Serological evidence for historical and present-day exposure of North American bison to Mycoplasma bovis.

BACKGROUND: Mycoplasma bovis causes mastitis, otitis, pneumonia and arthritis in cattle and is a major contributor to bovine respiratory disease complex. Around the year 2000, it emerged as a significant threat to the health of North American bison. Whether healthy bison are carriers of M. bovis and when they were first exposed is not known. To investigate these questions we used a commercially available ELISA that detects antibodies to M. bovis to test 3295 sera collected from 1984 through 2019 from bison in the United States and Canada. RESULTS: We identified moderately to strongly seropositive bison from as long ago as the late 1980s. Average seroprevalence over the past 36 years is similar in the United States and Canada, but country-specific differences are evident when data are sorted by the era of collection. Seroprevalence in the United States during the pre-disease era (1999 and prior) was significantly higher than in Canada, but was significantly lower than in Canada during the years 2000-2019. Considering individual countries, seroprevalence in the United States since the year 2000 dropped significantly as compared to the years 1985-1999. In Canada the trend is reversed, with seroprevalence increasing significantly since the year 2000. ELISA scores for sera collected from free-ranging bison do not differ significantly from scores for sera from more intensively managed animals, regardless of the era in which they were collected. However, seroprevalence among intensively raised Canadian bison has nearly doubled since the year 2000 and average ELISA scores rose significantly. CONCLUSIONS: Our data provide the first evidence that North American bison were exposed to M. bovis many years prior to the emergence of M. bovis-related disease. Patterns of exposure inferred from these results differ in the United States and Canada, depending on the era under consideration. Our data further suggest that M. bovis may colonize healthy bison at a level sufficient to trigger antibody responses but without causing overt disease. These findings provide novel insights as to the history of M. bovis in bison and will be of value in formulating strategies to minimize the impact of mycoplasmosis on bison health and production.

Evaluation of intramuscular sodium nitroprusside injection to improve oxygenation in white-tailed deer (Odocoileus virginianus) anesthetized with medetomidine-alfaxalone-azaperone.

OBJECTIVE: In ungulates, α2-adrenergic agonists can decrease oxygenation possibly through alteration of pulmonary perfusion. Sodium nitroprusside can decrease pulmonary vascular resistance (PVR) and increase cardiac output (Q˙t) through vasodilation. The objective was to determine if sodium nitroprusside would improve pulmonary perfusion and attenuate the increased alveolar-arterial (a-a) gradient resulting from medetomidine-azaperone-alfaxalone (MAA) administration. STUDY DESIGN: Prospective, randomized, crossover study with a 2 week rest period. ANIMALS: A group of eight adult female captive white-tailed deer (Odocoileus virginianus). METHODS: Deer were administered MAA intramuscularly (IM), and auricular artery and pulmonary artery balloon catheters were placed. Deer spontaneously breathed air. Saline or sodium nitroprusside (0.07 mg kg-1) were administered IM 40 minutes after MAA injection. Heart rate (HR), mean arterial pressure (MAP), mean pulmonary arterial pressure (MPAP), pulmonary artery occlusion pressure (PAOP), right atrial pressure (RAP), Q˙t, arterial pH, PaCO2 and PaO2 were obtained immediately before nitroprusside injection (baseline) and 5, 10 and 15 minutes afterwards. Mixed venous blood samples were obtained at baseline and at 5 minutes. Systemic vascular resistance (SVR), PVR, intrapulmonary shunt fraction (Q˙s/Q˙t), a-a gradient, oxygen delivery (D˙O2) and oxygen extraction ratio (O2ER) were calculated. Statistical analysis was performed with repeated measures analysis of variance with correction factors. A p value < 0.05 was considered significant. RESULTS: With nitroprusside, MAP, MPAP, PAOP, RAP, SVR and O2ER significantly decreased and HR, Q˙t and D˙O2 increased compared with baseline and between treatments. There was a significant decrease in PVR and a-a gradient and increase in PaO2 compared with baseline and saline treatment. Changes were not sustained. CONCLUSIONS AND CLINICAL RELEVANCE: Nitroprusside temporarily changed hemodynamic variables, increased PaO2 and decreased a-a gradient. Nitroprusside possibly led to better pulmonary perfusion of ventilated alveoli. However, IM nitroprusside at this dose is not recommended because of severe systemic hypotension and short action.

Pharmacokinetics of imidocarb dipropionate in white-tailed deer (Odocoileus virginianus) after single intramuscular administration.

This study was designed to investigate the pharmacokinetics of imidocarb, a carbanilide derivative, in white-tailed deer (Odocoileus virginianus). The pharmacokinetic properties of a single intramuscular (IM) dose of imidocarb were determined in 10 deer. A single IM injection of 3.0 mg/kg imidocarb dipropionate was administered, and blood samples were collected prior to, and up to 48 hr after imidocarb administration. Plasma imidocarb concentrations were determined by high-performance liquid chromatography with ultraviolet detection. The disposition of plasma imidocarb was best characterized by a two-compartment open model. The mean ± SE maximal imidocarb concentration in deer was 880.78 ± 81.12 ng/ml at 38.63 ± 5.30 min postinjection. The distribution phase had a half-life (t1/2α ) of 25.90 ± 10.21 min, and plasma imidocarb concentration declined with a terminal elimination half-life (t1/2ß ) of 464.06 ± 104.08 min (7.73 ± 1.73 hr). Apparent volume of distribution based on the terminal phase (VZ /F) was 9.20 ± 2.70 L/kg, and apparent total body clearance (Cl/F) was 15.97 ± 1.28 ml min-1  kg-1 .

An observational study of mortality on bison farms in Saskatchewan with special emphasis on malignant catarrhal fever.

In December 2011, the Malignant Catarrhal Fever (MCF) Task Force in Saskatchewan recommended that research be conducted on the relationship between the proximity of bison and sheep under typical commercial production settings and bison deaths due to MCF. The objective of this study was to evaluate all causes of death in bison herds and compare the incidence of MCF in herds at varying distances of exposure from sheep operations. Necropsies were completed on 76 of 133 bison reported to have died during the 18-month study period. A total of 7 MCF deaths was reported from 2 large herds within 1.0 km of sheep operations. Although there was a greater risk of MCF deaths in bison herds within 1.0 km of sheep operations than in herds more than 1.0 km away, the overall incidence of MCF deaths within the study period was very low. Most deaths were attributed to non-infectious causes, including copper deficiency.

Étude observationnelle de la mortalité dans des fermes de bisons en Saskatchewan, avec une emphase particulière sur la fièvre catarrhale maligne des bovins. En décembre 2011, le groupe de travail de la Saskatchewan sur la fièvre catarrhale maligne des bovins (FCM) a recommandé la réalisation de travaux de recherche pour étudier le lien entre la proximité des bisons et des moutons dans des milieux de production commerciaux typiques et la mortalité des bisons attribuable à la FCM. La recherche avait pour but d'évaluer toutes les causes de mortalité dans les troupeaux de bisons, puis de comparer l'incidence de la FCM dans les troupeaux à diverses distances d'exposition des exploitations d'élevage de moutons. Des nécropsies ont été réalisées sur 76 des 133 bisons dont la mort a été signalée durant la période d'étude de 18 mois. Un total de sept morts causées par la FCM a été signalé dans deux grands troupeaux situés à une distance de moins de 1 km. Le risque de mortalité pour cause de FCM était supérieur dans les troupeaux de bisons situés à moins de 1 km des exploitations de moutons que dans les troupeaux situés à une distance de plus de 1 km. Cependant, l'incidence totale de mortalité causée par la FCM était très faible. La plupart des mortalités étaient attribuables à des causes non infectieuses, y compris une carence en cuivre.(Traduit par Isabelle Vallières).

Septicemic pasteurellosis in farmed elk (Cervus canadensis) in Alberta.

Septicemic pasteurellosis is a bacterial disease of domestic and wild animals including bison, elk, and pronghorn antelope caused by Pasteurella multocida. Here we report 2 cases of septicemic pasteurellosis in farmed elk. Pasteurella multocida serogroup B was isolated from multiple tissues in both animals. Gene sequencing (16S ribosomal RNA) and BLAST query confirmed that the sequence is 99% to 100% homologous to the P. multocida sequences in the database.

Pasteurellose septicémique chez des wapitis d'élevage(Cervus canadensis)en Alberta. La pasteurellose septicémique est une maladie bactérienne des animaux domestiques et sauvages, dont le bison, le wapiti et l'antilocarpe, qui est causée par Pasteurella multocida. Dans le présent article, nous présentons un rapport sur 2 cas de pasteurellose septicémique chez les wapitis d'élevage. Le sérogroupe B de Pasteurella multocida a été isolé dans des plusieurs tissus des deux animaux. Le séquençage des gènes (ARN ribosomique16S) et une recherche BLAST a confirmé que la séquence est de 99 % à 100 % homologue aux séquences de P. multocida dans la base de données.(Traduit par Isabelle Vallières).

EFFICACY AND SAFETY OF A MEDETOMIDINE-AZAPERONE-ALFAXALONE COMBINATION IN CAPTIVE WHITE-TAILED DEER (ODOCOILEUS VIRGINIANUS).

Alfaxalone is a neurosteroid that interacts with gamma-aminobutyric type A receptors to produce central nervous system depression and muscle relaxation. The effects of alfaxalone vary from sedation to general anesthesia. Alfaxalone is synergistic with other tranquilizers and sedatives and therefore has the potential to improve existing alpha-2 adrenergic agonist-based combinations used for wildlife immobilization. The objective of this study was to determine the efficacy and cardiopulmonary effects of a medetomidine-azaperone-alfaxalone (MAA) combination in captive white-tailed deer (Odocoileus virginianus). Eight captive white-tailed deer were restrained in a drop-floor chute; hand injected i.m. with 0.15 mg/kg medetomidine, 0.2 mg/kg azaperone, and 0.5 mg/kg alfaxalone; and released into a small enclosure for observation. The deer were maintained in lateral recumbency for a total time from postinjection (PI) of the drug of 60 min. At 60 min PI, atipamezole was administered i.m. at five times the medetomidine dose. Heart rate, respiratory rate, rectal temperature, and direct systolic, mean, and diastolic arterial blood pressures were recorded every 5 min. Arterial blood samples were taken every 15 min for blood gas analysis. Level of sedation and quality of recovery were scored. Statistical analysis was performed using analysis of variance and descriptive statistics with a significance level of P < 0.05. Induction (time to lateral recumbency, 7.1 ± 2.4 min (mean ± SD) and recovery times (time to standing, 9.1 ± 3.1 min) were comparable to currently used medetomidine-based combinations in white-tailed deer. Major cardiopulmonary effects observed (values reported are 15 min PI of immobilizing drugs) were hypoxemia (PaO2, 54 ± 9 mm Hg), hypoventilation (PaCO2, 55 ± 3 mm Hg), and mixed acid-base disturbances (pH, 7.22 ± 0.04). No adverse effects were observed after recovery from anesthesia. MAA produced a satisfactory level of deep sedation for safe handling and minor procedures in captive white-tailed deer.

Ovarian synchronisation in wood bison (Bison bison athabascae) during the anovulatory season.

Two experiments were performed in wood bison during the anovulatory season to establish an effective protocol for ovarian synchronisation. In an untreated control phase, bison cows (n=19) were examined daily to establish the interval to new follicular wave emergence (4.9±0.7 days) for the purposes of comparison with the experimental treatments. In Experiment 1, bison were treated by transvaginal ultrasound-guided follicular ablation (n=9) or with 2mg, i.m., 17ß-oestradiol (n=10). In Experiment 2, bison were treated by follicular ablation (n=9) or with 2mg, i.m., 17ß-oestradiol +100mg, i.m., progesterone (n=10). In Experiment 1, the interval to new wave emergence for control, follicular ablation and 17ß-oestradiol-treated groups was 4.9±0.7, 1.1±0.1 and 3.1±0.4 days, respectively (P<0.05). The degree of synchrony was 2.4±0.4, 0.2±0.1 and 0.8±0.2 days, respectively (P<0.05). In Experiment 2, the interval to new wave emergence for control, follicular ablation and 17ß-oestradiol + progesterone-treated groups was 4.9±0.7, 1.2±0.2 and 3.3±0.3 days, respectively (P<0.05), and the degree of synchrony was 2.4±0.4, 0.2±0.1, and 0.8±0.2 days, respectively (P<0.05). The degree of synchrony did not differ between ablation and hormone treatment groups in either experiment, but was greater in treatment groups than in the untreated control phase. Both follicular ablation and hormone treatment shortened and decreased the variability in the interval to follicular wave emergence in bison, but wave emergence occurred earlier after follicular ablation.

A survey to detect Toxocara vitulorum and other gastrointestinal parasites in bison (Bison bison) herds from Manitoba and Saskatchewan.

An egg count survey using environmental fecal samples obtained in spring or early summer was conducted to estimate the apparent prevalence of Toxocara vitulorum in unweaned bison calves and of other intestinal parasites in adult bison on 98 farms in Manitoba and Saskatchewan. Calf samples were pooled (maximum 5 samples per pool) by farm and positive pools were examined to determine individual T. vitulorum counts. Toxocara vitulorum eggs were found on 4 farms in Manitoba and none in Saskatchewan. Apparent herd-level prevalence estimates were 12% [95% confidence interval (95% CI): 3.4% to 28.2%] and 0% (95% CI: 0% to 5.7%) respectively. Samples from adult bison contained eggs/oocysts from trichostrongyle species, Eimeria sp., Monieza sp., Capillaria sp., Nematodirus sp. and Trichuris sp. in 100%, 95%, 72%, 13%, 13%, and 5% of herds, respectively. Strongyloides sp. were not found in any herd. Further studies are needed to assess parasite distribution patterns in bison and to evaluate the risk that T. vitulorum may pose to bison, cattle, and wildlife.

Une enquête pour détecterToxocara vitulorumet d'autres parasites gastro-intestinaux dans des troupeaux de bisons(Bison bison)du Manitoba et de la Saskatchewan. Une enquête sur la numération des œufs à l'aide d'échantillons fécaux environnementaux obtenus au printemps ou au début de l'été a été réalisée afin d'estimer la prévalence apparente de Toxocara vitulorum chez des veaux de bisons non sevrés et d'autres parasites intestinaux chez les bisons adultes dans 98 fermes du Manitoba et de la Saskatchewan. Les échantillons des veaux ont été regroupés (maximum de 5 échantillons par groupe) par ferme et les groupes positifs ont été examinés afin de déterminer les numérations individuelles de T. vitulorum. Des œufs de Toxocara vitulorum ont été trouvés dans 4 fermes au Manitoba et dans aucune ferme en Saskatchewan. Les estimations de prévalence apparentes au niveau du troupeau étaient de 12 % (intervalle de confiance de 95 % [IC de 95 %] : de 3,4 % à 28,2 %) et 0 % (IC de 95 % : de 0 % à 5,7 %) respectivement. Les échantillons des bisons adultes contenaient des œufs/ookystes d'espèces de trichostrongyles, Eimeria sp., Monieza sp., Capillaria sp., Nematodirus sp. et Trichuris sp. dans 100 %, 95 %, 72 %, 13 %, 13 % et 5 % des troupeaux, respectivement. Strongyloides sp. n'a pas été trouvé dans aucun troupeau. De nouvelles études sont requises pour évaluer les tendances de distribution des parasites chez les bisons et le risque que T. vitulorum puisse poser pour les bisons, le bétail et la faune.(Traduit par Isabelle Vallières).

Low flow oxygen therapy from a portable oxygen concentrator or an oxygen cylinder effectively treats hypoxemia in anesthetized white-tailed deer (Odocoileus virginianus).

For treatment of hypoxemia, delivery of the minimum effective oxygen flow rate is advantageous during field anesthesia because it prolongs the life of the oxygen cylinder. Portable oxygen concentrators as the oxygen source require less logistical considerations than cylinders and are a safer alternative during helicopter field work because they are nonexplosive devices. The objective of this study was to evaluate low oxygen flow rates by continuous or pulsed intranasal delivery for treatment of hypoxemia in anesthetized white-tailed deer (Odocoileus virginianus). Nine captive adult female deer (body mass 56-72 kg) were physically restrained in a drop-floor chute and hand injected intramuscularly with medetomidine (0.1-0.14 mg/kg) and ketamine (2.5-4.3 mg/kg). Intranasal oxygen was delivered from an oxygen cylinder at continuous flow rates of 1 and 2 L/min or from a battery driven oxygen concentrator (EverGo Portable Oxygen Concentrator, Respironics) with pulse-dose delivery (maximum capacity of 1.05 L/min). The pulse-dose setting (pulse volume 12-70 ml) was adjusted according to the respiratory rate. Arterial blood gases were analyzed before, during, and after O2 supplementation. A 10-min washout period was allowed between treatment groups. All three treatments adequately treated hypoxemia. The partial pressure of arterial oxygenation increased significantly from baseline values of 55 +/- 10 to 115 +/- 31 mm Hg during supplementation from the oxygen concentrator, to 138 +/- 21 mm Hg during supplementation from the oxygen cylinder at 1 L/min, and to 201 +/- 42 mm Hg at 2 L/min. In conclusion, low flow rates of intranasal oxygen supplemented continuously from an oxygen cylinder or by pulsed delivery from a portable oxygen concentrator effectively treated hypoxemia in anesthetized white-tailed deer.

Dietary supplementation of female rats with elk velvet antler improves physical and neurological development of offspring.

Elk velvet antler (EVA) has a traditional use for promotion of general health. However, evidence of EVA effects at different lifestages is generally lacking. This paper investigated the effects of long-term maternal dietary EVA supplementation on physical, reflexological and neurological development of rat offspring. Female Wistar rats were fed standard chow or chow containing 10% EVA for 90 days prior to mating and throughout pregnancy and lactation. In each dietary group, 56 male and 56 female pups were assessed for physical, neuromotor, and reflexologic development postnatally. Among the examined physical developmental parameters, incisor eruption occurred one day earlier in pups nursing dams receiving EVA. Among neuromotor developmental parameters, duration of supported and unsupported standing was longer for pups nursing EVA supplemented dams. Acquisition of neurological reflex parameters (righting reflex, negative geotaxis, cliff avoidance acoustic startle) occurred earlier in pups nursing dams receiving EVA. Longterm maternal EVA supplementation prior to and during pregnancy and lactation accelerated certain physical, reflexologic, and neuromotor developmental milestones and caused no discernible adverse effects on developing offspring. The potential benefits of maternal EVA supplementation on postnatal development warrants further investigation to determine whether EVA can be endorsed for the promotion of maternal and child health.

Toxocara vitulorum in a bison (Bison bison) herd from western Canada.

The discovery of the parasite Toxocara vitulorum in bison calves in the province of Manitoba, Canada is discussed. This parasite is more commonly found in the small intestines of bovid calves living in tropical and subtropical regions of the world. This is the first time that Toxocara vitulorum has been reported from hosts in Canada.

Evaluation of a minimally invasive arthrodesis technique for the carpometacarpal joint in horses.

OBJECTIVE: To evaluate a minimally invasive technique for arthrodesis of the carpometacarpal (CMC) joint in horses. STUDY DESIGN: Experimental study. ANIMALS: Healthy horses (n=6). METHODS: A 5.5 mm, 3-drill tract arthrodesis technique was evaluated in 1 randomly selected CMC joint in each of 6 normal horses. Peak vertical ground reaction force (GRF) values were recorded before surgery and at 6, 8, and 12 months thereafter. Radiographic and clinical lameness scores were assigned at regular intervals until 12 months after surgery when the horses were euthanatized. Gross and histologic examinations were performed on the treated CMC joints. RESULTS: After surgery, all horses were lame. Clinical resolution of lameness occurred in 2 by 12 months. Mean peak vertical GRF values significantly differed between treated and nontreated limbs at all recorded time points after surgery. Radiographic scores significantly differed from day 0 at all times after surgery, but did not change significantly after 4 months. Intraarticular bony ankylosis only occurred in 2 horses, based on gross, histologic, and microradiographic examination of sagittal sections of the operated CMC joints. CONCLUSION: The 5.5 mm, 3-drill tract arthrodesis technique was considered successful in only 2 of 6 normal CMC joints treated. Greater articular damage may be necessary to achieve arthrodesis in normal horses. Better results may be achieved by technique modification or in horses affected by CMC osteoarthritis.

A survey of the fecal bacteria of bison (Bison bison) for potential pathogens and antimicrobial susceptibility of bison-origin E. coli.

An observational study determined the normal fecal bacterial flora of clinically healthy bison, detected the presence of common potential zoonotic pathogens, and determined the antimicrobial susceptibility of isolated E. coli strains. Ninety-six fecal samples from 10 captive herds were cultured for aerobic, anaerobic, facultative, and microaerophillic bacteria. Nineteen major genera of gram-positive and 8 genera of gram-negative bacteria were identified. Salmonella spp. were not detected but some of the isolated bacteria are potential gastrointestinal pathogens. Minimum inhibitory concentrations (MIC) of 24 antimicrobials were determined for the E. coli isolated. Nearly all were susceptible to 23 of the 24 antimicrobials but there was a reduced susceptibility to sulphonamide. There were fewer resistant strains than were reported in recent studies of generic E. coli from cattle living in the same area.

The efficacy of pour-on ivermectin in bison (Bison bison).

To test the effectiveness of pour-on ivermectin in parasitized bison, changes in fecal parasite egg counts after treatment with ivermectin injectable or pour-on preparations were compared to a negative control group. There was no difference between the two ivermectin groups, and both forms of ivermectin were effective in reducing fecal parasite egg counts in parasitized bison.

Selenium toxicosis in a white-tailed deer herd.

Chronic selenium (Se) toxicosis was found in a herd of white-tailed deer showing signs of anorexia, weight loss, and lameness. Concentration of Se in the liver ranged from 2.7 to 8.97 mg/kg wet weight. Myocardial necrosis, mineralization, and fibroplasia were seen histologically. This is the first report of this toxicosis in white-tailed deer.

Traceback of the Psoroptes outbreak in British Columbian bighorn sheep (Ovis Canadensis).

Psoroptes are a non-burrowing, ectoparasitic, mange-causing mite that has been documented in American bighorn sheep populations throughout the 19th and 20th centuries; however, it was not seen on Canadian bighorn sheep until 2006. The aim of this study was to determine the potential source of the Psoroptes outbreak in Canadian bighorn sheep. Morphological and molecular analyses were used to compare mites recovered from outbreak-associated bighorn sheep, pet rabbits in Canada, and on historically infested bighorn sheep in the USA. The results revealed that Psoroptes acquired from the Canadian and outbreak-associated American bighorn sheep were morphologically more similar to those collected from rabbits than mites on historically infested bighorn sheep. Outer opisthosomal setae lengths measured an average of 81.7 µm (±7.7 µm) in outbreak associated bighorn mites, 88.9 µm (±12.0 µm) in rabbit mites and 151.2 µm (±16.6 µm) in historically infested bighorn mites. The opisthosomal lobe morphology of bighorn mites in the outbreak herds was also more similar to that of rabbit mites, previously described as P. cuniculi, than historically infested bighorn mites, which match previous descriptions of P. ovis. This finding was supported by DNA sequence data of the mitochondrial cytochrome B gene. This is the first report of Psoroptes of the rabbit ecotype on bighorn sheep. The morphological and molecular data therefore support the hypothesis that the source of Psoroptes outbreak in Canadian bighorn sheep represented a disease spillover event from rabbits rather than transmission from infested American bighorn sheep populations.

Prevalence of Mycoplasma spp. in the Respiratory Tract of Healthy North American Bison (Bison bison) and Comparison with Serum Antibody Status.

Mycoplasma bovis is a primary cause of respiratory and reproductive diseases in North American bison (Bison bison), with significant morbidity and mortality. The epidemiology of M. bovis in bison is poorly understood, hindering efforts to develop effective control measures. Our study considered whether healthy bison might be carriers of M. bovis, potentially serving as unrecognized sources of exposure. We used culture and PCR to identify mycoplasmas in the nasal cavity or tonsil of 499 healthy bison from 13 herds and two abattoirs in the US and Canada. Mycobacterium bovis was detected in 15 bison (3.0%) representing two herds in the US and one in Canada, while M. bovirhinis, M. bovoculi, M. arginini, or M. dispar was identified from an additional 155 bison (31.1%). Mycoplasma bovirhinis was identified most frequently, in 142 bison (28.5%) representing at least 10 herds. Of the 381 bison for which serum was available, only 6/13 positive for M. bovis (46.2%) tested positively with an M. bovis ELISA, as did 19/368 negative for M. bovis (5.2%). Our data reveal that M. bovis can be carried in the upper respiratory tract of healthy bison with no prior history or clinical signs of mycoplasmosis and that a large proportion of carriers may not produce detectable antibodies. Whether carriage of other mycoplasmas can trigger cross-reactive antibodies that may confound M. bovis serology requires further study.

Intranasal naltrexone and atipamezole for reversal of white-tailed deer immobilized with carfentanil and medetomidine.

Carfentanil and medetomidine were used to immobilize 8 captive female white-tailed deer (Odocoileus virginianus) using mean dosages [+/- standard deviation (s)] of 14.2 +/- 1.11 microg/kg carfentanil and 17.8 +/- 2.03 microg/kg of medetomidine. Deer were reversed by intranasally or intramuscularly administered naltrexone and atipamezole. Dosages of carfentanil and medetomidine proved reliable for immobilization of most, but not all deer, with a mean induction time of 13.3 +/- 3.13 min. Effective and reliable immobilization will require higher dosages of carfentanil and possibly medetomidine than were used in this study. No significant differences in recovery times were observed for deer given reversal agents intranasally (9.45 +/- 5.37 min) versus intramuscularly (7.60 +/- 4.42 min). Naltrexone and atipamezole can be administered intranasally at 1.5 mg/kg and 0.1 mg/kg, respectively to safely and quickly reverse the effects of carfentanil and medetomidine in immobilized white-tailed deer. This route could potentially be useful for other reversal agents.

Complete Genome Sequences of 16 Mycoplasma bovis Isolates from Canadian Bison and Cattle.

Here, we report the complete genome sequences of 12 Mycoplasma bovis isolates cultured from Canadian bison and 4 cultured from Canadian cattle. The sequences are of value for understanding the phylogenetic relationship between cattle and bison isolates and will aid in elucidating the genetic basis for virulence and host specificity.

Comparison of three drilling techniques for carpometacarpal joint arthrodesis in horses.

OBJECTIVE: To evaluate 3 drilling techniques for arthrodesis of the equine carpometacarpal (CMC) joint. STUDY DESIGN: Experimental study. SAMPLE POPULATION: Cadaveric equine forelimbs (n=15). METHODS: Limbs were divided into 3 groups (5 limbs each) to evaluate 3 drilling techniques: (1) use of a 4.5 mm drill bit inserted into the joint through 4 entry points and moved in a fanning motion; (2) a 5.5 mm drill bit inserted through 2 entry points to create 3 nonfanned drill tracts (3 drill technique); and (3) a 4.5 mm drill bit used in a 3 drill technique. The CMC joint was disarticulated after drilling, and cartilage and subchondral bone damage evaluated visually and by gross and microradiographic examination using planimetry. RESULTS: Technique 1 produced significantly more damage of the proximal surface, but significantly less to the subchondral bone of the distal surface. Technique 1 produced the most damage to both the articular cartilage and subchondral bone of the total CMC joint than either of the 3 drill tract techniques; however, the difference between techniques 1 and 2 was not significant. Damage from technique 3 was significantly less than that with techniques 1 or 2. CONCLUSIONS: Techniques 1 and 2 produced the most cartilage and subchondral bone damage with technique 2 changes more equally distributed between proximal and distal joint surfaces. CLINICAL RELEVANCE: Technique 1 (fanning) and 2 (5.5 mm 3 drill tracts) may be preferable to achieve arthrodesis of the CMC joint. Morbidity and efficacy of these arthrodesis techniques need to be evaluated in vivo.