Can intake data inform on impacts of repeated subsidized onsite spay-neuter clinics for dogs?

Objective: Subsidized dog care and population management programs (DPM) are often implemented for dog population control where for-profit veterinary care is inaccessible. However, impacts of such programs are rarely assessed. The goal of this project was to determine if and how previously collected intake data from ongoing high-volume spay-neuter clinics could be used to measure impacts of such DPM programs. Animals: We used intake data collected from 2008 to 2019 from spay-neuter clinics that had been delivered repeatedly over a 10-year period in 6 First Nations communities in Alberta, to assess changes in intake dog characteristics. Procedures: Numbers of dogs brought in for spay-neuter surgery or surrendered, and their ages, sexes, breeds, weights, and body condition scores were compared. Reasons for surrender were investigated and socioeconomic factors were investigated as possible drivers for community differences in clinic participation rates and clinic sex ratios. Results: Socioeconomic indicators did not differ between the 6 participating communities; however, the total number of clinics requested by communities varied. In early years, female dogs were more likely to be brought to the clinics to be spayed whereas, in later years, more males were seen. The age at which animals were brought in for spay or neuter decreased over time (P < 0.05) but the surrender age did not. Breed proportions of x-large, small, and x-small breeds varied over time for both spay-neuter and surrender dogs (P < 0.05), with large-breed dogs always being the most common. However, there was an increase in small and x-small breeds in the final years of the study. Finally, weight status, a calculated estimate of body condition of spay-neuter dogs, increased over time within large and medium breeds, whereas the body condition score of surrendered dogs shifted from "thin" to "ideal" over time. Conclusions and clinical relevance: This work highlights the potential and challenges of using intake data to assess impacts of spay-neuter clinics that occur repeatedly over many years in the same communities. Overall increased weight status, high participation rates, and reduction of age at intake suggest positive effects of the assessed spay-neuter programs.

Les données d'admission peuvent-elles renseigner sur les impacts des cliniques de stérilisation sur place pour les chiens répétées et subventionnées? Objectif: Des programmes subventionnés de soins canins et de gestion de la population (DPM) sont souvent mis en œuvre pour limiter la population canine là où les soins vétérinaires à but lucratif sont inaccessibles. Cependant, les impacts de ces programmes sont rarement évalués. L'objectif de ce projet était de déterminer si et comment les données d'admission précédemment collectées dans les cliniques de stérilisation à grand volume en cours pourraient être utilisées pour mesurer les impacts de tels programmes de DPM. Animaux: Nous avons utilisé les données d'admission recueillies de 2008 à 2019 dans des cliniques de stérilisation qui avaient été dispensées à plusieurs reprises sur une période de 10 ans dans 6 communautés des Premières Nations de l'Alberta, pour évaluer les changements dans les caractéristiques d'admission des chiens. Procédures: Le nombre de chiens amenés pour une chirurgie de stérilisation ou cédés, ainsi que leurs âges, sexes, races, poids et scores de condition physique ont été comparés. Les raisons de l'abandon ont été étudiées ainsi que les facteurs socio-économiques en tant que facteurs possibles des différences communautaires dans les taux de participation aux cliniques et les ratios des sexes entre les cliniques. Résultats: Les indicateurs socioéconomiques ne différaient pas entre les 6 communautés participantes; cependant, le nombre total de cliniques demandées par les communautés variait. Au cours des premières années, les chiennes étaient plus susceptibles d'être amenées aux cliniques pour être stérilisées, tandis que dans les années suivantes, davantage de mâles étaient vus. L'âge auquel les animaux ont été amenés pour la castration ou la stérilisation a diminué avec le temps (P < 0,05), mais pas l'âge d'abandon. Les proportions de races très grandes, petites et très petites variaient au fil du temps pour les chiens stérilisés et les chiens abandonnés (P < 0,05), les chiens de grande race étant toujours les plus courants. Cependant, il y a eu une augmentation des races petites et très petites au cours des dernières années de l'étude. Enfin, le statut pondéral, une estimation calculée de la condition corporelle des chiens stérilisés, a augmenté avec le temps au sein des races grandes et moyennes, tandis que le score de condition corporelle des chiens abandonnés est passé de « mince ¼ à « idéal ¼ au fil du temps. Conclusions et pertinence clinique: Ce travail met en évidence le potentiel et les défis liés à l'utilisation des données d'admission pour évaluer les impacts des cliniques de stérilisation qui se déroulent à plusieurs reprises sur de nombreuses années dans les mêmes communautés. L'augmentation globale du statut pondéral, les taux de participation élevés et la réduction de l'âge à l'admission suggèrent des effets positifs des programmes de stérilisation évalués.(Traduit par Dr Serge Messier).

Local thermal adaptation and local temperature regimes drive the performance of a parasitic helminth under climate change: The case of Marshallagia marshalli from wild ungulates.

Across a species' range, populations are exposed to their local thermal environments, which on an evolutionary scale, may cause adaptative differences among populations. Helminths often have broad geographic ranges and temperature-sensitive life stages but little is known about whether and how local thermal adaptation can influence their response to climate change. We studied the thermal responses of the free-living stages of Marshallagia marshalli, a parasitic nematode of wild ungulates, along a latitudinal gradient. We first determine its distribution in wild sheep species in North America. Then we cultured M. marshalli eggs from different locations at temperatures from 5 to 38°C. We fit performance curves based on the metabolic theory of ecology to determine whether development and mortality showed evidence of local thermal adaptation. We used parameter estimates in life-cycle-based host-parasite models to understand how local thermal responses may influence parasite performance under general and location-specific climate-change projections. We found that M. marshalli has a wide latitudinal and host range, infecting wild sheep species from New Mexico to Yukon. Increases in mortality and development time at higher temperatures were most evident for isolates from northern locations. Accounting for location-specific parasite parameters primarily influenced the magnitude of climate change parasite performance, while accounting for location-specific climates primarily influenced the phenology of parasite performance. Despite differences in development and mortality among M. marshalli populations, when using site-specific climate change projections, there was a similar magnitude of impact on the relative performance of M. marshalli among populations. Climate change is predicted to decrease the expected lifetime reproductive output of M. marshalli in all populations while delaying its seasonal peak by approximately 1 month. Our research suggests that accurate projections of the impacts of climate change on broadly distributed species need to consider local adaptations of organisms together with local temperature profiles and climate projections.

Life history matters: Differential effects of abomasal parasites on caribou fitness.

Parasites can impact wildlife populations through their effects on host fitness and survival. The life history strategies of a parasite species can dictate the mechanisms and timing through which it influences the host. However, unravelling this species-specific effect is difficult as parasites generally occur as part of a broader community of co-infecting parasites. Here, we use a unique study system to explore how life histories of different abomasal nematode species may influence host fitness. We examined abomasal nematodes in two adjacent, but isolated, West Greenland caribou (Rangifer tarandus groenlandicus) populations. One herd of caribou were naturally infected with Ostertagia gruehneri, a common and dominant summer nematode of Rangifer sspp., and the other with Marshallagia marshalli (abundant; winter) and Teladorsagia boreoarcticus (less abundant; summer), allowing us to determine if these nematode species have differing effects on host fitness. Using a Partial Least Squares Path Modelling approach, we found that in the caribou infected with O. gruehneri, higher infection intensity was associated with lower body condition, and that animals with lower body condition were less likely to be pregnant. In caribou infected with M. marshalli and T. boreoarcticus, we found that only M. marshalli infection intensity was negatively related to body condition and pregnancy, but that caribou with a calf at heel were more likely to have higher infection intensities of both nematode species. The differing effects of abomasal nematode species on caribou health outcomes in these herds may be due to parasite species-specific seasonal patterns which influence both transmission dynamics and when the parasites have the greatest impact on host condition. These results highlight the importance of considering parasite life history when testing associations between parasitic infection and host fitness.

Actualizing Cultural Humility: An Exploratory Study of Veterinary Students' Participation in a Northern Community Health Rotation.

Rotations in diverse, marginalized communities may offer health care students opportunities to develop cultural humility through different clinical experiences and activities. Through the actualization of cultural humility, veterinarians may offer accessible, affordable, culturally proficient, high-quality care to all their patients with a better understanding of how cultural differences affect the animal patient's health, well-being, and care. The purpose of this study was to explore whether participation in a community rotation in remote northern Indigenous communities promotes cultural humility among final-year veterinary students. Small groups of University of Calgary veterinary students travel annually to the Sahtu Settlement Area of the Northwest Territories, Canada, to participate in the Northern Community Health Rotation (NCHR). During the 4-week rotation, students spend 2.5 weeks providing veterinary services to domestic animals in five communities in the Sahtu. Eleven veterinary students who attended the NCHR between 2015 and 2020 answered exploratory open-ended questions in an online survey. Responses highlight areas of learning that contributed to their development of cultural humility. The rotation appears successful in increasing students' confidence working with people from diverse cultures, offering students opportunities to implement a client-centered approach, and advancing their capacity to recognize and challenge their preconceived biases about Indigenous cultures and animal ownership. These experiences are important to the acquisition of cultural humility for veterinary care providers.

Behaviour is more important than thermal performance for an Arctic host-parasite system under climate change.

Climate change is affecting Arctic ecosystems, including parasites. Predicting outcomes for host-parasite systems is challenging due to the complexity of multi-species interactions and the numerous, interacting pathways by which climate change can alter dynamics. Increasing temperatures may lead to faster development of free-living parasite stages but also higher mortality. Interactions between behavioural plasticity of hosts and parasites will also influence transmission processes. We combined laboratory experiments and population modelling to understand the impacts of changing temperatures on barren-ground caribou (Rangifer tarandus) and their common helminth (Ostertagia gruehneri). We experimentally determined the thermal performance curves for mortality and development of free-living parasite stages and applied them in a spatial host-parasite model that also included behaviour of the parasite (propensity for arrested development in the host) and host (long-distance migration). Sensitivity analyses showed that thermal responses had less of an impact on simulated parasite burdens than expected, and the effect differed depending on parasite behaviour. The propensity for arrested development and host migration led to distinct spatio-temporal patterns in infection. These results emphasize the importance of considering behaviour-and behavioural plasticity-when projecting climate-change impacts on host-parasite systems.

MORPHOMETRY OF FIRST-STAGE LARVAE OF ORTHOSTRONGYLUS MACROTIS (NEMATODA: PROTOSTRONGYLIDAE), LUNGWORM OF WILD UNGULATES FROM WESTERN NORTH AMERICA.

Orthostrongylus macrotis (Dikmans, 1931) is a protostrongylid lungworm in wild ungulates from western North America, including mule and Columbia black-tailed deer, pronghorn, and rarely moose and elk. The lack of morphological data for certain developmental stages of O. macrotis and the unresolved taxonomic status of the genus indicate a more detailed morphological characterization of the species is necessary. We provide a detailed description of first-stage larvae (L1) of O. macrotis including morphological, morphometric, and molecular data. Species identity was confirmed based on molecular sequence data from the internal transcribed spacer subunit 2 (ITS-2) and large subunit (28S) rDNA. A fragment of the cytochrome oxidase c subunit 1 (COI) was also sequenced, followed by the determination of genetic distance and phylogenetic analyses. Integrated data describing L1 of O. macrotis contributes to a broader understanding of the parasite fauna of wild ungulates from North America and may be of relevance for a future revision of the genus. Further, we outline information for differentiation among species of North American protostrongylids, with typical spike-tailed L1s, circulating among free-ranging and semi-domestic ungulates.

Congenital cataract and spherophakia leading to starvation in a free-ranging muskox neonate from the Northwest Territories, Canada.

A muskox neonate (Ovibos moschatus) that died of starvation was diagnosed with congenital lenticular anomalies that included spherophakia and hypermature cataract associated with probable lens-induced lymphocytic uveitis and neutrophilic keratitis. Impaired sight as a result of cataract and associated inflammation likely contributed to abandonment and starvation, although maternal death cannot be excluded definitively. Ocular lesions, such as congenital cataracts and spherophakia in neonates, may be important factors affecting survival in free-ranging animals.

Corynebacterium freneyi Bacterial Septicemia Secondary to Contagious Ecthyma in a Wild Muskox (Ovibos moschatus).

A wild muskox (Ovibos moschatus) with dermatitis typical of contagious ecthyma had secondary bacterial septicemia with Corynebacterium freneyi that included laminitis, hepatitis, and suppurative encephalitis. This case supports the association between orf virus infection and fatal secondary infections, which may have contributed to population declines on Victoria Island, Canada.

Correction: Novel insights into serodiagnosis and epidemiology of Erysipelothrix rhusiopathiae, a newly recognized pathogen in muskoxen (Ovibos moschatus).

[This corrects the article DOI: 10.1371/journal.pone.0231724.].

Living with liver flukes: Does migration matter?

Migration is typically thought to be an evolved trait driven by responses to forage or predation, but recent studies have demonstrated avoidance of parasitism can also affect success of migratory tactics within a population. We evaluated hypotheses of how migration alters parasite exposure in a partially migratory elk (Cervus canadensis) population in and adjacent to Banff National Park, Alberta, Canada. Equal numbers of elk remain year-round on the winter range or migrate to summer range. We quantified diversity and abundance of parasites in faecal elk pellets, and prevalence (number of infected individuals) and intensity (egg counts) of giant liver fluke eggs (Fascioloides magna) in faeces across migratory tactics. We tested whether giant liver fluke intensity in faeces was affected by elk use of wetlands, elevation, forage biomass, and elk concentration in the previous summer. We rejected the "migratory escape" hypothesis that suggests migration allowed elk to escape parasite exposure because migrant elk had the highest richness and evenness of parasite groups. We also rejected the hypothesis that prevalence was highest at highest summer densities because higher-density resident elk had the lowest diversity and giant liver fluke egg presence and intensity. Instead, the high prevalence and intensity of giant liver flukes in migrants was consistent with both the hypothesis of "environmental tracking", because elk that migrated earlier may expose themselves to favourable parasite conditions, and with the "environmental sampling" hypothesis, because giant liver fluke intensity increased with increased exposure to secondary host habitat (i.e., wetland). Our results indicate that differential exposure of different migratory tactics that leave the winter range has a greater influence on parasites than the concentration of elk that reside on the winter range year-round.

Novel insights into serodiagnosis and epidemiology of Erysipelothrix rhusiopathiae, a newly recognized pathogen in muskoxen (Ovibos moschatus).

BACKGROUND: Muskoxen are a key species of Arctic ecosystems and are important for food security and socio-economic well-being of many Indigenous communities in the Arctic and Subarctic. Between 2009 and 2014, the bacterium Erysipelothrix rhusiopathiae was isolated for the first time in this species in association with multiple mortality events in Canada and Alaska, raising questions regarding the spatiotemporal occurrence of the pathogen and its potential impact on muskox populations. MATERIALS AND METHODS: We adapted a commercial porcine E. rhusiopathiae enzyme-linked immunosorbent assay to test 958 blood samples that were collected from muskoxen from seven regions in Alaska and the Canadian Arctic between 1976 and 2017. The cut-off between negative and positive results was established using mixture-distribution analysis, a data-driven approach. Based on 818 samples for which a serological status could be determined and with complete information, we calculated trends in sample seroprevalences in population time-series and compared them with population trends in the investigated regions. RESULTS: Overall, 219/818 (27.8%, 95% Confidence Interval: 24.7-31.0) samples were classified as positive for exposure to E. rhusiopathiae. There were large variations between years and regions. Seropositive animals were found among the earliest serum samples tested; 1976 in Alaska and 1991 in Canada. In Alaskan muskoxen, sample seroprevalence increased after 2000 and, in two regions, peak seroprevalences occurred simultaneously with population declines. In one of these regions, concurrent unusual mortalities were observed and E. rhusiopathiae was isolated from muskox carcasses. In Canada, there was an increase in sample seroprevalence in two muskox populations following known mortality events that had been attributed to E. rhusiopathiae. CONCLUSION: Our results indicate widespread exposure of muskoxen to E. rhusiopathiae in western Canada and Alaska. Although not new to the Arctic, we documented an increased exposure to the pathogen in several regions concurrent with population declines. Understanding causes for the apparent increased occurrence of this pathogen and its association with large scale mortality events for muskoxen is critical to evaluate the implications for wildlife and wildlife-dependent human populations in the Arctic.

The biogeography of the caribou lungworm, Varestrongylus eleguneniensis (Nematoda: Protostrongylidae) across northern North America.

Varestrongylus eleguneniensis (Nematoda; Protostrongylidae) is a recently described species of lungworm that infects caribou (Rangifer tarandus), muskoxen (Ovibos moschatus) and moose (Alces americanus) across northern North America. Herein we explore the geographic distribution of V. eleguneniensis through geographically extensive sampling and discuss the biogeography of this multi-host parasite. We analyzed fecal samples of three caribou subspecies (n = 1485), two muskox subspecies (n = 159), and two moose subspecies (n = 264) from across northern North America. Protostrongylid dorsal-spined larvae (DSL) were found in 23.8%, 73.6%, and 4.2% of these ungulates, respectively. A portion of recovered DSL were identified by genetic analyses of the ITS-2 region of the nuclear rDNA or the cytochrome oxidase c subunit I (COI) region of the mtDNA. We found V. eleguneniensis widely distributed among caribou and muskox populations across most of their geographic prange in North America but it was rare in moose. Parelaphostrongylus andersoni was present in caribou and moose and we provide new geographic records for this species. This study provides a substantial expansion of the knowledge defining the current distribution and biogeography of protostrongylid nematodes in northern ungulates. Insights about the host and geographic range of V. eleguneniensis can serve as a geographically extensive baseline for monitoring current distribution and in anticipating future biogeographic scenarios under a regime of accelerating climate and anthropogenic perturbation.

Historical biogeography among species of Varestrongylus lungworms (Nematoda: Protostrongylidae) in ungulates: episodic expansion and host colonization linking Eurasia and North America.

Varestrongylus lungworms (Nematoda: Protostrongylidae) include 10 nominal species that parasitize wild and domesticated artiodactyles. Eight species are endemic to the western Palearctic and Eurasia, whereas two are limited in distribution to the Nearctic. Complex host associations, primarily among Cervidae and Bovidae (Caprinae), and biogeography were explored based on direct comparisons of parasite and host phylogenies to reveal the historical development of this fauna. Diversification among Varestrongylus species has an intricate history extending over the Pliocene and Quaternary involving episodic processes for geographic and host colonization: (1) Varestrongylus has origins in Eurasia with independent expansion events into bordering ecozones; (2) cervids are ancestral hosts; (3) the caprine-associated V. pneumonicus is basal and a result of an independent host colonization event; (4) secondary diversification, linked to sequential and independent host colonization events, occurred within cervids (V. sagittatus + V. tuvae; V. alpenae; and V. capreoli, V. alces + V. eleguneniensis); (5) at least two additional host colonization events into caprines occurred, followed or not by diversification (V. qinghaiensis + V. longispiculatus; V. capricola, respectively); (6) two independent events of geographic expansion into North America from Eurasia with cervids in the late Pliocene and early Pleistocene are postulated (V. alpenae, V. eleguneniensis). Comparisons based on phylogenetic hypotheses derived from comparative morphology and molecular inference for these nematodes are consistent with the postulated history for coevolutionary and biogeographic history. Episodes of geographic and host colonization, often in relation to rapid shifts in climate and habitat perturbation, have dominated the history of diversification of Varestrongylus.

Varestrongylus (Nematoda: Protostrongylidae), lungworms of ungulates: a phylogenetic framework based on comparative morphology.

Varestrongylus Bhalerao, 1932 comprises ten valid lungworm species infecting wild and domestic ungulates from Eurasia and North America. Here, we present a phylogenetic hypothesis for the genus based on morphological characters in a broader context for the family Protostrongylidae and discuss species relationships and aspects of character evolution. Phylogenetic analysis of 25 structural attributes, including binary and multistate characters, among the 10 species of Varestrongylus resulted in one fully resolved most parsimonious tree (61 steps; consistency index = 0.672, retention index = 0.722, and consistency index excluding uninformative characters = 0.667). Varestrongylus forms a monophyletic clade and is the sister of Pneumostrongylus, supporting recognition of the subfamily Varestrongylinae. Monophyly for Varestrongylus is diagnosed by six unequivocal synapomorphies, all associated with structural characters of the copulatory system of males. Varestrongylus pneumonicus is basal, and sister to all other species within the genus, which form two subclades. The subclade I contains V. sagittatus + V. tuvae and V. qinghaiensis + V. longispiculatus. Subclade II contains V. alpenae, V. capricola, V. capreoli, and V. eleguneniensis + V. alces. Both subclades are diagnosed by two unambiguous synapomorphies. Highlighted is the continuing importance of phylogenetic assessments based on comparative morphology as a foundation to explore the structure of the biosphere across space and time.

Diversity of gastrointestinal helminths in Dall's sheep and the negative association of the abomasal nematode, Marshallagia marshalli, with fitness indicators.

Gastrointestinal helminths can have a detrimental effect on the fitness of wild ungulates. Arctic and Subarctic ecosystems are ideal for the study of host-parasite interactions due to the comparatively simple ecological interactions and limited confounding factors. We used a unique dataset assembled in the early seventies to study the diversity of gastrointestinal helminths and their effect on fitness indicators of Dall's sheep, Ovis dalli dalli, in the Mackenzie Mountains, Northwest Territories, Canada. Parasite diversity included nine species, among which the abomasal nematode Marshallagia marshalli occurred with the highest prevalence and infection intensity. The intensity of M. marshalli increased with age and was negatively associated with body condition and pregnancy status in Dall's sheep across all the analyses performed. The intensity of the intestinal whipworm, Trichuris schumakovitschi, decreased with age. No other parasites were significantly associated with age, body condition, or pregnancy. Our study suggests that M. marshalli might negatively influence fitness of adult female Dall's sheep.

Parasite prevalence, infection intensity and richness in an endangered population, the Atlantic-Gaspésie caribou.

The Atlantic-Gaspésie caribou (Rangifer tarandus caribou) population is a small isolated relict herd considered endangered according to the Canadian Species at Risk Act (SARA). This population has low recruitment and survival rates but the potential role of parasites on individual fitness is unknown. In this context, we explored the parasite status of this population with the aim of 1) assessing the occurrence and intensity of parasite infections and the spatial, temporal and individual variations, 2) quantifying parasite richness and investigating factors such as sex and host body condition that may be associated with this variable and 3) evaluating the effects of parasite infections on survival in the Atlantic-Gaspésie caribou population. We examined fecal samples from 32 animals captured in 2013-2014 for eggs, oocysts and larvae of parasites and detected 7 parasite species: dorsal-spined larvae protostrongylids, presumably Parelaphostrongylus andersoni based on PCR identification of a subset, Nematodirus odocoilei and other unidentified Strongyles, Trichuris sp., Capillaria sp., Moniezia sp. and Eimeria sp. For each caribou, mean parasite species richness was 1.8 ±â€¯1.1 (SD). Sex, body condition, year and capture location did not explain parasite prevalence, intensity of infection or richness except for intensity of infection of Capillaria sp. that was positively influenced by body condition. Parasites did not influence survival although mortality was higher for males than for females. We suggest that the relatively low and common gastrointestinal and protostrongylid parasite infections will not be a short-term threat leading to extinction.

Bacterial Genomics Reveal the Complex Epidemiology of an Emerging Pathogen in Arctic and Boreal Ungulates.

Northern ecosystems are currently experiencing unprecedented ecological change, largely driven by a rapidly changing climate. Pathogen range expansion, and emergence and altered patterns of infectious disease, are increasingly reported in wildlife at high latitudes. Understanding the causes and consequences of shifting pathogen diversity and host-pathogen interactions in these ecosystems is important for wildlife conservation, and for indigenous populations that depend on wildlife. Among the key questions are whether disease events are associated with endemic or recently introduced pathogens, and whether emerging strains are spreading throughout the region. In this study, we used a phylogenomic approach to address these questions of pathogen endemicity and spread for Erysipelothrix rhusiopathiae, an opportunistic multi-host bacterial pathogen associated with recent mortalities in arctic and boreal ungulate populations in North America. We isolated E. rhusiopathiae from carcasses associated with large-scale die-offs of muskoxen in the Canadian Arctic Archipelago, and from contemporaneous mortality events and/or population declines among muskoxen in northwestern Alaska and caribou and moose in western Canada. Bacterial genomic diversity differed markedly among these locations; minimal divergence was present among isolates from muskoxen in the Canadian Arctic, while in caribou and moose populations, strains from highly divergent clades were isolated from the same location, or even from within a single carcass. These results indicate that mortalities among northern ungulates are not associated with a single emerging strain of E. rhusiopathiae, and that alternate hypotheses need to be explored. Our study illustrates the value and limitations of bacterial genomic data for discriminating between ecological hypotheses of disease emergence, and highlights the importance of studying emerging pathogens within the broader context of environmental and host factors.

Onchocerca lupi Nematodes in Dogs Exported from the United States into Canada.

The Onchocerca lupi nematode is an emerging helminth capable of infecting pets and humans. We detected this parasite in 2 dogs that were imported into Canada from the southwestern United States, a region to which this nematode is endemic. We discuss risk for establishment of O. lupi in Canada.

Evaluation of a portable oxygen concentrator to provide fresh gas flow to dogs undergoing anesthesia.

This study evaluated the ability of a portable oxygen concentrator (POC) to provide fresh gas to an anesthetic machine via an Ayre's T-piece or a Bain circuit. Fraction of inspired oxygen (FiO2) was compared at flows of 0.5 to 3.0 L/min. Measured FiO2 was 96% at flow rates ≥ 1 L/min. Mean battery life at 1.0, 2.0, and 3.0 L/min was 4.21 ± 0.45, 2.62 ± 0.37 and 1.5 ± 0.07 hours, respectively. The POC proved to be useful and effective during 2 power outages. The POC was sufficient to prevent rebreathing in 70% of dogs using a T-piece circuit and 20% of dogs with a Bain circuit. A significant negative correlation between inspired CO2 and O2 flow rates was noted. A significant positive correlation between inspired CO2 and ETCO2 was documented. The occurrence of hypercarbia was associated with low O2 flow. Battery back-up was essential during power outages. The POC can be effectively used for delivery of anesthesia.

Évaluation d'un concentrateur d'oxygène portable pour fournir une circulation de gaz frais aux chiens subissant une anesthésie. Cette étude a évalué la capacité d'un concentrateur d'oxygène portable (COP) à fournir du gaz frais à l'aide d'une pièce en T d'Ayre ou d'un circuit de Bain. La fraction d'oxygène inspiré (FiO2) a été comparée à des débits de 0,5 à 3,0 L/min. La FiO2 mesurée était de 96 % à des taux de débit de ≥ 1 L/min. La durée de vie moyenne de la batterie à 1,0, à 2,0 et à 3,0 L/min était de 4,21 ± 0,45, de 2,62 ± 0,37 et 1,5 ± 0,07 heures, respectivement. Le COP s'est avéré utile et efficace durant deux pannes d'électricité. Le COP a été suffisant pour prévenir la réinspiration chez 70 % des chiens en utilisant un circuit de pièce en T et un circuit de Bain chez 20 % des chiens. Une corrélation négative importante entre le CO2 inspiré et les taux de débit d'O2 a été observée. Une corrélation positive importante entre le CO2 inspiré et l' ETCO2 a été documentée. L'occurrence de l'hypercarbie était associée à un faible débit d'O2. Une batterie de secours était essentielle durant les pannes d'électricité. Le COP peut être efficacement utilisé pour fournir de l'anesthésie.(Traduit par Isabelle Vallières).

Patterns of ectoparasitism in North American red squirrels (Tamiasciurus hudsonicus): Sex-biases, seasonality, age, and effects on male body condition.

Within many species, males are often more heavily parasitised than females. Several hypotheses have been proposed to explain this phenomenon, including immunocompetence handicaps, sexual size dimorphism and behavioural differences. Here we set out to test the latter two hypotheses and make inferences about the former by assessing patterns of ectoparasitism across various life-history stages in a population of North American red squirrels (Tamiasciurus hudsonicus). We also conducted an ectoparasite removal experiment to investigate the effects of ectoparasites on male body condition. We found that males were more intensely parasitized than females, but only during the mating period. There was no difference in ectoparasite intensity between male and female juveniles at birth or at emergence, suggesting that ectoparasites do not exploit male red squirrels for longer-range natal dispersal. Male red squirrels in our population were slightly heavier than females, however we did not find any evidence that this dimorphism drives male-biased ectoparasitism. Finally, we could not detect an effect of ectoparasite removal on male body mass. Our results lend support to the hypothesis that ectoparasites exploit their male hosts for transmission and that male red squirrels are important for the transmission dynamics of ectoparasites in this population; however, the mechanisms (i.e., immunocompetence, testosterone) are not known.