Evaluating injuries and illnesses that occurred during the Yukon Quest International sled dog race, 2018-2020.

Introduction: The purpose of this study was to evaluate medical record data from the 2018-2020 Yukon Quest International Sled Dog race to examine injury patterns and risk factors for dogs competing in multi-day ultra-endurance events. Specifically, we summarized injuries and illnesses that resulted in canine athletes being removed ("dropped") from competition, and in orthopedic injuries diagnosed in both dropped and finished dogs. Methods: The records of 989 dogs that started the race were examined, but only records from dogs in teams that went on to finish the race were included, for a total of 711 records. Results and discussion: Three hundred and sixty five dogs (51.3%) were noted to have at least one abnormal finding in their veterinary medical record during the race. Orthopedic injuries were most common, and 291 injuries were ultimately diagnosed in 234 dogs (32.9%). Ultimately, 206 dogs (29%) were dropped from competition, for any reason. The most common reasons for dropping dogs were orthopedic injuries (156 dogs; 188 injuries), gastrointestinal illness (22 dogs), and cardiorespiratory disease (7 dogs). Most orthopedic injuries in dropped dogs occurred in the thoracic limb (n = 121 dogs; 151 injuries). Of those, injuries to the shoulder were most common (n = 77), followed by injuries to the carpus (n = 59), and injury to the pelvic limb (n = 32). Carpal injuries were the most prevalent injury diagnosed in dogs that went on to finish the race (71 of 85 injuries). Carpal injuries were the most prevalent injuries overall in 2018 (51%) and 2019 (52%). In 2020, shoulder injuries were most prevalent (27%), suggesting that trail conditions may have differed between years. The majority of dogs with an orthopedic injury ultimately were removed from competition (156 of 234, or 66.6%), but the likelihood of finishing the race with an injury depended on the type of injury sustained; 71 of 130 dogs (54.6%) with a carpal injury went on to finish the race, whereas only 9 of 86 dogs with a shoulder injury (10.5%) went on to finish. The results of this study can assist mushers and veterinarians in preparing for races, and in decision making during endurance sled dog races.

Effects of hyperthermia and acidosis on mitochondrial production of reactive oxygen species.

Exercise is associated with the development of oxidative stress, but the specific source and mechanism of production of pro-oxidant chemicals during exercise has not been confirmed. We used equine skeletal muscle mitochondria to test the hypothesis that hyperthermia and acidosis affect mitochondrial oxygen consumption and production of reactive oxygen species (ROS). Skeletal muscle biopsies were obtained at rest, after an acute episode of fatiguing exercise, and after a 9-wk conditioning program to increase aerobic fitness. Mitochondrial oxygen consumption and ROS production were measured simultaneously using high-resolution respirometry. Both hyperthermia and acidosis increased nonphosphorylating (LEAK) respiration (5.8× and 3.0×, respectively, P < 0.001) and decreased efficiency of oxidative phosphorylation. The combined effects of hyperthermia and acidosis resulted in large decreases in phosphorylating respiration, further decreasing oxidative phosphorylation efficiency from 97% to 86% (P < 0.01). Increased aerobic fitness reduced the effects of acidosis on LEAK respiration. Hyperthermia increased and acidosis decreased ROS production (2× and 0.23×, respectively, P < 0.001). There was no effect of acute exercise, but an aerobic conditioning program was associated with increased ROS production during both nonphosphorylating and phosphorylating respiration. Hyperthermia increased the ratio of ROS production to O2 consumption during phosphorylating respiration, suggesting that high-temperature impaired transfer of energy through the electron transfer system despite relatively low mitochondrial membrane potential. These data support the role of skeletal muscle mitochondria in the development of exercise-induced oxidative stress, particularly during forms of exercise that result in prolonged hyperthermia without acidosis.NEW & NOTEWORTHY The results of this study provide evidence for the role of mitochondria-derived ROS in the development of systemic oxidative stress during exercise as well as skeletal muscle diseases such as exertional rhabdomyolysis.

Serum myostatin decreases in exercising and aging Alaskan sled dogs, while growth and differentiation factor 15 remains unaltered.

OBJECTIVES: To evaluate the serum concentrations of myostatin and growth and differentiation factor 15 (GDF-15) in Alaskan Husky sled dogs participating in a 350-mile (560-km) race and in an older population, and to examine correlations between changes in serum concentrations and body condition scores (BCSs). ANIMALS: Dogs were recruited from 3 teams of Alaskan Huskies participating in the Alaskan-Yukon Quest sled-dog race and retirees from a research sled-dog colony. PROCEDURES: Serum samples and BCSs were collected prior to racing, midway, and postrace; and in an older cohort (13 to 14 years). Myostatin and GDF-15 concentrations were assessed using commercially available ELISA kits. RESULTS: The median myostatin prerace concentration (9,519 pg/mL) was significantly greater than the mid- and postrace concentrations (7,709 pg/mL and 3,247 pg/mL, respectively). The prerace concentration was also significantly greater than that of the retired sled group dogs at 6,134 pg/mL. GDF-15 median serum concentrations did not change significantly across any racing time point (approx 350 pg/mL) or in the older cohort. No significant correlations were observed between changes in BCS and myostatin or GDF-15 concentrations. CLINICAL RELEVANCE: Serum myostatin decreases dramatically, yet no correlations to loss of BCS could be found. Myostatin signaling may be involved in maintaining hypertrophic signaling during intense exercise. Neither racing distance nor geriatric/retirement status appears to have an effect on serum GDF-15 concentration. Myostatin was less in the older, retired sled dogs compared to the younger racing cohort. Such differences highlight the roles that fitness level and age play regarding myostatin levels.

Successful medical management and rehabilitation of exercise-induced dorsal scapular luxation in an ultramarathon endurance sled dog with magnetic resonance imaging diagnosis of grade II serratus ventralis strain.

Dorsal displacement of the scapula in dogs is rare and often traumatic. This report describes dorsal luxation of the scapula in a sled dog. This case is unique given the injury was sport-related. Magnetic resonance imaging helped direct therapy and monitor healing; and medical management with rehabilitation resulted in full recovery and return to sport. One year after injury, the dog completed both a 482 km and a 1600 km endurance race, placing among the leading teams in the 1600-km race.

Traitement médical réussi d'une luxation scapulaire dorsale aiguë secondaire à la pratique du sport d'endurance chez un chien de traîneau et diagnostic par IRM d'une lésion du m. dentelé ventral. Le déplacement dorsal de la scapula est rare chez le chien et souvent d'origine traumatique. Ce rapport décrit une luxation scapulaire dorsale aiguë chez un chien de traîneau à l'effort. L'intérêt de ce cas tient à sa cause, associé à la pratique de l'activité sportive; à l'analyse des changements en IRM soutenant une thérapie ciblée consistant en un support médical ainsi que d'un programme de rééducation physique, résultant en un rétablissement complet. Un an après cette blessure, le chien termina des courses d'endurance de 482 km et de 1600 km, se classant lors de cette dernière parmi les meilleures équipes de la course.(Traduit par les auteurs).

Butorphanol-Azaperone-Medetomidine for the Immobilization of Captive Caribou ( Rangifer tarandus granti) in Alaska, USA.

A combination of butorphanol-azaperone-medetomidine was used to immobilize four captive caribou ( Rangifer tarandus granti) in Palmer, Alaska, US. The average induction time for this combination was 5:17±2:06 min. Inductions were smooth, and recoveries were excellent. This drug combination may provide an alternative to the use of potent opioids for immobilizing caribou.

Neisseria arctica sp. nov., isolated from nonviable eggs of greater white-fronted geese (Anser albifrons) in Arctic Alaska.

During the summers of 2013 and 2014, isolates of a novel Gram-stain-negative coccus in the genus Neisseriawere obtained from the contents of nonviable greater white-fronted goose (Anseralbifrons) eggs on the Arctic Coastal Plain of Alaska. We used a polyphasic approach to determine whether these isolates represent a novel species. 16S rRNA gene sequences, 23S rRNA gene sequences, and chaperonin 60 gene sequences suggested that these Alaskan isolates are members of a distinct species that is most closely related to Neisseria canis, Neisseriaanimaloris and Neisseriashayeganii. Analysis of the rplF gene additionally showed that the isolates are unique and most closely related to Neisseriaweaveri. Average nucleotide identity of the whole genome sequence of the type strain was between 71.5 and 74.6 % compared to close relatives, further supporting designation as a novel species. Fatty acid methyl ester analysis showed a predominance of C14 : 0, C16 : 0 and C16 : 1ω7c fatty acids. Finally, biochemical characteristics distinguished the isolates from other species of the genus Neisseria. On the basis of these combined data, the isolates are proposed to represent a novel species of the genus Neisseria, with the name Neisseria arctica sp. nov. The type strain is KH1503T (=ATCC TSD-57T=DSM 103136T).

Draft Genome Sequence of a Taxonomically Unique Neisseria Strain Isolated from a Greater White-Fronted Goose (Anser albifrons) Egg on the North Slope of Alaska.

We report here the draft genome sequence of a unique Neisseria strain that was isolated from a greater white-fronted goose (Anser albifrons) egg. The sequencing was performed with an Illumina MiSeq system, and the sequence consists of 275 contigs. The total genome is 2,397,978 bp long and has a G+C content of 46.4%.

Microbial Infections Are Associated with Embryo Mortality in Arctic-Nesting Geese.

To address the role of bacterial infection in hatching failure of wild geese, we monitored embryo development in a breeding population of Greater white-fronted geese (Anser albifrons) on the Arctic Coastal Plain of Alaska. During 2013, we observed mortality of normally developing embryos and collected 36 addled eggs for analysis. We also collected 17 infertile eggs for comparison. Using standard culture methods and gene sequencing to identify bacteria within collected eggs, we identified a potentially novel species of Neisseria in 33 eggs, Macrococcus caseolyticus in 6 eggs, and Streptococcus uberis and Rothia nasimurium in 4 eggs each. We detected seven other bacterial species at lower frequencies. Sequences of the 16S rRNA genes from the Neisseria isolates most closely matched sequences from N. animaloris and N. canis (96 to 97% identity), but phylogenetic analysis suggested substantial genetic differentiation between egg isolates and known Neisseria species. Although definitive sources of the bacteria remain unknown, we detected Neisseria DNA from swabs of eggshells, nest contents, and cloacae of nesting females. To assess the pathogenicity of bacteria identified in contents of addled eggs, we inoculated isolates of Neisseria, Macrococcus, Streptococcus, and Rothia at various concentrations into developing chicken eggs. Seven-day mortality rates varied from 70 to 100%, depending on the bacterial species and inoculation dose. Our results suggest that bacterial infections are a source of embryo mortality in wild geese in the Arctic.

Use of cellulose filter paper to quantify whole-blood mercury in two marine mammals: validation study.

Whole blood (WB) is commonly used to assess mercury (Hg) exposure in mammals, but handling and shipping samples collected in remote areas can be difficult. We describe and validate use of cellulose filter paper (FP) for quantifying WB total Hg concentration. Advantec Nobuto® FP was soaked with bottlenose dolphin (Tursiops truncatus) or harbor seal (Phoca vitulina) WB (collected between March and July 2012), then air dried. Untreated blood-soaked FPs were analyzed or were eluted with phosphate-buffered saline (PBS) and the eluate and PBS-treated FP Hg concentrations were determined. Total Hg from dried blood-soaked FPs, postelution FPs, and PBS-based eluate were compared with total Hg concentrations from WB. Recovery (on a concentration basis) for soaked FP relative to WB was 0.89 ± 0.15, for postelution FP was 0.86 ± 0.13, and for eluate (with a correction factor applied) was 0.96 ± 0.23. Least-squares linear regressions were fit for soaked papers (y = 1.15x, R(2) = 0.97), postelution FPs (y = 1.22x, R(2) = 0.95), and for eluate with a correction factor applied (y = 0.91x+0.03, R(2) = 0.97) as compared with WB. These data show that FP technology can have a valuable role in monitoring blood Hg concentrations in wildlife populations and FPs have the advantage of being easy to use, store, and transport as compared with WB.

Tularemia in Alaska, 1938 - 2010.

Tularemia is a serious, potentially life threatening zoonotic disease. The causative agent, Francisella tularensis, is ubiquitous in the Northern hemisphere, including Alaska, where it was first isolated from a rabbit tick (Haemophysalis leporis-palustris) in 1938. Since then, F. tularensis has been isolated from wildlife and humans throughout the state. Serologic surveys have found measurable antibodies with prevalence ranging from < 1% to 50% and 4% to 18% for selected populations of wildlife species and humans, respectively. We reviewed and summarized known literature on tularemia surveillance in Alaska and summarized the epidemiological information on human cases reported to public health officials. Additionally, available F. tularensis isolates from Alaska were analyzed using canonical SNPs and a multi-locus variable-number tandem repeats (VNTR) analysis (MLVA) system. The results show that both F. t. tularensis and F. t. holarctica are present in Alaska and that subtype A.I, the most virulent type, is responsible for most recently reported human clinical cases in the state.