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Many issues concerning the taxonomy of Echinococcus have been resolved in recent years with the application of molecular tools. However, the status of Echinococcus maintained in transmission cycles involving cervid intermediate hosts remains to be determined. The recent characterization of the parasite from cervids in Finland has highlighted the paucity of data available, particularly that from North America. In this study, we have characterized a large number of Echinococcus isolates from cervids from Western Canada on the basis of morphology and molecular genetic techniques. Our results support earlier studies suggesting that Echinococcus of cervid origin is phenotypically and genetically distinct to Echinococcus maintained in domestic host assemblages, and also confirms that Echinococcus of cervid origin does not constitute a genetically homogeneous group. However, our data do not support the existence of 2 distinct genotypes (strains/ subspecies) with separate geographical distributions. Our data appear to support the existence of only 1 species in cervids, but additional isolates from cervids and wolves in other endemic regions should be characterized before a final decision is made on the taxonomic status of Echinococcus in cervids.

BackgroundCastration is one of the most common procedures performed on beef and dairy cattle. The objective of the study was to determine the efficacy of meloxicam oral suspension in reducing pain and inflammation in calves following band or surgical castration.MethodsTwo identical trials with the exception of the method of castration (Band Castration Study 1 and Surgical Castration Study 2) were conducted. Sixty (60) healthy Holstein calves 4 to 5 months of age (138–202 Kg) were used. Animals received either Meloxicam Oral Suspension at a dose of 1 mg/kg BW (n = 15 Study 1 and 15 Study 2) or Saline (n = 15 Study 1 and 15 Study 2) 2 h before castration. Physiological (Heart Rate, Plasma Cortisol and Plasma Substance P) and Behavioral (Visual Analog Scale (VAS), Accelerometers and tail Pedometers) evaluations were conducted before (day -1) and after Castration (Day 0, 1, 2, 3). Inflammation was evaluated daily by providing an individual animal score (Study1) or with a measurement of scrotal thickness (Study 2).ResultsHeart rates were significantly greater in control animals following band and surgical castration. Plasma cortisol and substance P were significantly reduced in animals receiving Meloxicam Oral Suspension. Control animals had significantly greater VAS scores. Accelerometers showed that meloxicam treated animals had a significantly greater motion index and number of steps as well as less % time lying and number of lying bouts. The scrotal inflammation (based on scrotal swelling) was significantly decreased in the meloxicam treated animals compared to the control animals on day 1, day 2 and 3.ConclusionMeloxicam Oral Suspension was able to significantly reduce the display of painful behaviors and physiological responses to pain in band castrated and surgical castrated calves for up to 72 h following a single oral treatment of 1 mg/kg body weight. Meloxicam Oral Suspension was able to significantly reduce scrotal inflammation in band castrated and surgical castrated calves.

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Bovine respiratory disease (BRD) is the most important illness of feedlot cattle. Disease management targets the associated bacterial pathogens, Mannheimia haemolytica, Mycoplasma bovis, Pasteurella multocida, Histophilus somni, and Trueperella pyogenes. We conducted a cross-sectional study to measure the frequencies of antimicrobial-resistant BRD pathogens using a collaborative network of veterinarians, industry, government, and a diagnostic laboratory. Seven private veterinary practices in southern Alberta collected samples from both living and dead BRD-affected animals at commercial feedlots. Susceptibility testing of 745 isolates showed that 100% of the M. haemolytica, M. bovis, P. multocida, and T. pyogenes isolates and 66.7% of the H. somni isolates were resistant to at least one antimicrobial class. Resistance to macrolide antimicrobials (90.2% of all isolates) was notable for their importance to beef production and human medicine. Multidrug resistance (MDR) was high in all target pathogens with 47.2% of the isolates resistant to four or five antimicrobial classes and 24.0% resistance to six to nine classes. We compared the MDR profiles of isolates from two feedlots serviced by different veterinary practices. Differences in the average number of resistant classes were found for M. haemolytica (p < 0.001) and P. multocida (p = 0.002). Compared to previous studies, this study suggests an increasing trend of resistance in BRD pathogens against the antimicrobials used to manage the disease in Alberta. For the veterinary clinician, the results emphasize the importance of ongoing susceptibility testing of BRD pathogens to inform treatment protocols. Surveillance studies that collect additional epidemiological information and manage sampling bias will be necessary to develop strategies to limit the spread of resistance.

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Over a two-year period, Mannheimia haemolytica (MH; n = 113), Pasteurella multocida (PM; n = 47), Histophilus somni (HS; n = 41) and Mycoplasma bovis (MB; n = 227) were isolated from bovine lung tissue at necropsy from cattle raised conventionally (CON, n = 29 feedlots) or without antimicrobials [natural (NAT), n = 2 feedlots]. Excluding MB, isolates were assayed by PCR to detect the presence of 13 antimicrobial resistance (AMR) genes and five core genes associated with integrative and conjugative elements (ICEs). Antimicrobial susceptibility phenotypes and minimum inhibitory concentrations (MICs, µg/mL) were determined for a subset of isolates (MH, n = 104; PM, n = 45; HS, n = 23; and MB, n = 61) using Sensititre analyses. A subset of isolates (n = 21) was also evaluated by whole-genome sequencing (WGS) based on variation in AMR phenotype. All five ICE core genes were detected in PM and HS by PCR, but only 3/5 were present in MH. Presence of mco and tnpA ICE core genes in MH was associated with higher MICs (p < 0.05) for all tetracyclines, and 2/3 of all macrolides, aminoglycosides and fluoroquinolones evaluated. In contrast, association of ICE core genes with MICs was largely restricted to macrolides for PM and to individual tetracyclines and macrolides for HS. For MH, the average number of AMR genes markedly increased (p < 0.05) in year 2 of the study due to the emergence of a strain that was PCR positive for all 13 PCR-tested AMR genes as well as two additional AMR genes (aadA31 and blaROB-1) detected by WGS. Conventional management of cattle increased (p < 0.05) MICs of tilmicosin and tulathromycin for MH; neomycin and spectinomycin for PM; and gamithromycin and tulathromycin for MB. The average number of PCR-detected AMR genes in PM was also increased (p < 0.05) in CON mortalities. This study demonstrates increased AMR especially to macrolides by bovine respiratory disease organisms in CON as compared to NAT feedlots and a rapid increase in AMR following dissemination of strain(s) carrying ICE-associated multidrug resistance.

. 2000. Individual intake of mineral and molasses supplements by cows, heifers and calves. Can. J. Anim. Sci. 80: 681-690. In two pastures, two multiplex radio frequency (RF) mineral feeders (GrowSafe Systems Ltd.) equipped with load cells were used to monitor feeder attendance and individual intake of mineral by 33 and 36 cow-calf pairs individually identified by RF transponders. A visit was defined as a return to the feeder after a 5-min absence. In exp. 1, attendance of cows and calves at the feeder and intake of mineral were monitored over 13 d. Sodium chloride was included in the mineral at 9.8% (low salt, LS) on days 1 to 6, and at 22.5% (high salt, HS) on days 7 to 13. Percentages of cows and calves that visited the feeder were similar between LS (60.9% and 21.7% respectively) and HS (62.3% and 24.6%). Number of visits (P > 0.05) and daily mineral intake (P < 0.1) were reduced in cows fed HS as compared with LS. Cows had more visits (P < 0.001) and consumed more mineral (P < 0.001) than did calves. In exp. 2, HS as is (control, C) or formulated to contain 0.468% fenbendazole (FB) was provided for 6 d to 36 and 32 cow-calf pairs in adjacent pastures. All of the cows and 93.8% of the calves attended the FB feeder, whereas only 77.8% of the cows and 33.3% of the calves attended the feeder containing C. Fenbendazole increased visits per day (P < 0.05) by both cows and calves. Intakes of FB and C did not differ, but cows consumed more (P < 0.001) mineral than did calves. In exp. 3, variability in intake of proteinmolasses blocks by cows and heifers was examined. Intake differed by animal (P < 0.01), but was similar between cows and heifers. Individual average intake was 445 g d -1 with a range of 0 to 1650 g d -1 . These experiments demonstrate that universal and uniform consumption of an additive in mineral or molasses supplements by individuals in a herd cannot be assumed. To whom correspondence should be addressed (e-mail: mcallister@em.agr.ca) Abbreviations: ADF, acid detergent fibre; BW, body weight; C, mineral mix containing no fenbendazole (control); CP, crude protein; FB, mineral mix containing 0.486% fenbendazole; HS, mineral mix containing 22.5% sodium chloride (high salt); LS, mineral mix containing 9.8% sodium chloride (low salt); RF, radio frequency Can. J. Anim. Sci. Downloaded from www.nrcresearchpress.com by 18.236.198.91 on 05/09/18For personal use only.