Comparison of hand-sewn and oversewn stapled jejunojejunal anastomoses in horses.

The objective of this study was to compare the biomechanical properties of hand-sewn jejunojejunal anastomoses to those of oversewn stapled jejunojejunal anastomoses. Jejunojejunal anastomoses were constructed from harvested jejunal segments using a single-layer Lembert technique (1HS), double-layer simple continuous/Cushing technique (2HS), stapled side-to-side technique oversewn with Cushing pattern (SS), and closed 1-stage stapled functional end-to-end technique oversewn with Cushing pattern (FEE). Anastomosed segments were distended with fluid until the point of biomechanical failure. The 2HS had the longest construction time of all anastomoses. Bursting pressures were significantly higher for hand-sewn jejunojejunostomies than those for oversewn stapled jejunojejunostomies. No significant differences were found in bursting pressures between 1HS and 2HS or between SS and FEE. Hand-sewn jejunojejunostomies proved to be biomechanically stronger than oversewn stapled jejunojejunostomies when initially constructed. However, all anastomotic types would be secure techniques to be used clinically based on the supraphysiological pressures they are capable of withstanding.

Comparaison des anastomoses jéjuno-jéjunales cousues à la main et agrafées et cousues chez les chevaux. Cette étude avait pour objectif de comparer les propriétés biomécaniques des anastomoses jéjuno-jéjunales cousues à la main et celles des anastomoses jéjuno-jéjunales agrafées et cousues. Des anastomoses jéjuno-jéjunales ont été construites à partir de segments jéjunaux prélevés en utilisant la technique Lembert à couche unique (1HS), la technique Cushing à double couche simple continue (2HS), la technique agrafée côte à côte selon la méthode Cushing (SS) et la technique fonctionnelle de bout en bout fermée en 1 étape avec couture selon la méthode Cushing (FEE). Des segments anastomosés ont été dilatés avec du liquide jusqu'au point de défaillance biomécanique. La technique 2HS présentait le temps de construction le plus long de toutes les anastomoses. Les pressions de rupture étaient significativement supérieures pour les jéjuno-jéjunostomies cousues par rapport aux jéjuno-jéjunostomies agrafées et cousues. Aucune différence significative n'a été constatée au niveau des pressions de rupture entre 1HS et 2HS ou entre SS et FEE. Les jéjuno-jéjunostomies cousues à la main se sont avérées plus fortes sur le plan mécanique que les jéjuno-jéjunostomies agrafées et cousues lors de la construction initiale. Cependant, tous les types anastomotiques seraient des techniques sûres pour utilisation clinique en se basant sur les pressions supra-physiologiques qu'elles sont capables de supporter.(Traduit par Isabelle Vallières).

Effect of Arthroscopic Lavage on Systemic and Synovial Fluid Serum Amyloid A in Healthy Horses.

OBJECTIVE: To evaluate the effect of arthroscopic lavage on systemic serum amyloid A (SAA) and SAA, total protein, nucleated cell count, and percentage of neutrophils in synovial fluid in healthy horses. STUDY DESIGN: Prospective experimental study. ANIMALS: Healthy adult horses (n = 6). METHODS: Middle carpal joints were randomly assigned to 1 of 2 treatments: arthrocentesis (controls) or arthroscopic lavage, with 30 day washout period between treatments. Synovial fluid and blood samples were collected at 0, 24, 48, 72, 96, and 120 hours. Measurements included systemic and synovial fluid SAA, as well as total protein, nucleated cell count, and percentages of neutrophils in synovial fluid. Data were analyzed by median quantile regression and Wilcoxon signed-rank test and significance level set at P < .05. RESULTS: Systemic and synovial fluid SAA did not increase from baseline (except systemic SAA at 24 hours for both treatments) and were not significantly different between treatments. Total protein values were significantly increased after arthroscopic lavage (except at 96 hours) but not in controls at all time points. With both treatments, nucleated cell counts significantly increased from baseline values at all time points. Percentages of neutrophils were significantly increased after arthroscopic lavage at all time points, but only at 24 hours in controls. CONCLUSION: Total protein, nucleated cell count, and percentage of neutrophils in synovial fluid were significantly increased after arthroscopic lavage; however, synovial fluid SAA was not affected by this procedure. Further research is warranted to validate synovial fluid SAA as a monitoring tool during treatment of septic arthritis.

Survey of Saskatchewan beef cattle producers regarding management practices and veterinary service usage.

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.

Sondage auprès des producteurs de bétail de la Saskatchewan concernant les pratiques de gestion et le recours aux services vétérinaires. On a sondé des éleveurs-naisseurs de la Saskatchewan (n = 2000) afin de déterminer les facteurs associés à leur recours aux services vétérinaires; comment et où ils ont accès à des renseignements nutritionnels et à des conseils sur la santé animale et s'ils étaient à l'aise avec l'idée que des non-vétérinaires réalisent des interventions vétérinaires. Le taux de réponse au sondage était de 18,1 %. Les vétérinaires étaient perçus comme la principale source en matière d'information nutritionnelle et de conseils sur la santé animale. Au cours de la dernière décennie, les éleveurs ont modifié leur utilisation des services vétérinaires pour passer des événements touchant des animaux individuels à des interventions au niveau du cheptel. Les éleveurs qui effectuent une évaluation de la gestation étaient le plus probablement de grands producteurs (fréquence = 1,9; IC de 95 % = 1,2 à 3,1; P = 0,007), ceux qui effectuaient aussi les épreuves de sperme de leurs taureaux (fréquence = 3,4; IC de 95 % = 2,0 à 5,8 : P < 0,001), qui analysaient leur fourrage (fréquence = 2,3; IC de 95 % = 1,7 à 4,0; P = 0,006) et qui cultivaient dans les zones de sol brun par opposition aux zones de sol gris ou brun foncé (P = 0,004). La plupart (94,0 %) des répondants disposaient de services vétérinaires adéquats dans un rayon d'une heure de route de la ferme et 90,4 % étaient satisfaits de leur prestataire de services vétérinaires. Environ 25 % des répondants étaient à l'aise qu'un non-vétérinaire surveille la gestation et s'occupent des prolapsus.(Traduit par Isabelle Vallières).

Ex vivo comparison of the biomechanical properties of hand-sewn and stapled jejunoileal anastomoses in horses.

OBJECTIVE: To compare bursting strength, construction time, and anastomotic dimensions of 4 jejunoileal anastomotic techniques. STUDY DESIGN: Experimental ex vivo study. ANIMALS: Adult horses (n = 12). METHODS: Jejunoileal anastomoses were constructed from harvested ileal and distal jejunal segments using a single-layer Lembert technique (1HS), double-layer simple continuous/Cushing technique (2HS), stapled side-to-side technique (SS), or stapled functional end-to-end technique (FEE). Anastomotic construction time was recorded. Bursting pressures (BP), bursting wall tension (BWT), percentage of mean anastomotic luminal diameter reduction, percentage of luminal diameter reduction relative to adjacent ileal and jejunal diameters and stomal length, were calculated. RESULTS: FEE had the shortest construction time. BP of 1HS and 2HS was significantly higher than FEE and SS (P < .001), which were not different from each other (P = .67). There were no significant differences in BP (P = .25) and BWT (P = .21) between 1HS and 2HS. Mean luminal diameter reduction was less for 1HS (25.1%) than for 2HS (34.8%), however, not statistically different (P = .12). Luminal diameter reduction relative to ileal diameter was significantly less for 1HS (15.2%) than for 2HS (28.47%; P = .012). Luminal diameter reduction relative to jejunal diameter was less for 1HS (32.4%) than 2HS (44.6%) but not statistically different; P = .07). Stomal length was significantly larger for SS (9.93 cm) than FEE (7.32 cm; P = .0002). CONCLUSION: 1HS and 2HS jejunoileal anastomosis are equal in strength; however, 1HS results in less relative luminal diameter reduction. SS and FEE have comparable strength but fail at significantly lower BPs than hand-sewn jejunoileal anastomoses.

The effect of antimicrobial treatment and preventive strategies on bovine respiratory disease and genetic relatedness and antimicrobial resistance of Mycoplasma bovis isolates in a western Canadian feedlot.

Feedlot calves (n = 3784) were systematically randomized and allocated in a 2 × 2 factorial study to receive metaphylactic oxytetracycline (OTC) on arrival or no antimicrobial, as well as florfenicol once subcutaneously or twice intramuscularly (48 h apart) if diagnosed with bovine respiratory disease (BRD). Calves of different treatment groups were comingled and followed from placement to re-implantation (~100 days). Animals receiving OTC had a reduced risk of BRD, an increased risk of arthritis, and no significant differences in average daily gain, BRD relapse, overall mortality, or BRD mortality. There were no significant differences between treatment protocols. Deep nasal swabs (n = 233) taken at arrival (n = 122), treatment (n = 77), and swabs from lungs and joints at postmortem (n = 34) were cultured for Mycoplasma bovis from 61 animals ill or dying of chronic pneumonia and arthritis and from 61 healthy calves. There was significant variation in diversity among isolates (n = 51) between study years and different cattle. Metaphylaxis or antimicrobial treatment did not affect the diversity of isolates. Except for tilmicosin, isolates were largely susceptible to tested antimicrobials.

Effet du traitement antimicrobien et des stratégies préventives sur le complexe respiratoire bovin ainsi que la relation génétique et l'antibiorésistance des isolats deMycoplasma bovisdans un parc d'engraissement de l'Ouest canadien. Les veaux d'un parc d'engraissement (n = 3784) ont été systématiquement randomisés et répartis dans une étude factorielle 2 × 2 pour recevoir de l'oxytétracycline métaphylactique (OTC) à l'arrivée ou pas d'antimicrobien, ainsi qu'une injection sous-cutanée ou deux injections intramusculaires (à intervalle de 48 h) de florfénicol s'ils étaient diagnostiqués avec le complexe respiratoire bovin (CRB). Les veaux de différents groupes de traitement ont été regroupés pêle-mêle et suivis du placement à la réimplantation (~100 jours). Les animaux recevant l'OTC avaient un risque réduit de CRB, un risque accru d'arthrite et ne présentaient pas de différences significatives pour le gain de poids quotidien moyen, la rechute du CRB, la mortalité globale ou la mortalité associée au CRB. Il n'y avait aucune différence significative entre les protocoles de traitement. Des écouvillonnages nasaux profonds (n = 233) prélevés à l'arrivée (n = 122), au traitement (n = 77) et des écouvillonnages des poumons et des articulations post mortem (n = 34) ont été cultivés pour Mycoplasma bovis à partir de 61 animaux malades ou mourants de pneumonie chronique et d'arthrite et de 61 veaux en santé. Il n'y avait aucune variation significative dans la diversité des isolats (n = 51) entre les années d'étude et les différents bovins. La métaphylaxie ou le traitement antimicrobien n'a pas affecté la diversité des isolats. Sauf pour la tilmicosine, les isolats étaient largement sensibles aux antimicrobiens testés.(Traduit par Isabelle Vallières).

Risk factors for herds to test positive for Mycobacterium avium ssp. paratuberculosis-antibodies with a commercial milk enzyme-linked immunosorbent assay (ELISA) in Ontario and western Canada.

The objectives of this study were to identify risk factors associated with i) a Mycobacterium avium subsp. paratuberculosis (MAP)-antibody milk enzyme-linked immunosorbent assay (MAP milk ELISA)-positive herd status, and ii) the within-herd MAP milk ELISA-positive prevalence in Canadian dairy herds. This prospective cohort study was conducted between 2005 and 2009 on 226 herds in Ontario and western Canada, which participated in a voluntary risk assessment (RA)-based Johne's disease control program. Two MAP milk ELISA and risk assessments and a previsit survey were available per herd. The overall farm RA scores alone could not be used to predict whether a herd would test positive for MAP antibodies. However, the results of this study indicated that increasing the likelihood of exposing calves to MAP through certain management practices, as assessed with the RA, increased the likelihood of a herd being test-positive for MAP antibodies.The objectives of this study were to identify risk factors associated with i) a Mycobacterium avium subsp. paratuberculosis (MAP)-antibody milk enzyme-linked immunosorbent assay (MAP milk ELISA)-positive herd status, and ii) the within-herd MAP milk ELISA-positive prevalence in Canadian dairy herds. This prospective cohort study was conducted between 2005 and 2009 on 226 herds in Ontario and western Canada, which participated in a voluntary risk assessment (RA)-based Johne's disease control program. Two MAP milk ELISA and risk assessments and a previsit survey were available per herd. The overall farm RA scores alone could not be used to predict whether a herd would test positive for MAP antibodies. However, the results of this study indicated that increasing the likelihood of exposing calves to MAP through certain management practices, as assessed with the RA, increased the likelihood of a herd being test-positive for MAP antibodies.

RésuméFacteurs de risque pour les troupeaux avec des résultats positifs lors d'un test ELISA pour détecter des anticorps enversMycobacterium aviumssp.paratuberculosisdans le lait commercial de l'Ontario et de l'Ouest canadien. Les objectifs de cette étude consistaient à identifier les facteurs de risque associés à i) un statut positif du troupeau détecté lors d'un test ELISA pour les anticorps envers Mycobacterium avium ssp. paratuberculosis (MAP) dans le lait et ii) et la prévalence de tests ELISA positifs pour MAP au sein du troupeau dans les troupeaux laitiers canadiens. Cette étude prospective d'une cohorte a été réalisée entre 2005 et 2009 auprès de 226 troupeaux de l'Ontario et de l'Ouest canadien qui ont participé à un programme de contrôle de la paratuberculose basé sur une évaluation volontaire des risques. Deux tests ELISA pour MAP et évaluations des risques et une enquête préalable à la visite étaient disponibles pour chaque troupeau. Les notes globales de l'évaluation des risques de la ferme n'ont pas pu être utilisées pour prédire si un troupeau obtiendraient des tests positifs pour les anticorps de MAP. Cependant, les résultats de cette étude ont indiqué que l'augmentation de la probabilité d'exposition des veaux à MAP par le biais de certaines pratiques de gestion, telles qu'examinées lors de l'évaluation des risques, amplifiait la probabilité qu'un troupeau obtienne des résultats positifs pour les anticorps envers MAP.(Traduit par Isabelle Vallières).

Sand impactions in a Saskatchewan beef cow-calf herd.

Forty beef cows were reported to show signs of abdominal pain and discomfort over a period of 1 wk. Two of the affected animals died and on postmortem examination were found to be impacted with sand in their abomasum and small intestines. Sand-laden barley silage was found to be the cause of these impactions.

A comparison of florfenicol-flunixin meglumine versus tulathromycin for the treatment of undifferentiated fever in fall-placed feedlot calves.

The purpose of this study was to compare the efficacy of a new combination drug, florfenicol-flunixin meglumine, with tulathromycin for initial treatment of undifferentiated fever (UF) in fall-placed calves that received metaphylactic tilmicosin on arrival at the feedlot. No significant differences were observed in UF relapses between the two drugs. Calves treated with florfenicol-flunixin had a lower crude case fatality rate (P = .0447) than calves treated with tulathromycin but did not have a significantly lower respiratory disease and histophilosis case fatality rate (P = .12). Whether the new florfenicol-flunixin product is more cost-effective than tulathromycin for the treatment of UF in fall-placed feedlot calves will depend on how the new product is priced in the marketplace relative to tulathromycin.

The behavioral assessment and alleviation of pain associated with castration in beef calves treated with flunixin meglumine and caudal lidocaine epidural anesthesia with epinephrine.

The objectives of this study were 1) to determine the effects of flunixin megulmine in combination with caudal epidural anesthesia as a postoperative analgesic in beef calves following surgical castration, and 2) to consider stride length and pedometry as potential behavioral assessment tools for detecting postcastration pain. Surgical castration was performed in 101 beef calves randomly assigned to 3 treatment subgroups: 1) castration without anesthesia (SURG); 2) castration following lidocaine with epinephrine caudal epidural anesthesia (SURG + EPI); 3) castration following lidocaine with epinephrine caudal epidural anesthesia and flunixin meglumine (SURG + EPI + F). Several outcomes, including pedometer counts, changes in stride length, subjective visual assessment of pain, instantaneous scan sampling of the calves' postoperative activities, and the amount of movement and vocalization during the castration procedure, were measured to identify and quantify pain. The results indicated that stride length and the number of steps taken by calves after castration appear to be good measures of pain. Significant differences found between treatment groups for stride length and visual assessments suggest that flunixin meglumine can be considered to provide visible pain relief up to 8 hours postcastration.

Fibrotic lesions in the testis of bulls and relationship to semen quality.

Ultrasonography of the testes was done in bulls at three locations in western Canada (n=325) and one in Argentina (n=387) to determine the prevalence of fibrotic lesions and to examine the relationship between fibrotic lesions and location, age, breed, right compared with left testes, testis size and semen quality. Fibrotic lesions were common in the testes of bulls raised under intensive rearing conditions in western Canada as well as in the more extensive rearing conditions of Argentina. Fibrotic lesions appeared as early as 5-6 months of age and the number of cases continued to increase until at least 12-14 months of age. The severity of lesions increased in some cases during this period; however, it appears that the development of lesions occurred during a finite period of pubertal development. It is unlikely that the prevalence of lesions is influenced by breed, right compared with left testes or testis size. The cause of the lesions is unknown, but there was an association between the development of fibrotic lesions and an outbreak of BRSV disease in Argentina in one group of bulls. There was some indication that during the active process that leads to fibrosis spermatogenesis is adversely affected; however, the presence of a large number of fibrotic lesions that may occupy as much as 50% of the testis parenchyma did not preclude the production of a greater percentage of sperm with normal morphology.

Biomechanical comparison of six suture configurations using a large diameter polyester prosthesis in the muscular process of the equine arytenoid cartilage.

OBJECTIVE: To compare biomechanical properties of 6 suture configurations using a large diameter polyester prosthesis in the muscular process (MP) of the arytenoid cartilage and to determine failure mode. STUDY DESIGN: Experimental study. SAMPLE POPULATION: Cadaveric equine larynges (n=121). METHODS: Suture configurations (4 single, 2 double) were inserted, and then constructs were tested in a single-cycle to failure at a 100 mm/min distraction. Load deformation curves were generated to assess the biomechanical properties of each construct. A 1-way ANOVA was used to compare the mean differences in construct failure force, cricoarytenoid joint (CAJ) disarticulation force, and energy stored at failure. A 2-sample t-test was used to compare single versus double suture patterns and a Fisher's exact test was used to compare failure mode. RESULTS: Both construct and CAJ failure force were significantly greater (P<.05) for double suture patterns compared with single suture patterns; however, there were no significant differences in energy stored at construct failure. Failure at the MP accounted for >or=50% of construct failures for 3 of the single suture patterns and 1 of the double suture patterns tested. The remaining 2 patterns had an increased frequency of clamp failures as well as failure of the cricoid cartilage. CONCLUSIONS: Sutures that sufficiently engage the spine of the MP alone or in conjunction with a second suture were found to be biomechanically superior. CLINICAL RELEVANCE: Engaging the spine of the MP appears to result in the most biomechanically sound laryngeal construct.

Comparison of florfenicol and tulathromycin for the treatment of undifferentiated fever in Alberta feedlot calves.

The purpose of this study was to compare the efficacy and cost-effectiveness of florfenicol versus tulathromycin for initial treatment of undifferentiated fever in fall-placed steer calves that received metaphylactic tilmicosin on arrival at the feedlot. No significant differences (P > .10) were observed in undifferentiated fever relapses or the crude case fatality rate. Calves treated with florfenicol had a lower case fatality rate (P = .04) for bovine respiratory disease and Histophilus disease than did calves treated with tulathromycin. The net economic advantage of florfenicol over tulathromycin (Can$17.70/treated animal) was based on differences in costs for the trial drug and calf replacement owing to bovine respiratory disease and Histophilus disease case fatality.

Comparative efficacy of tilmicosin versus tulathromycin as a metaphylactic antimicrobial in feedlot calves at moderate risk for respiratory disease.

The purpose of this study was to compare the efficacy and cost-effectiveness of tilmicosin (MIC) versus tulathromycin (DRAX) as a metaphylactic antimicrobial in feedlot calves at moderate risk for bovine respiratory disease (BRD). Calves that received DRAX had significantly (P < or = .05) lower initial BRD treatment rates compared with calves that received MIC. However, there were no significant differences in the BRD relapse rate, railer rate, total mortality rate, BRD mortality rate, average daily gain, and dry matter conversion between the two groups. The economic advantage of the MIC group was Can$8.29/animal. Based on these results, while DRAX was more efficacious in reducing initial treatments for BRD in feedlot calves at moderate risk for disease, MIC was more cost-effective. The lower initial BRD treatment costs in the DRAX group did not offset the higher metaphylactic cost of DRAX.

Open versus laparoscopic Roux-en-Y gastric bypass: a comparative study of over 25,000 open cases and the major laparoscopic bariatric reported series.

BACKGROUND: Laparoscopic bariatric surgery has experienced a rapid expansion of interest over the past 5 years, with a 470% increase. This rapid expansion has markedly increased overall cost, reducing surgical access. Many surgeons believe that the traditional open approach is a cheaper, safer, equally effective alternative. METHODS: 16 highly experienced "open" bariatric surgeons with a combined total of 25,759 cases representing >200 surgeon years of experience, pooled their open Roux-en-Y gastric bypass (ORYGBP) data, and compared their results to the leading laparoscopic (LRYGBP) papers in the literature. RESULTS: In the overall series, the incisional hernia rate was 6.4% using the standard midline incision. Utilizing the left subcostal incision (LSI), it was only 0.3%. Return to surgery in <30 days was 0.7%, deaths 0.25%, and leaks 0.4%. Average length of stay was 3.4 days, and return to usual activity 21 days. Small bowel obstruction was significantly higher with the LRYGBP. Surgical equipment costs averaged approximately $3,000 less for "open" cases. LRYGBP had an added expense for longer operative time. This more than made up for the shorter length of stay with the laparoscopic approach. CONCLUSIONS: The higher cost, higher leak rate, higher rate of small bowel obstruction, and similar long-term weight loss results make the "open" RYGBP our preferred operation. If the incision is taken out of the equation (i.e. use of the LSI), the significant advantages of the open technique become even more obvious.

Monensin might protect Ontario, Canada dairy cows from paratuberculosis milk-ELISA positivity.

Our objective was to define the role of monensin sodium in protecting cows from being milk-ELISA positive for paratuberculosis in Ontario, Canada dairy herds. In total, 4933 dairy cows from 94 herds were enrolled in this cross-sectional study. Forty-four of the enrolled herds were selected purposively by their herd veterinarian and another 50 herds were randomly selected from a local milk production-recording agency. A herd-management survey was completed on each farm during the months of May through August 2003. During this same time-period, composite milk samples were collected from all lactating cows and tested with a milk-ELISA for antibodies to Mycobacterium avium subspecies paratuberculosis. Analyses were stratified according to the paratuberculosis history of the herds. In the 48 herds in which paratuberculosis had not been diagnosed before, the use of calf hutches and monensin in milking cows were both associated with reduced odds of a cow testing positive (OR=0.19 and 0.21, respectively). In the 46 herds with a prior history of paratuberculosis, feeding monensin to the breeding-age heifers was associated with decreased odds of a cow testing positive (OR=0.54). Monensin use might be associated with milk-ELISA positivity, but its impact on the transmission of paratuberculosis remains unknown.

Efficacy of monensin sodium for the reduction of fecal shedding of Mycobacterium avium subsp. paratuberculosis in infected dairy cattle.

Reducing the quantity of Mycobacterium avium subsp. paratuberculosis (MAP) being shed by cows with Johne's disease should decrease the risk of spread of this disease to young stock. Previous work has suggested that monensin sodium decreases the pathologic lesions associated with Johne's disease, but the impact on shedding of viable MAP remains unknown. After serologic screening of 32 dairy herds in southwestern Ontario, 228 cows from 13 of these herds were enrolled into a randomized clinical trial. Fecal culture and PCR were used to identify 114 cows as potential fecal shedders, while another 114 cows were enrolled as ELISA negative, herd and parity matched controls. All cows were randomized to receive either a monensin controlled release capsule (CRC) or a placebo capsule. Serial fecal and blood samples were collected for fecal culture and serum ELISA testing over a 98-day period. On day 98 of the study, treatments were switched for all cows continuing in the trial. These remaining cows were followed for another 98 days with a similar sampling protocol. Mixed effect models were used to measure the impact of treatment on the number of colony forming units identified on fecal cultures over time. During the first 98 days of the study, cows treated with a monensin CRC were found to shed 3.4cfu per tube less than placebo treated cows (P=0.05). The serum ELISA S/P ratio was reduced by 1.39 units in cows given monensin (P=0.06). However, treatment with monensin did not reduce the odds of testing positive on serology. Only the cows shedding MAP on day 0 were found to have a reduced odds of testing positive on fecal culture when treated with monensin (OR=0.27; P=0.03). Monensin sodium administered to infected animals at 335mg/day marginally reduced fecal shedding of MAP in mature dairy cattle, but the biological significance of this reduction is unknown.

Effect of sample pooling and transport conditions on the clinical sensitivity of a real-time polymerase chain reaction assay for Campylobacter fetus subsp. venerealis in preputial samples from bulls.

The diagnosis of bovine genital campylobacteriosis (BGC) presents significant challenges, as traditional methods lack sensitivity when prolonged transport of samples is required. Assays of preputial samples by means of real-time polymerase chain reaction (PCR) provide good sensitivity and high throughput capabilities. However, there is limited information on the acceptable duration of transport and temperature during transport of samples. In addition, the use of pooled samples has proven to be a valuable strategy for the diagnosis of other venereal diseases in cattle. The objectives of the present study were to determine the effect of sample pooling and of transport time and temperature on the clinical sensitivity of a real-time quantitative PCR (qPCR) assay for Campylobacter fetus subsp. venerealis in preputial samples from beef bulls. Eight infected bulls and 176 virgin yearling bulls were used as the source of samples. The qPCR sensitivity was comparable for unpooled samples and pools of 5 samples, whereas sensitivity was decreased for pools of 10 samples. Sensitivity for the various pool sizes improved with repeated sampling. For shorter-term transport (2 and 48 h), sensitivity was greatest when the samples were stored at 4°C and 30°C, whereas for longer-term transport (96 h) sensitivity was greatest when the samples were stored at -20°C. The creation of pools of 5 samples is therefore a good option to decrease costs when screening bulls for BGC with the qPCR assay of direct preputial samples. Ideally the samples should be stored at 4°C and arrive at the laboratory within 48 h of collection, but when that is not possible freezing at -20°C could minimize the loss of sensitivity.

Le diagnostic de la campylobactériose génitale bovine (CGB) présente des défis significatifs, étant donné que les méthodes traditionnelles manquent de sensibilité lorsqu'un transport prolongé des échantillons est requis. Les épreuves utilisant des échantillons prépuciaux dans des épreuves de réaction d'amplification en chaine par la polymérase en temps réel (PCR) ont une bonne sensibilité et une capacité de rendement élevée. Toutefois, il y a peu d'information sur la durée acceptable du transport et de la température durant le transport des échantillons. De plus, l'utilisation d'échantillons regroupés s'est avéré être une stratégie valable pour le diagnostic d'autres maladies vénériennes chez les bovins. Les objectifs de la présente étude étaient de déterminer l'effet du regroupement d'échantillons et du temps de transport et de la température sur la sensibilité clinique d'une épreuve PCR quantitative en temps réel (qPCR) pour Campylobacter fetus ssp. venerealis dans des échantillons prépuciaux provenant de taureaux. Huit taureaux infectés et 176 bouvillons vierges ont été utilisés comme source des échantillons. La sensibilité du qPCR était comparable pour des échantillons non-regroupés et des regroupements de 5 échantillons, mais diminuée pour des regroupements de 10 échantillons. La sensibilité pour les différentes tailles de regroupement s'améliorait suite à des échantillonnages répétés. Pour des transport de courte durée (2 et 48 h), la sensibilité était plus élevée lorsque les échantillons étaient entreposés à 4 °C et 30 °C, alors que pour le transport de longue durée (96 h) la sensibilité était plus élevée lorsque les échantillons étaient entreposés à −20 °C. La création de regroupement de 5 échantillons est une bonne option pour diminuer les coûts lors du tamisage de taureaux pour CGB avec le qPCR effectué directement sur des échantillons prépuciaux. Idéalement, les échantillons devraient être entreposés à 4 °C et arriver au laboratoire au plus tard 48 h après le prélèvement, si ce n'est pas possible, la congélation à −20 °C pourrait minimiser la perte de sensibilité.(Traduit par Docteur Serge Messier).

Evaluation of enzyme-linked immunosorbent assays performed on milk and serum samples for detection of paratuberculosis in lactating dairy cows.

OBJECTIVE: To determine whether results obtained for milk and serum samples with ELISAs intended for diagnosis of paratuberculosis in dairy cows were comparable to results obtained by means of mycobacterial culture of fecal samples. DESIGN: Cross-sectional study. ANIMALS: 689 lactating dairy cows in 9 Ontario herds. PROCEDURE: Milk, serum, and fecal samples were obtained from all cows. Fecal samples were submitted for mycobacterial culture. Serum samples were tested with a commercially available ELISA for antibodies against Mycobacterium paratuberculosis, and preserved milk samples were tested with an indirect ELISA for antibodies against M paratuberculosis. RESULTS: Results were positive for 130 of the 689 (18.9%) serum samples, 77 of the 689 (11.1%) milk samples, and 72 of the 689 (10.4%) fecal samples. The level of agreement between results for milk and serum samples was only moderate. Proportions of positive results for serum and fecal samples were significantly different, but proportions of positive results for milk and fecal samples were not significantly different. In addition, results for milk samples had a higher level of agreement with results of mycobacterial culture than did results for serum samples. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that the indirect ELISA used on milk samples may be a convenient method of detecting paratuberculosis in dairy herds.

Effect of paratuberculosis on culling, milk production, and milk quality in dairy herds.

OBJECTIVE: To determine the effect of paratuberculosis on culling, milk production, and milk quality in infected dairy herds. DESIGN: Cross-sectional study. ANIMALS: 689 lactating dairy cows in 9 herds. PROCEDURE: Milk, blood, and fecal samples were obtained from all cows. Fecal samples were evaluated via mycobacterial culture. Serum samples were tested with a commercially available ELISA for antibodies against Mycobacterium avium subsp paratuberculosis, and preserved milk samples were tested with an ELISA for antibodies against M paratuberculosis. Mixed effect and proportional hazards models were used to determine the effect of paratuberculosis on 305-day milk, fat, and protein production; somatic cell count linear score; and the risk of culling. RESULTS: Cows with positive results of bacteriologic culture of feces and milk ELISA produced less milk, fat, and protein, compared with herdmates with negative results. No difference in 305-day milk or fat production was detected in cows with positive results of serum ELISA, compared with seronegative cows. The 3 survival analyses revealed that cows with positive results of each test were at higher risk of being culled than cows with negative results. Paratuberculosis status, as determined by use of all 3 diagnostic tests, was not associated with milk somatic cell count linear score. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that for the 9 herds in this study, paratuberculosis significantly decreased milk production and cow longevity.

The prevalence of milk and serum antibodies to Mycobacterium avium subspecies paratuberculosis in dairy herds in Ontario.

This study randomly surveyed 50 dairy herds in Ontario; 18% and 30% of herds had 2 or more milk or serum enzyme-linked immunosorbent assay (ELISA)-positive cows, respectively. The apparent cow level prevalence was 1.7% and 2.6% on the milk and serum ELISA, respectively. The serum and milk assays agreed moderately.