Comparative Population Genomics of Arctic Sled Dogs Reveals a Deep and Complex History.

Recent evidence demonstrates genomic and morphological continuity in the Arctic ancestral lineage of dogs. Here, we use the Siberian Husky to investigate the genomic legacy of the northeast Eurasian Arctic lineage and model the deep population history using genome-wide single nucleotide polymorphisms. Utilizing ancient dog-calibrated molecular clocks, we found that at least two distinct lineages of Arctic dogs existed in ancient Eurasia at the end of the Pleistocene. This pushes back the origin of sled dogs in the northeast Siberian Arctic with humans likely intentionally selecting dogs to perform different functions and keeping breeding populations that overlap in time and space relatively reproductively isolated. In modern Siberian Huskies, we found significant population structure based on how they are used by humans, recent European breed introgression in about half of the dogs that participate in races, moderate levels of inbreeding, and fewer potentially harmful variants in populations under strong selection for form and function (show, sled show, and racing populations of Siberian Huskies). As the struggle to preserve unique evolutionary lineages while maintaining genetic health intensifies across pedigreed dogs, understanding the genomic history to guide policies and best practices for breed management is crucial to sustain these ancient lineages and their unique evolutionary identity.

Automatic classification of dog barking using deep learning.

Barking and other dog vocalizations have acoustic properties related to emotions, physiological reactions, attitudes, or some particular internal states. In the field of intelligent audio analysis, researchers use methods based on signal processing and machine learning to analyze the digitized acoustic signals' properties and obtain relevant information. The present work describes a method to classify the identity, breed, age, sex, and context associated with each bark. This information can support the decisions of people who regularly interact with animals, such as dog trainers, veterinarians, rescuers, police, people with visual impairment. Our approach uses deep neural networks to generate trained models for each classification task. We worked with 19,643 barks recorded from 113 dogs of different breeds, ages and sexes. Our methodology consists of three stages. First, the pre-processing stage prepares the data and transforms it into the appropriate format for each classification model. Second, the characterization stage evaluates different representation models to identify the most suitable for each task. Third, the classification stage trains each classification model and selects the best hyperparameters. After tuning and training each model, we evaluated its performance. We analyzed the most relevant features extracted from the audio and the most appropriate deep neural network architecture for that feature type. Even if the application of our method is not ready for being used in ethological practice, our evaluation showed an outstanding performance of the proposed method, surpassing previous research results on this topic, providing the basis for further technological development.

The history of Coast Salish "woolly dogs" revealed by ancient genomics and Indigenous Knowledge.

Ancestral Coast Salish societies in the Pacific Northwest kept long-haired "woolly dogs" that were bred and cared for over millennia. However, the dog wool-weaving tradition declined during the 19th century, and the population was lost. In this study, we analyzed genomic and isotopic data from a preserved woolly dog pelt from "Mutton," collected in 1859. Mutton is the only known example of an Indigenous North American dog with dominant precolonial ancestry postdating the onset of settler colonialism. We identified candidate genetic variants potentially linked with their distinct woolly phenotype. We integrated these data with interviews from Coast Salish Elders, Knowledge Keepers, and weavers about shared traditional knowledge and memories surrounding woolly dogs, their importance within Coast Salish societies, and how colonial policies led directly to their disappearance.

​Comparative genomics of Balto, a famous historic dog, captures lost diversity of 1920s sled dogs.

We reconstruct the phenotype of Balto, the heroic sled dog renowned for transporting diphtheria antitoxin to Nome, Alaska, in 1925, using evolutionary constraint estimates from the Zoonomia alignment of 240 mammals and 682 genomes from dogs and wolves of the 21st century. Balto shares just part of his diverse ancestry with the eponymous Siberian husky breed. Balto's genotype predicts a combination of coat features atypical for modern sled dog breeds, and a slightly smaller stature. He had enhanced starch digestion compared with Greenland sled dogs and a compendium of derived homozygous coding variants at constrained positions in genes connected to bone and skin development. We propose that Balto's population of origin, which was less inbred and genetically healthier than that of modern breeds, was adapted to the extreme environment of 1920s Alaska.

Selection for specific behavioural traits does not influence preference of chasing motion and visual strategy in dogs.

Perception of inanimate objects as animate based on motion cues alone seems to be present in phylogenetically distant species, from birth (humans and chicks). However, we do not know whether the species' social and ecological environment has an influence on this phenomenon. Dogs serve as a unique species to investigate whether selection for specific behavioural traits influences animacy perception. We tested purebred companion dogs, and assigned them into two groups based on the type of work they were originally selected for: (1) Chasers, tracking and chasing prey; (2) Retrievers, mark and remember downed game. We displayed isosceles triangles presenting a chasing pattern vs moving independently, in parallel on a screen. We hypothesised that Chasers prefer to look at chasing and Retrievers eventually focus their visual attention on the independent motion. Overall, we did not find a significant difference between groups regarding the looking duration of dogs or the frequency of their gaze alternation between the chasing and independent motions. Thus it seems that selection for specific traits does not influence the perception of animate entities within the species.

Limb development in skeletally-immature large-sized dogs: A radiographic study.

Despite the extreme morphological variability of the canine species, data on limb development are limited and the time windows for the appearance of the limb ossification centres (OCs) reported in veterinary textbooks, considered universally valid for all dogs, are based on dated studies. The aim of this study was to acquire up-to-date information regarding the arm, forearm and leg bone development in skeletally-immature large-sized dogs from 6 weeks to 16 weeks of age. Nine litters of 5 large-sized breeds (Boxer, German Shepherd, Labrador Retriever, Saarloos Wolfdog, White Swiss Shepherd Dog) were included, for a total of 54 dogs, which were subject to radiographic examination on a bi-weekly basis. The appearance of 18 limb OCs was recorded and 14 radiographic measurements were performed; their relationship with age and body weight was investigated and any breed differences were analysed using different statistical non-parametric tests. The number of OCs present was significantly different at 6 and 8 weeks of age between the investigated breeds. The appearance of the OCs occurred earlier in the Saarloos Wolfdog, while the Labrador Retriever was the later breed. In Boxers and Labrador Retrievers, various OCs showed a delayed appearance compared to the data reported in the literature. The number of OCs was strongly and positively correlated to body weight. Breed differences were also observed in the relative increase of the measured OCs and were not limited to dogs of different morphotypes. Statistically significant differences were most frequently observed between Saarloos Wolfdogs and the other breeds. The OCs that showed a greater variability in their development were the olecranon tuber, the patella and the tibial tuberosity. Their increase was more strongly correlated with the dog's age and body weight. Our data strongly suggest that differences in limb development exist in dog breeds of similar size and morphotype.

Czechoslovakian Wolfdog Genomic Divergence from Its Ancestors Canis lupus, German Shepherd Dog, and Different Sheepdogs of European Origin.

This study focused on the genomic differences between the Czechoslovakian wolfdog (CWD) and its ancestors, the Grey wolf (GW) and German Shepherd dog. The Saarloos wolfdog and Belgian Shepherd dog were also included to study the level of GW genetics retained in the genome of domesticated breeds. The dataset consisted of 131 animals and 143,593 single nucleotide polymorphisms (SNPs). The effects of demographic history on the overall genome structure were determined by screening the distribution of the homozygous segments. The genetic variance distributed within and between groups was quantified by genetic distances, the FST index, and discriminant analysis of principal components. Fine-scale population stratification due to specific morphological and behavioural traits was assessed by principal component and factorial analyses. In the CWD, a demographic history effect was manifested mainly in a high genome-wide proportion of short homozygous segments corresponding to a historical load of inbreeding derived from founders. The observed proportion of long homozygous segments indicated that the inbreeding events shaped the CWD genome relatively recently compared to other groups. Even if there was a significant increase in genetic similarity among wolf-like breeds, they were genetically separated from each other. Moreover, this study showed that the CWD genome carries private alleles that are not found in either wolves or other dog breeds analysed in this study.

Multi-omics approach identifies germline regulatory variants associated with hematopoietic malignancies in retriever dog breeds.

Histiocytic sarcoma is an aggressive hematopoietic malignancy of mature tissue histiocytes with a poorly understood etiology in humans. A histologically and clinically similar counterpart affects flat-coated retrievers (FCRs) at unusually high frequency, with 20% developing the lethal disease. The similar clinical presentation combined with the closed population structure of dogs, leading to high genetic homogeneity, makes dogs an excellent model for genetic studies of cancer susceptibility. To determine the genetic risk factors underlying histiocytic sarcoma in FCRs, we conducted multiple genome-wide association studies (GWASs), identifying two loci that confer significant risk on canine chromosomes (CFA) 5 (Pwald = 4.83x10-9) and 19 (Pwald = 2.25x10-7). We subsequently undertook a multi-omics approach that has been largely unexplored in the canine model to interrogate these regions, generating whole genome, transcriptome, and chromatin immunoprecipitation sequencing. These data highlight the PI3K pathway gene PIK3R6 on CFA5, and proximal candidate regulatory variants that are strongly associated with histiocytic sarcoma and predicted to impact transcription factor binding. The CFA5 association colocalizes with susceptibility loci for two hematopoietic malignancies, hemangiosarcoma and B-cell lymphoma, in the closely related golden retriever breed, revealing the risk contribution this single locus makes to multiple hematological cancers. By comparison, the CFA19 locus is unique to the FCR and harbors risk alleles associated with upregulation of TNFAIP6, which itself affects cell migration and metastasis. Together, these loci explain ~35% of disease risk, an exceptionally high value that demonstrates the advantages of domestic dogs for complex trait mapping and genetic studies of cancer susceptibility.

Microsatellite DNA Analysis of Genetic Diversity and Parentage Testing in the Popular Dog Breeds in Poland.

There is growing concern that extreme breed standardization contributes to a reduction of the effective population size and high levels of inbreeding, resulting in the loss of genetic diversity in many breeds. This study examined genetic diversity among eight popular dog breeds in Poland and evaluated the effectiveness of a 21-microsatellite (STR) panel recommended by the International Society for Animal Genetics (ISAG) for parent verification. The following breeds were characterized: German Shepherd, Maltese, Irish Wolfhound, Yorkshire Terrier, Biewer Yorkshire Terrier, Golden Retriever, Labrador Retriever, and French Bulldog. STRUCTURE analysis showed breed distinctiveness among all the dog breeds under study. Reynold's distance ranged between θw = 0.634 and θw = 0.260. The studied breeds showed a medium level of genetic differentiation; the mean number of alleles per locus ranged from 3.4 to 6.6, and the effective number of alleles from 2.1 to 3.5. The mean degree of heterozygosity varied from 49% to 69% and from 47% to 68% for HO and HE, respectively. The population inbreeding coefficient (FIS) indicated an absence of inbreeding in the studied breeds. The average polymorphism information content (PIC) values for most of the breeds were higher than 0.5. The cumulative power of discrimination (PD) for all the markers in all breeds reached high values (close to 1.0), while the probability of identity (PID) was low, ranging between 10-11 and 10-19. The cumulative exclusion probability when the genotypes of one (PE1) and both parents (PE2) are known and showed that the parentage can be confirmed with a probability of 94.92% to 99.95% and 99.78% to 99.9999%, respectively.

Long-read assembly of a Great Dane genome highlights the contribution of GC-rich sequence and mobile elements to canine genomes.

Technological advances have allowed improvements in genome reference sequence assemblies. Here, we combined long- and short-read sequence resources to assemble the genome of a female Great Dane dog. This assembly has improved continuity compared to the existing Boxer-derived (CanFam3.1) reference genome. Annotation of the Great Dane assembly identified 22,182 protein-coding gene models and 7,049 long noncoding RNAs, including 49 protein-coding genes not present in the CanFam3.1 reference. The Great Dane assembly spans the majority of sequence gaps in the CanFam3.1 reference and illustrates that 2,151 gaps overlap the transcription start site of a predicted protein-coding gene. Moreover, a subset of the resolved gaps, which have an 80.95% median GC content, localize to transcription start sites and recombination hotspots more often than expected by chance, suggesting the stable canine recombinational landscape has shaped genome architecture. Alignment of the Great Dane and CanFam3.1 assemblies identified 16,834 deletions and 15,621 insertions, as well as 2,665 deletions and 3,493 insertions located on secondary contigs. These structural variants are dominated by retrotransposon insertion/deletion polymorphisms and include 16,221 dimorphic canine short interspersed elements (SINECs) and 1,121 dimorphic long interspersed element-1 sequences (LINE-1_Cfs). Analysis of sequences flanking the 3' end of LINE-1_Cfs (i.e., LINE-1_Cf 3'-transductions) suggests multiple retrotransposition-competent LINE-1_Cfs segregate among dog populations. Consistent with this conclusion, we demonstrate that a canine LINE-1_Cf element with intact open reading frames can retrotranspose its own RNA and that of a SINEC_Cf consensus sequence in cultured human cells, implicating ongoing retrotransposon activity as a driver of canine genetic variation.

Prevalence and Factors Associated with Ectoparasite Infestations in Dogs from the State of Tabasco, Mexico.

This study was carried out to identify the ectoparasites that infest owned dogs in the state of Tabasco, Mexico. In total, 1,302 dogs were sampled in the 5 ecological regions of Tabasco. The dog owners were surveyed to identify the factors associated with infestations. Ectoparasites were identified using taxonomic keys. Eleven species of ectoparasites were observed. General prevalence was 26.65%. Rhipicephalus sanguineus and Ctenocephalides felis were the most prevalent and abundant ectoparasites. The most important factors associated with ectoparasite infestations in the studied dogs were living outdoors, being a non-purebred, having short hair, being dark-haired, and having a body condition <3. Ectoparasite studies such as the one presented herein generate important information to create control programs focused on decreasing infestations in companion animals and thus the likelihood of zoonotic transmission of pathogens.

Unrecognized difficult airway management during anesthesia in two brachycephalic dogs with narrow cricoid cartilage.

Difficulty in airway management during anesthesia was noted in a 10-year-old, castrated, male Pekingese dog and a 13-year-old male French Bulldog. They showed strong resistance during tracheal tube insertion through the subglottic lumen. Therefore, the airway was secured by using a small endotracheal tube or supraglottic airway device. Computed tomography scan revealed a markedly narrower vertical dimension of the cricoid cartilage compared to that seen in common brachycephalic breeds. Posterior glottis was relatively more accessible for translaryngeal intubation in the present cases. Our findings showed that brachycephalic airway syndrome may be associated with narrow cricoid cartilage. To the best of our knowledge, this is the first clinical case report of airway management during anesthesia in dogs with narrow cricoid cartilage.

R-peak time in clinically healthy dogs with different thoracic conformations.

R-peak time (RPT) is an electrocardiographic parameter that represents the time taken for electrical activation to spread from the endocardium to the epicardium. In human medicine, right ventricular RPT is measured from lead V1 to lead V2, and left ventricular RPT from lead V5 to lead V6. The aim of the present study was to define RPT duration in a group of clinically healthy dogs with different thoracic conformations. Sixty clinically healthy dogs underwent a 12-lead electrocardiogram recorded using a previously described precordial system. The dogs were allocated into three morphologic groups. In the brachymorphic group, the median and 25th-75th percentiles for RPT in V1 were 10.5 ms (10-12 ms); V2, 18 ms (16.5-20 ms); V3, 19 ms (18-22 ms); V4, 20 ms (17-23.5 ms); V5, 21 ms (18.5-24 ms); and V6: 22 ms (18.5-25.5 ms). In the mesomorphic group, RPT in V1 was 16 ms (14-18 ms); V2, 22 ms (20-24 ms); V3, 23 ms (21-25 ms); V4, 23 ms (22-25 ms); V5, 25 ms (23-27 ms); and V6, 28 ms (25-30 ms). In the dolichomorphic group, RPT in V1 was 15 ms (13-17 ms); V2, 29 ms (26-32.5 ms); V3, 30 ms (27-33.5 ms); V4, 29.5 ms (26-35 ms); V5, 30 ms (28-34 ms); and V6, 31.5 ms (28-35 ms). RPT in V1 was significantly shorter than RPT in V2 to V6 in all morphotypes (P < 0.05). In all precordial leads, RPT was significantly different between morphotypes (P < 0.05). These results are in agreement with previous findings in humans and with the observation that V1 reads the right ventricle and V2 to V6 read the left ventricle. These preliminary data provide RPT ranges in clinically healthy dogs of different morphotypes.

Breed-related expression patterns of Ki67, γH2AX, and p21 during ageing in the canine liver.

Cellular senescence is a molecular hallmark of ageing that is associated with multiple pathologies, and DNA damage marker γH2AX, together with cell cycle inhibitor p21, have been used as senescence markers in multiple species including dogs. Idiopathic canine chronic hepatitis has recognised breed-related differences in predisposition and prognosis, but reasons behind this are poorly understood. This retrospective study using archived post mortem tissue aimed to provide insight into liver ageing in 51 microscopically normal canine livers across seven breed categories, including those with and without increased risk of chronic hepatitis. Immunohistochemistry was conducted for γH2AX, p21, and cell proliferation marker Ki67, and the mean number of positive hepatocytes per high power field was determined. All three markers were strongly correlated to each other, but no age-dependent expression was seen in the combined study population. Overall expression levels were low in most dogs, with median values representing less than 1.5% of hepatocytes, but this increased to 20-30% in individual dogs at the upper end of the range. Individual breed differences were noted in two breeds that have increased risk of chronic hepatitis, with English Springer Spaniels having lower expression of Ki67 than other dogs, and Labradors having higher expression of Ki67 and γH2AX than other dogs. These results warrant further investigation in these breeds and highlight a need to validate reliable markers of cellular senescence in dogs.

Unravelling the health status of brachycephalic dogs in the UK using multivariable analysis.

Brachycephalic dog breeds are regularly asserted as being less healthy than non-brachycephalic breeds. Using primary-care veterinary clinical data, this study aimed to identify predispositions and protections in brachycephalic dogs and explore differing inferences between univariable and multivariable results. All disorders during 2016 were extracted from a random sample of 22,333 dogs within the VetCompass Programme from a sampling frame of 955,554 dogs under UK veterinary care in 2016. Univariable and multivariable binary logistic regression modelling explored brachycephaly as a risk factor for each of a series of common disorders. Brachycephalic dogs were younger, lighter and less likely to be neutered than mesocephalic, dolichocephalic and crossbred dogs. Brachycephalic differed to non-brachycephalic types in their odds for 10/30 (33.33%) common disorders. Of these, brachycephalic types were predisposed for eight disorders and were protected for two disorders. Univariable and multivariable analyses generated differing inference for 11/30 (30.67%) disorders. This study provides strong evidence that brachycephalic breeds are generally less healthy than their non-brachycephalic counterparts. Results from studies that report only univariable methods should be treated with extreme caution due to potential confounding effects that have not been accounted for during univariable study design or analysis.

New Guinea highland wild dogs are the original New Guinea singing dogs.

New Guinea singing dogs (NGSD) are identifiable by their namesake vocalizations, which are unlike any other canid population. Their novel behaviors and potential singular origin during dog domestication make them an attractive, but elusive, subject for evolutionary and conservation study. Although once plentiful on the island of New Guinea (NG), they were presumed to currently exist only in captivity. This conclusion was based on the lack of sightings in the lowlands of the island and the concurrent expansion of European- and Asian-derived dogs. We have analyzed the first nuclear genomes from a canid population discovered during a recent expedition to the highlands of NG. The extreme altitude (>4,000 m) of the highland wild dogs' (HWD) observed range and confirmed vocalizations indicate their potential to be a wild NGSD population. Comparison of single-nucleotide polymorphism genotypes shows strong similarity between HWD and the homogeneous captive NGSD, with the HWD showing significantly higher genetic diversity. Admixture analyses and estimation of shared haplotypes with phylogenetically diverse populations also indicates the HWD is a novel population within the distinct evolutionary lineage of Oceanic canids. Taken together, these data indicate the HWD possesses a distinct potential to aid in the conservation of NGSD both in the wild and under human care.

Pharmacokinetics of ceftiofur sodium in Peekapoo dogs following a single intravenous and subcutaneous injection.

The present study aimed to determine the pharmacokinetic profiles of ceftiofur (as measured by ceftiofur and its active metabolites concentrations) in a small-size dog breed, Peekapoo, following a single intravenous or subcutaneous injection of ceftiofur sodium. The study population comprised of five clinically healthy Peekapoo dogs with an average body weight (BW) of 3.4 kg. Each dog received either intravenous or subcutaneous injection, both at 5 mg/kg BW (calculated as pure ceftiofur). Plasma samples were collected at different time points after the administration. Ceftiofur and its active metabolites were extracted from plasma samples, derivatized, and further quantified by high-performance liquid chromatography. The concentrations versus time data were subjected to noncompartmental analysis to obtain the pharmacokinetic parameters. The terminal half-life (t1/2 λz ) was calculated as 7.40 ± 0.79 and 7.91 ± 1.53 hr following intravenous and subcutaneous injections, respectively. After intravenous treatment, the total body clearance (Cl) and volume of distribution at steady-state (VSS ) were determined as 39.91 ± 4.04 ml hr-1  kg-1 and 345.71 ± 28.66 ml/kg, respectively. After subcutaneous injection, the peak concentration (Cmax ; 10.50 ± 0.22 µg/ml) was observed at 3.2 ± 1.1 hr, and the absorption half-life (t1/2 ka ) and absolute bioavailability (F) were calculated as 0.74 ± 0.23 hr and 91.70%±7.34%, respectively. The pharmacokinetic profiles of ceftiofur and its related metabolites demonstrated their quick and excellent absorption after subcutaneous administration, in addition to poor distribution and slow elimination in Peekapoo dogs. Based on the time of concentration above minimum inhibitory concentration (T > MIC) values calculated here, an intravenous or subcutaneous dose at 5 mg/kg of ceftiofur sodium once every 12 hr is predicted to be effective for treating canine bacteria with a MIC value of ≤4.0 µg/ml.

Genomic regions under selection in the feralization of the dingoes.

Dingoes are wild canids living in Australia, originating from domestic dogs. They have lived isolated from both the wild and the domestic ancestor, making them a unique model for studying feralization. Here, we sequence the genomes of 10 dingoes and 2 New Guinea Singing Dogs. Phylogenetic and demographic analyses show that dingoes originate from dogs in southern East Asia, which migrated via Island Southeast Asia to reach Australia around 8300 years ago, and subsequently diverged into a genetically distinct population. Selection analysis identifies 50 positively selected genes enriched in digestion and metabolism, indicating a diet change during feralization of dingoes. Thirteen of these genes have shifted allele frequencies compared to dogs but not compared to wolves. Functional assays show that an A-to-G mutation in ARHGEF7 decreases the endogenous expression, suggesting behavioral adaptations related to the transitions in environment. Our results indicate that the feralization of the dingo induced positive selection on genomic regions correlated to neurodevelopment, metabolism and reproduction, in adaptation to a wild environment.

Fluoroscopic and radiographic assessment of variations in tracheal height during inspiration and expiration in healthy adult small-breed dogs.

The objective of this study was to document tidal variations in tracheal height during normal respiration in 19 healthy adult (> 1 y old) small-breed dogs (< 10 kg) using fluoroscopy and radiography. Each dog underwent tracheal fluoroscopic examination on inspiration and expiration while in a standing position (F-S) and in right lateral recumbency (F-RL), followed by radiographic projections obtained in right lateral recumbency. The percent variation in tracheal height during maximal inspiration and expiration was determined at 3 different locations [cervical region (CR), thoracic inlet (TI), and intrathoracic (IT) region]. When all imaging procedures and sites of measurement were considered, tracheal height varied during physiologic inspiration and expiration from 0% to 21.1%, with a mean of 4.5%. The mean percent variation in tracheal height was not significantly different among imaging modalities (F-S versus F-RL versus radiography) (P = 0.16) or measurement sites (CR versus TI versus IT) (P = 0.89). The body condition score (BCS) (P = 0.96), age (P = 0.95), and breed (P = 0.19) did not significantly influence the mean percent variation in tracheal height. The average variation in tracheal height during maximal physiological inspiration and expiration is small (< 6%) in most healthy adult small-breed dogs as assessed by fluoroscopy and radiography, although tracheal height may vary by as much as 21.1% in some healthy individuals. Inspiratory and expiratory radiographs acquired in right lateral recumbency provide an accurate assessment of tracheal height as an alternative to fluoroscopy.

L'objectif de la présente étude était de documenter les variations de la hauteur de la trachée durant la respiration normale chez 19 chiens adulte en santé (> 1 an) de petites races (< 10 kg) à l'aide de la fluoroscopie et de la radiographie. Chaque chien a été soumis à un examen fluoroscopique de la trachée lors de l'inspiration et de l'expiration alors qu'il était en position debout (F-S) et en décubitus latéral droit (F-RL), suivi d'images radiographiques obtenues en décubitus latéral droit. Le pourcentage de variation de la hauteur de la trachée durant l'inspiration et l'expiration maximales fut déterminé à trois endroits différents [région cervicale (CR), l'entrée thoracique (TI), et la région intrathoracique (IT)]. Lorsque toutes les procédures d'imagerie et les sites de mesure étaient considérés, la hauteur de la trachée variait durant l'inspiration et l'expiration physiologique de 0 % à 21,1 %, avec une moyenne de 4,5 %. Le pourcentage de variation moyen de la hauteur de la trachée n'était pas significativement différent parmi les différentes modalités d'imagerie (F-S versus F-RL versus radiographie) (P = 0,16) ou les sites de mesure (CR versus TI versus IT) (P = 0,89). Le score de condition corporelle (BCS) (P = 0,96), l'âge (P = 0,95), et la race (P = 0,19) n'influençaient pas significativement le pourcentage de variation moyen de la hauteur de la trachée. La variation moyenne de la hauteur de la trachée durant l'inspiration et l'expiration physiologique maximale est petite (< 6 %) chez la plupart des chiens adultes de petites races en santé telle qu'évalué par fluoroscopie et radiographie, bien que la hauteur de la trachée puisse varier jusqu'à 21,1 % chez certains individus en santé. Les radiographies à l'inspiration et à l'expiration obtenues en décubitus latéral droit fournissent une évaluation précise de la hauteur de la trachée comme alternative à la fluoroscopie.(Traduit par Docteur Serge Messier).

Correlation of activity data in normal dogs to distance traveled.

The objective of this study was to explore the mathematical relationships between independent variables (patient morphometrics and treadmill speed) and dependent variables (accelerometer or pedometer output) when evaluating data from accelerometers and pedometers in dogs. Twenty dogs took part in 3 randomized activities, consisting of exercise on a treadmill at 1.0, 1.5, and 2.0 m/s for a total distance of 1 km at each speed. Dogs simultaneously wore both an accelerometer and a pedometer. Statistical analysis used multiple regression models to discover the relationships between independent and dependent variables. A formula was developed to predict the distance traveled by a dog based on its morphometrics and activity monitor output. Shoulder height had stronger correlations to accelerometer and pedometer outputs than other morphometric variables. As shoulder height increased, all accelerometer and pedometer outputs decreased. As treadmill speed increased, both accelerometer and pedometer step counts decreased, while accelerometer activity counts increased. According to a formula derived to predict the total distance traveled using patient shoulder height and accelerometer or pedometer output, pedometer steps were the most accurate predictor of distance traveled. Accelerometer steps were less accurate when using the same model. Accelerometer activity counts did not reveal a meaningful predictive formula. The results of this study indicate that patient morphometrics and treadmill speed (as a measure of intensity) influenced accelerometer and pedometer data. The pedometer data more precisely and accurately estimated the distance traveled based on step counts and patient shoulder height. In normal dogs, accelerometer and pedometer steps may reasonably estimate distance traveled.

L'objectif de la présente étude était d'explorer les relations mathématiques entre des variables indépendantes (données morphométriques du patient et vitesse du tapis d'exercice) et des variables dépendantes (accéléromètre ou données du podomètre) lors de l'évaluation des données provenant d'accéléromètres et de podomètres chez des chiens. Vingt chiens ont pris part à trois activités randomisées, consistant en des exercices sur un tapis roulant à 1,0, 1,5, et 2,0 m/s pour une distance totale de 1 km à chaque vitesse. Les chiens portaient simultanément un accéléromètre et un podomètre. Les analyses statistiques utilisèrent des modèles de régression multiple afin de découvrir les relations entre les variables indépendantes et dépendantes. Une formule fut développée afin de prédire la distance parcourue par un chien sur la base de sa morphométrie et les données des moniteurs d'activité. La hauteur à l'épaule avait la plus forte corrélation aux données de l'accéléromètre et du podomètre comparativement aux autres variables morphométriques. À mesure que la hauteur à l'épaule augmentait, toutes les données de l'accéléromètre et du podomètre diminuaient. Avec l'augmentation de la vitesse du tapis d'exercice, il y eu une diminution du nombre de pas mesuré par l'accéléromètre et le podomètre, alors qu'il y avait une augmentation du compte d'activité de l'accéléromètre. Selon la formule dérivée pour prédire la distance totale parcourue en utilisant la hauteur à l'épaule du patient et les données de l'accéléromètre ou du podomètre, le nombre de pas du podomètre était le prédicteur le plus précis de la distance parcourue. Le nombre de pas avec l'accéléromètre était moins précis en utilisant le même modèle. Le dénombrement des activités par l'accéléromètre n'ont pas permis de déterminer une formule prédictive significative. Les résultats de cette étude indiquent que les données morphométriques des patients et la vitesse du tapis d'exercice (comme mesure d'intensité) influencent les résultats de l'accéléromètre et du podomètre. Les données du podomètre ont estimé avec plus de justesse et de précision la distance parcourue en se basant sur le nombre de pas et la hauteur à l'épaule du patient. Chez les chiens normaux, le nombre de pas mesuré par un accéléromètre et un podomètre peut raisonnablement estimer la distance parcourue.(Traduit par Docteur Serge Messier).