Variation of hair cortisol in two herds of migratory caribou (Rangifer tarandus): implications for health monitoring.

Migratory caribou (Rangifer tarandus sspp.) is an ecotype of conservation concern that is experiencing increased cumulative stressors associated with rapid climate change and development in Arctic Canada. Increasingly, hair cortisol concentrations (HCCs) are being used to monitor seasonal hypothalamic-pituitary-adrenal axis activity of ungulate populations; yet, the effect of key covariates for caribou (sex, season, sampling source, body location) are largely unknown. The objectives of this research were 4-fold: first, we assessed the impact of body location (neck, rump) sampling sites on HCC; second, we assessed key covariates (sex, sampling method, season) impacting HCCs of caribou; third, we investigated inter-population (Dolphin and Union (DU), Bluenose-East (BNE)) and inter-annual differences in HCC and fourth, we examined the association between HCCs and indices of biting insect activity on the summer range (oestrid index, mosquito index). We examined hair from 407 DU and BNE caribou sampled by harvesters or during capture-collaring operations from 2012 to 2020. Linear mixed-effect models were used to assess the effect of body location on HCC and generalized least squares regression (GLS) models were used to examine the impacts of key covariates, year and herd and indices of biting insect harassment. HCC varied significantly by body location, year, herd and source of samples (harvester vs capture). HCC was higher in samples taken from the neck and in the DU herd compared with the BNE, decreased linearly over time and was higher in captured versus hunted animals (P < 0.05). There was no difference in HCC between sexes, and indices of biting insect harassment in the previous year were not significantly associated with HCC. This study identifies essential covariates impacting the HCC of caribou that must be accounted for in sampling, monitoring and data interpretation.

Occurrence of Mycobacterium avium subspecies paratuberculosis and Neospora caninum in Alberta cow-calf operations.

Mycobacterium avium subsp. paratuberculosis (MAP) and Neospora caninum (NC) are two pathogens causing important production limiting diseases in the cattle industry. Significant impacts of MAP and NC have been reported on dairy cattle herds, but little is known about the importance, risk factors and transmission patterns in western Canadian cow-calf herds. In this cross-sectional study, the prevalence of MAP and NC infection in southwest Alberta cow-calf herds was estimated, risk factors for NC were identified, and the reproductive impacts of the two pathogens were assessed. Blood and fecal samples were collected from 840 cows on 28 cow-calf operations. Individual cow and herd management information was collected by self-administered questionnaires and one-on-one interviews. Bayesian estimates of the true prevalence of MAP and NC were computed, and bivariable and multivariable statistical analysis were done to assess the association between the NC serological status and ranch management risk factors, and the clinical effects of the two pathogens. Bayesian estimates of true prevalence indicated that 20% (95% probability interval: 8-38%) of herds had at least one MAP-positive cow, with a within-herd prevalence in positive herds of 22% (8-45%). From the Bayesian posterior distributions of NC prevalence, the median herd-level prevalence was 66% (33-95%) with 10% (4-21%) cow-level prevalence in positive herds. Multivariable analysis indicated that introducing purchased animals in the herd might increase the risk of NC. The negative association of NC with proper carcass disposal and presence of horses on ranch (possibly in relation to herd monitoring and guarding activities), may suggest the importance of wild carnivores in the dynamics of this pathogen in the study area. We also observed an association between MAP and NC serological status and the number of abortions. Additional studies should be done to further examine specific risk factors for MAP and NC, assess the consequences on the reproductive performances in cow-calf herds, and evaluate the overall impact of these pathogens on cow-calf operations.

What attracts elk onto cattle pasture? Implications for inter-species disease transmission.

In Southwest Alberta, beef cattle and wild elk (Cervus elaphus) have similar habitat preferences. Understanding their inter-species contact structure is important for assessing the risk of pathogen transmission between them. These spatio-temporal patterns of interactions are shaped, in part, by range management and environmental factors affecting elk distribution. In this study, resource selection modeling was used to identify factors influencing elk presence on cattle pasture and elk selection of foraging patches; furthermore, consequences for inter-species disease transmission were discussed. Data on pasture management practices and observations of elk were collected from 15 ranchers during interviews. Pasture use by elk was defined based on telemetry data (from GPS collars deployed on 168 elk in 7 herds) and rancher observations. At the patch scale, foraging patches used by elk were identified by spatio-temporal cluster analysis of telemetry data, whereas available patches were randomly generated outside the area delimited by used patches. For pastures and patches, landscape and human-managed features were characterized using remote sensing data and interviews, respectively. Attributes of available and used pastures (or patches) were compared using resource selection functions, on annual and seasonal (or annual and monthly) time scales. Additionally, intensity of pasture use was modeled using negative binomial regression. Cultivated hay land and mineral supplements were associated with elk presence on cattle pastures, whereas pastures with manure fertilization and higher traffic-weighted road densities were less likely to be used by elk. The effects of landscape (elevation, aspect, water access) and vegetation (forest cover, Normalized Difference Vegetation Index) characteristics on patch selection were consistent with typical elk habitat requirements. The presence of cattle and the traffic-weighted road density were negatively associated with patch selection. The apparent avoidance of cattle by elk reduced the risk of direct transmission of pathogens, except during winter months. However, human-managed features attracting elk to cattle pastures (e.g. hay land and mineral supplements) may increase inter-species pathogen transmission through indirect contacts.

Risk of biliary complications in bariatric surgery.

Gallstones are commonly observed after rapid weight loss, particularly after bariatric surgery. Preventive measures of gallstone formation and potential related complications are still debated. This study aimed to propose a standardized strategy according to the results of the literature. Thus, preventive measures should be determined according to patient status (evaluated clinically and by routine ultrasound) and the type of bariatric surgery. Cholecystectomy should be performed in patients with symptomatic gallstones irrespective of the planned operation, or for asymptomatic gallstones during a gastric by-pass. In other settings, ursodesoxycholic acid should be given postoperatively for 6 months.

[Familial forms of intracranial cavernous hemangioma. Apropos of 5 cases in 2 families]. / Formes familiales des hémangiomes caverneux intracrâniens. A propos de 5 cas dans deux familles.

The authors report five cases of cavernous hemangioma belonging to two families. In the first family, an 8 year old child was operated on in 1970 for a left frontal location. His mother, aged 39, was operated on in december, 1981, with stereotaxic approach, for two locations: one was frontal location, the other one was in the pineal region. Among the second family, a 21 year old woman was operated on in december 1976, for a cerebellar cavernous hemangioma. Her sister, aged 18, presented with subarachnoid hemorrhage in january 1980. C.T. scan showed a right temporal high attenuation area. This patient was not operated on. The aunt to those two sisters was operated on in october, 1981, for a left temporal cavernous hemangioma. Those five cases represent about half of the intracranial cavernous hemangiomas operated on in the Lille Neurosurgery Department since 1967. Even, unusual, the familial occurrence of this affection must be admitted. It shows a nosological interest, but also allows prevention by searching and surveying the asymptomatic cases, or genetic evaluation of disease risk.