the reference interval. Thus, the usefulness of the arterial blood lactate concentration in predicting the course of BRSV-associated pneumonia is limited in the clinical setting.Le virus respiratoire syncitial bovin (BRSV) est un agent primaire de pneumonie chez les veaux qui cause des dommages à l’épithélium pulmonaire résultant en une détresse respiratoire. Cette analyse cumulative rétrospective des données provenant de 681 veaux infectés expérimentalement avec le BRSV a été entreprise afin de déterminer s’il y avait une association entre la pression partielle en oxygène dans le sang artériel (PaO

This paper reports physical, psychological, and chemical hazards relevant to western Canadian veterinarians as obtained by a self-administered mailed questionnaire. Nine-three percent (750/806) of veterinarians reported some form of injury during the previous 5 years; 17% of respondents (131/791) indicated injuries that resulted in 1 or more days off work. Median stress levels were similar across work environments; overall, 7% (57/813) indicated either no stress or severe stress, while 53% (428/813) indicated moderate stress. Twenty percent (3/15) of food animal practitioners and 37% (114/308) of companion animal practitioners who took X-rays reported accidental exposure. Accidental exposure to gas anesthetic was reported by 69% (394/570) of those in private practice. Exposure to chemicals occurred in all work environments. Veterinarians in western Canada are at risk of minor to severe injury due to both animal and non-animal related causes.

In 2006, an outbreak of anthrax in Saskatchewan affected several species but most of the losses occurred in cattle. Potential risk factors contributing to this outbreak were investigated through questionnaires involving 117 case farms and 259 control farms geographically representative of the Saskatchewan beef herd. The occurrence of flooding [odds ratio (OR) = 3.4; 95% confidence interval (CI): 1.8 to 6.4], wetter pastures (Good: OR = 3.5; 95% CI: 1.4 to 8.5; Wet: OR = 7.2; 95% CI: 2.9 to 18.1), shorter pasture grass length (OR = 3.0; 95% CI: 1.4 to 6.4), and higher density of the animals on pasture (OR = 3.0; 95% CI: 1.6 to 5.7) were more likely to have been reported for case herds than for control herds. Case farms were more likely than control farms to have vaccinated more than 1 week after the first reported case in the rural municipality (OR = 6.3; 95% CI: 2.6 to 15.3). Timing of vaccination in case herds was also significantly associated with the occurrence of subsequent deaths on these farms (P = 0.001).

An outbreak of anthrax in Saskatchewan in 2006 affected more than 800 animals at 150 locations. The purpose of this study was to assess the spatial and temporal patterns among the cases to determine if there were any significant trends associated with this outbreak. Case and population data were first analyzed for each individual farm location and then again as aggregate data per rural municipality using spatial and spatiotemporal statistical methods such as Oden’s Ipop, Cuzick-Edwards’ test, spatial scan test, and other mapping techniques. East central Saskatchewan was identified as a primary high risk area, particularly during July 2006. The results of the study led to the conclusion that within this high-risk region, flooding in spring followed by hot and dry conditions could have been a factor in the development of the outbreak.

Among grow-to-finish pigs from 10 herds in Alberta and Saskatchewan, 23 (16%) of 144 fecal samples were culture-positive and 40 (28%) of 144 pigs were seropositive for Salmonella. With a Bayesian model specifying dependence between the 2 tests, the sensitivity (Se) of culture and real-time polymerase chain reaction (RT-PCR) was 79% to 86%, depending on the cut-off value for the enzyme-linked immunosorbent assay (ELISA). Culture specificity (Sp) was assumed to be 100%; RT-PCR Sp was found to be 94%. The ELISA Se was 76% and 51% at optical density cut-off values ≥ 20% and ≥ 40%, respectively; the Sp was 94% at each cut-off value. The model showed some sensitivity to ELISA prior information, the ELISA Se being approximately 8% lower when informative prior information was specified in the model. When there was no adjustment for dependence between culture and RT-PCR, the posterior estimates for both culture and RT-PCR Se were 11% higher than with the conditional-dependence model and had considerably narrower probability intervals, which suggests that correlation between culture and PCR is important and should be adjusted for in future studies.

The objective of this study was to develop a model using equine data from geographically limited surveillance locations to predict risk categories for West Nile virus (WNV) infection in horses in all geographic locations across the province of Saskatchewan. The province was divided geographically into low-, medium-, or high-risk categories for WNV, based on available serology information from 923 horses obtained through 4 studies of WNV infection in horse populations in Saskatchewan. Discriminant analysis was used to build models using the observed risk of WNV in horses and geographic division-specific environmental data as well as to predict the risk category for all areas, including those beyond the surveillance zones. High-risk areas were indicated by relatively lower rainfall, higher temperatures, and a lower percentage of area covered in trees, water, and wetland. These conditions were most often identified in the southwest corner of the province. Environmental conditions can be used to identify those areas that are at highest risk for WNV. Public health managers could use prediction maps, which are based on animal or human information and developed from annual early season meteorological information, to guide ongoing decisions about when and where to focus intervention strategies for WNV.

The study objectives were to investigate Salmonella prevalence, serovar distribution, and risk factors for shedding in 10 purposively selected farrow-to-finish farms in Saskatchewan and Alberta. Pooled fecal samples from the breeding and grow-finish phases and individual fecal samples from breeding, nursery, and grow-finish pigs were cultured for Salmonella; serotyping of isolates was performed. Pig and pen characteristics were recorded for each pig and pen sampled.Overall, 407/1143 (36%) of samples were Salmonella positive; within-farm prevalence ranged from 1% to 79%. Sows, nursery, and grow-finish pigs accounted for 43%, 29%, and 28% of positive samples, respectively. More Salmonella were detected in pooled pen than individual pig samples (P0.001). Among 418 Salmonella isolates, there were 19 distinct serovars; the most common were S. Derby (28.5%), S. Typhimurium, var. Copenhagen (19.1%), S. Putten (11.8%), S. Infantis (6.8%), and S. Mbandaka (6.1%). Sows were more likely to shed Salmonella than nursery or grow-finisher (OR 2.9, P0.001) pigs. Pelleted feed (OR 8.2, P0.001) and nose-to-nose pig contact through pens (OR 2.2, P = 0.005) were associated with increased Salmonella prevalence. Significant differences in serovar distribution were detected among production phases. The use of pooled pen samples is recommended as a more efficient means for accurate evaluation of Salmonella status in different phases of pig production. The breeding herd might be an important source of Salmonella persistence within farrow-to-finish farms and should be targeted in control efforts. The latter might also apply to the use of pelleted feed, which remains the most consistently reported significant risk factor for Salmonella shedding in pigs.

This fecal prevalence study targeted cattle from 7 large (10 000 to > 40 000 head) commercial feedlots in Alberta as a means of establishing Campylobacter levels in cattle just prior to animals entering the food chain. Overall, 87% [95% confidence interval (CI) = 86–88] of 2776 fresh pen-floor fecal samples were culture positive for Campylobacter species, with prevalences ranging from 76% to 95% among the 7 feedlots. Campylobacter spp. prevalence was 88% (95% CI = 86–90) in the summer (n = 1376) and 86% (95% CI = 85–88) in the winter (n = 1400). In addition, 69% (95% CI = 66–71) of 1486 Campylobacter spp. positive samples were identified as Campylobacter jejuni using hippurate hydrolysis testing. Of those, 64% (95% CI = 58–70) of 277 and 70% (95% CI = 67–72) of 1209 Campylobacter isolates were identified as C. jejuni in winter and summer, respectively. After accounting for clustering within pen and feedlot, feedlot size and the number of days on feed were associated with Campylobacter spp. isolation rates. The high isolation rates of Campylobacter spp. and C. jejuni in feedlot cattle feces in this study suggest a potential role for feedlot cattle in the complex epidemiology of campylobacters in Alberta.

A disease syndrome characterized by hemolysis, methemoglobinemia, methemoglobinuria, and death was observed in a herd of purebred Limousin beef cattle grazing on pasture in November in Alberta. Improper disposal of the nonselective herbicide, sodium chlorate, was identified as the causal agent. Highly variable blood methemoglobin levels reflected differences in herbicide consumption.

The primary objectives of this study were to determine the seroprevalence of West Nile virus (WNV) infection of horses in Saskatchewan in 2003 and to identify risk factors for the infection. Blood samples were collected in August and October from 212 horses in 20 herds in 5 geographic zones. After accounting for within-herd clustering, the proportion of horses that had been infected with WNV, as determined by IgG and IgM antibody response, was 55.7% (95% confidence interval, 44.9% to 65.8%). The proportion of antibody-positive horses differed among herds (0% to 100%) and across ecoregions (20% to 76%). Horses in southern ecoregions were more likely to have either IgM antibodies or IgG concentrations suggesting infection than were horses in northern ecoregions. The use of mosquito-control measures was associated with decreased risk. After accounting for ecoregion, there was no difference between recipients of an inactivated WNV vaccine and nonrecipients in the occurrence of antibodies reflecting natural infection.

Groups (5 to 15 per group) of gnotobiotic swine were infected oronasally with porcine circovirus type 2 (PCV2) at 3 days of age and then given 1 of 6 different commercial Mycoplasma hyopneumoniae (M. hyopneumoniae) bacterins as either a single dose (7 d of age, 1 application products) or 2 doses (7 and 21 d of age, 2 application product). Control groups received PCV2 alone (n = 9) or were infected with PCV2 and immunized twice with keyhole limpet hemocyanin (KLH) emulsified in incomplete Freund’s adjuvant (ICFA) (n = 7). Five of 7 (71%) PCV2-infected piglets immunized with KLH/ICFA developed mild or overt PMWS, whereas none of 9 piglets infected with PCV2 alone developed PMWS. Five of 12 (42%) piglets vaccinated with a commercial bacterin containing mineral oil adjuvant developed PMWS following vaccination. None of the PCV2-infected piglets in the other bacterin-vaccinated groups developed PMWS in this model of PCV2-associated disease. This difference in prevalence of PMWS in piglets given the mineral oil-adjuvanted M. hyopneumoniae bacterin and the other M. hyopneumoniae bacterin vaccination groups was statistically significant (P < 0.05).

The purpose of this retrospective study was to identify factors associated with quill injury in dogs. A second objective was to determine the risk of complications and any factors that would predict the likelihood of complications. Hospital records of 296 porcupine quill injuries in dogs from 1998 to 2002 were studied. There was an increased occurrence of porcupine encounters in the spring and fall months; Siberian huskies, rottweilers, and German shepherd crosses were significantly overrepresented for quill injuries. There was no association between risk of complications and either number of quills or antimicrobial use. Increasing time between quill injury and presentation was associated with an increased risk of complications. Because of the increased frequency of complication with a longer interval until presentation, clients should be strongly encouraged to bring the dog in as soon as the quill injury is discovered. Patients presented after 24 hours should be monitored closely during the first 3 weeks after injury, as most complications occurred during this time.

The objective of this study was to determine whether a commercially available, saponin-adjuvanted, inactivated bovine respiratory syncytial virus (BRSV) vaccine would protect calves from experimental infection with virulent BRSV. This was a randomized controlled trial comprising 14, 8- to 9-week-old calves seronegative for BRSV. Group 1 calves (n = 8) were not vaccinated and group 2 calves (n = 6) were vaccinated on days 0 and 19 with an inactivated BRSV vaccine. All calves were challenged with virulent BRSV on day 46. Clinical signs, arterial PO2, and immune responses were monitored after challenge. Calves were euthanatized on day 54 (8 d after challenge) and lungs were examined for lesions. Vaccination elicited increases in BRSV-specific immunoglobulin (Ig) G and virus neutralizing antibody titers. Challenge with BRSV resulted in severe respiratory tract disease and extensive pulmonary lesions in control calves, but no signs of clinical disease and minimal or no pulmonary lesions in vaccinated calves. Arterial blood oxygen values on day 53 (7 d after challenge) in control calves were significantly lower than those in vaccinated calves, which remained within normal limits. Control calves shed BRSV for several days after challenge, whereas BRSV was not detected on deep nasal swabs from vaccinated calves. In summary, the results indicated that this inactivated BRSV vaccine provided clinical protection from experimental infection with virulent virus 27 d after vaccination and significantly decreased the prevalence and severity of pulmonary lesions. Efficacy was similar to that reported for other commercial inactivated and modified-live BRSV vaccines.

A study was conducted in Alberta to determine the seroprevalence of Neospora caninum in feedlot calves purchased from various auction markets throughout western Canada. Four feedlots (1 feedlot from each of the Airdrie and High River areas and 2 feedlots from the Strathmore area) were selected for sampling. At each feedlot, a random 10% sample of feedlot steer and bull calves entering the feedlot from September 2001 to December 2001 were enrolled in the study until there were a maximum of 500 animals enrolled per feedlot. Blood samples were collected from 1976 male animals at the time of entry to the 4 study feedlots. The animals represented 375 groups purchased from 70 sale points throughout British Columbia, Alberta, Saskatchewan, and Manitoba. Of the 1976 animals tested, 128 animals tested positive for antibodies to N. caninum. The prevalence and adjusted 95% confidence limits for N. caninum in beef calves on entrance to the feedlot in western Canada were 6.5% (95% CI, 5.1 to 8.2). There were no significant (Por = 0.05) associations between the risk of treatment, the risk of designation as "chronic," and the risk of death and antibodies to N. caninum either before or after adjusting for feedlot, entry weight, entry date, and clustering of disease within lots at each feedlot. In addition, there was no significant (Por = 0.05) association between serological status and feedlot entry weight or average daily gain. Note that there was no information available on feed conversion because the calves were mixed within existing commercial feedlot pens and the actual feed intake of each animal could not be determined. Adjustment for the concentration of antibodies to bovine viral diarrhea virus on arrival did not change any of the examined associations between N. caninum status and calf health or performance. The results of this study demonstrated that the prevalence of N. caninum in feedlot calves in western Canada was less than the prevalence reported in the United States. Additional studies are required to determine whether the inferior rate of gain and feed efficiency observed in the southern United States with animals testing positive for antibodies to N. caninum also occurs under the management conditions used in western Canada.