Body-weight changes during growth in puppies of different breeds

Genome-Wide Characterization of Somatic Mutation Patterns in Cloned Dogs Reveals Implications for Neuronal Function, Tumorigenesis, and Aging

Studies on somatic mutations in cloned animals have revealed slight genetic variances between clones and their originals, but have yet to identify the precise effects of these differences within the organism. Somatic mutations contribute to aging and are implicated in tumor development and other age-related diseases. Thus, we compared whole genome sequencing data from an original dog with that of cloned dogs, identifying candidate somatic mutations that were disproportionately located within genes previously implicated in aging. The substitutional signature of cloning-specific somatic mutations mirrored the uniform distribution characteristic of the signature associated with human aging. Further analysis of genes revealed significant enrichment of traits associated with body size as well as the molecular mechanisms underlying neuronal function and tumorigenesis. Overall, the somatic mutations found in cloned dogs may indicate a conserved mechanism driving aging across species and a broad spectrum of pathway alterations.

Prebiotic fiber blend supports growth and development and favorable digestive health in puppies

Introduction

A healthy gastrointestinal (GI) microbiome has been shown to be essential for proper nutrient absorption and metabolism, maintenance of intestinal epithelial integrity and osmolarity, gut immunomodulation, and overall health. One of the most effective ways to promote a healthy GI microbiome is through dietary interventions, such as the addition of prebiotics. Prebiotics are substrates that are selectively utilized by the host GI microbiome through fermentation to confer a health benefit. However, research on prebiotics in companion animals is limited, especially in growing animals. Thus, this study was conducted to assess the effects of a novel prebiotic fiber blend on key parameters related to intestinal health and growth in puppies.

Methods

Twenty-two puppies at least 4 months of age but not older than 10 months were fed a commercially available dry food during a prefeed period, and then fed a similarly formulated test food with the addition of the prebiotic fiber blend for a minimum of 90 days. Serum and fecal samples were collected at the end of the prefeed period and throughout the test period.

Results

Puppies fed the test food grew as expected for puppies of this age. Complete blood count and serum chemistry analyses were clinically normal for all animals. Fecal score increased linearly, fecal moisture decreased linearly, and pH exhibited a cubic trend throughout the study duration. There was a linear increase in short-chain fatty acids throughout the study, which is associated with favorable digestive and overall health. The inflammatory cytokine interleukin-7 decreased linearly and interleukin-18 trended towards linear decrease.

Conclusion

This study showed that puppies continued to grow and develop normally, and experienced serum and stool characteristics indicative of improved GI health when fed a growth food fortified with a novel prebiotic fiber blend. Furthermore, these results contribute to the overall understanding of the effects of prebiotics on the GI health of growing companion animals.

Factors related to longevity and mortality of dogs in Italy

Besides its translational value, an improved understanding of dog longevity and mortality is necessary to guide health management decisions, breed selection, and improve dog welfare. In order to analyse the lifespan of dogs in Italy, identify the most common causes of death, and evaluate possible risk factors, anonymised medical records were collected from 9 veterinary teaching hospitals and 2 public health institutions. Data regarding breed, sex, neuter status, age, diagnosis, and mechanism of death were retrieved. Cause of death (COD) was classified by pathophysiologic process (PP) and organ system (OS). Of the 4957 dogs that died between 2004 and 2020 included in the study, 2920 (59.0%) were purebred, 2293 (46.2%) were female, 3005 (60.6%) were intact, 2883 (58.2%) were euthanised. Overall median longevity was 10.0 years. Median longevity was significantly longer for crossbreds, females, neutered dogs, and small-sized breeds. The breeds with the highest median age at death were the Yorkshire terrier, English cocker spaniel, West Highland white terrier, Italian volpino, and Shih Tzu, whilst the American bulldog, English bulldog, American pit bull terrier, Bernese mountain dog and the Maremma and the Abruzzes sheepdog had the lowest median age at death. The most frequent COD by PP was neoplasia (34.0%), which occurred more frequently in large breeds, namely German shepherd, Labrador retriever and Boxer. Degenerative diseases mostly affected small-sized dogs like Miniature pinscher and Dachshund. Regarding the OS involved, diseases of the renal/urinary system were most frequently responsible for COD (15.0%), prevalently degenerative and inflammatory/infectious. Substantial variation in median longevity according to causes of death by PP and OS was observed. These data are relevant for breeders, veterinary practitioners, and owners, to assist breed selection, facilitate early diagnosis, guide choice when purchasing a purebred dog and making health management decisions, and ultimately improve dog welfare.

Differential behavioral aging trajectories according to body size, expected lifespan, and head shape in dogs

The twofold life expectancy difference between dog breeds predicts differential behavioral and cognitive aging patterns between short- and long-lived dogs. To investigate this prediction, we conducted a cross-sectional analysis using survey data from over 15,000 dogs. We examined the effect of expected lifespan and three related factors (body size, head shape, and purebred status) on the age trajectory of various behavioral characteristics and the prevalence of canine cognitive dysfunction (CCD). Our findings reveal that, although age-related decline in most behavioral characteristics began around 10.5 years of age, the proportion of dogs considered "old" by their owners began to increase uniformly around 6 years of age. From the investigated factors, only body size had a systematic, although not gradual, impact on the aging trajectories of all behavioral characteristics. Dogs weighing over 30 kg exhibited an earlier onset of decline by 2-3 years and a slower rate of decline compared to smaller dogs, probably as a byproduct of their faster age-related physical decline. Larger sized dogs also showed a lower prevalence of CCD risk in their oldest age group, whereas smaller-sized dogs, dolichocephalic breeds, and purebreds had a higher CCD risk prevalence. The identification of differential behavioral and cognitive aging trajectories across dog groups, and the observed associations between body size and the onset, rate, and degree of cognitive decline in dogs have significant translational implications for human aging research, providing valuable insights into the interplay between morphology, physiological ageing, and cognitive decline, and unravelling the trade-off between longevity and relative healthspan.

Nutrition and Aging in Dogs and Cats

Aging is often associated with chronic inflammation and declining health. Both veterinarians and owners of aging dogs and cats are interested in nutritional solutions and strategies to prevent signs of age-related disease, increase longevity, and improve quality of life. Physiological decreases in muscle mass, decreased immunity, and a decrease in sense acuity are some of the changes often seen in otherwise healthy senior pets; however, there may also be an increase in risk for pathologies such as renal, cardiovascular, musculoskeletal, and neoplastic diseases. Aging may also lead to cognitive decline and even cognitive dysfunction. Some nutritional strategies that may be helpful with the prevention and treatment of age-related diseases include supplementation with ω3 polyunsaturated fatty acids and antioxidant nutrients that can help modulate inflammation and benefit osteoarthritis, renal disease, cancer, and more. Supplementation with medium-chain triglycerides shows promise in the treatment of canine cognitive dysfunction as these may be metabolized to ketone bodies that are utilized as an alternative energy source for the central nervous system. Additionally, a high intake of dietary phosphorus in soluble and bioavailable forms can lead to renal disease, which is of greater concern in senior pets. There are no published guidelines for nutritional requirements specific to senior pets and as a result, products marketed for senior dogs and cats are highly variable.

Birth weight, puppies' growth and health with limited-ingredient novel protein diet vs standard diet in late pregnancy

Great attention has been given in the last years to the protein source of dog food, and commercial limited-ingredient diets with a single protein are available also for late pregnancy. This work compared the effect of a fish-based limited ingredient diet (LID), and of a standard mixed-protein diet (Mixed), fed to the bitches from the last three weeks of pregnancy and to the puppies at weaning, on birth weight, growth and health of the puppies. From a breeder's records, the weight of 22 Lagotto Romagnolo (LR) and 10 Appenzeller Cattle Dog (ACD) bitches on the day of mating, and of their 199 puppies, were extracted. The effect of diet on puppies' weight on day 0, 6, 30 and 60 was analyzed, considering litter size and sex. The analyses were repeated on puppies' weights normalized on the relative dam's non-pregnant bodyweight. Birth weight was available for 146 puppies, 82 LR and 64 ACD. Median birth weight of LR puppies was 287.5 g (170-400 g); sex ratio was 1.11 (males/females, N = 80). Median birth weight of ACD puppies was 390 g (240-525 g); sex ratio 1.15 (males/females, N = 58). Diet did not significantly affect birth weight in both breeds; however, it showed a significant effect on normalized birth weights (LR, P = 0.016; ACD, P = 0.034), with higher values for LID. At day 30, ACD puppies showed significantly higher weights with the Mixed diet (P = 0.002), and, at day 60, diet significantly affected the normalized weight in both breeds (LR, P = 0.019; ACD, P = 0.001), with higher values for the Mixed type. LID may help the dam to invest the energy in the growth of her litter, however, the same diet resulted in lower puppies' weights around weaning, compared to the Mixed diet. Although our results should be confirmed with larger numbers of animals and more breeds, they set some points worth to be further investigated. The choice of a limited-ingredient single-protein diet can affect litter weight and weight at weaning. Whether, administered to dams and puppies, it can prevent later pathologies, like chronic gastrointestinal diseases or food allergies, is a field of research deserving full attention.

Neonatal-Maternal Bodyweight Ratio at Birth: An Indicator for First-Week Survival Prognosis in Canine Newborns

Objectives. In dogs, neonatal bodyweight (NBW) varies at birth. Size-specific reference values for NBW are essential to correctly manage newborns. The present study aimed to define a new tool to evaluate NBW that could be routinely applied in canine neonatology, promptly identifying puppies requiring more care. Methods. The records of 89 litters were retrospectively evaluated. Data were grouped according to maternal bodyweight (MBW) in five categories: toy (≤5 kg), small (5.1-9.9 kg), medium (10-24.9 kg), large (25-39.9 kg), and giant (≥40 kg) dogs. At birth, the NBW of 412 puppies, alongside their litter size (LS) and gender (G), were recorded. Neonatal mortality within the first week was considered. The influence of MBW, LS, and G on NBW and the effect of NBW on the 1-week outcome were evaluated using ANOVA (p < 0.05). The ratio between NBW and MBW expressed as a percentage (N-MBW%), was assessed for each puppy. Through Receiver-Operating Characteristic (ROC) curves, N-MBW% thresholds between puppies alive or dead at one week of age were calculated in each group. Results. The LS was different among groups, except for small vs. medium dogs. In small litters, N-MBW% was lower in medium-, large- and giant-sized dogs than in toy and small dogs. In medium and large litters, N-MBW% differed among the five groups. Male and female N-MBW% differed among the five groups. Only in large and giant sizes did LS affect N-MBW%, which was lower in a large LS. The N-MBW% was higher in healthy puppies than in those who died within one week. The ROC-derived N-MBW% thresholds were as follows: 4.5% in toy-, 3.2% in small-, 1.5% in medium-, 1.2% in large-, and 1% in giant dogs. Clinical significance. The ROC-derived N-MBW% thresholds can be used to cautiously identify puppies at increased risk for one-week mortality and may be helpful in clinical practice, representing a suitable parameter to give a prognosis on 1-week survival immediately at birth.

The relative benefits for environmental sustainability of vegan diets for dogs, cats and people

Environmental impacts of the livestock sector are proportional to consumption levels. To assess the relative consumption of livestock animals within the diets of dogs, cats and people, this study examined their dietary energy needs within the US in 2020, and globally in 2018. Also studied were US pet food ingredients, and environmental sustainability indicators for plant- and animal-based foods consumed globally. Relative consumptions of average livestock animals were: US: dogs- 17.7%, cats- 2.3%, humans- 80.0%; and globally: dogs- 7.7%, cats- 1.2%, humans- 91.1%. Full transition to nutritionally-sound vegan diets would spare from slaughter the following numbers of terrestrial livestock animals annually (billions): US: dogs- 1.7, cats- 0.2, humans- 7.8, and globally: dogs- 6.0, cats- 0.9, humans- 71.3, as well as billions of aquatic animals in all dietary groups. Very large impact reductions were also associated with land and water use, emissions of greenhouse gases (GHGs), acidifying and eutrophifying gases, and biocide use, in all dietary groups. If implemented globally, nutritionally-sound vegan diets would free up land larger than the following nations: dogs-Saudi Arabia or Mexico, cats-Japan or Germany, humans-Russia-the world's largest country-combined with India. Such diets would save freshwater volumes greater than all renewable freshwater in the following nations: dogs-Denmark, cats-Jordan, humans-Cuba. Such diets would reduce GHGs by amounts greater than all GHG emissions from following nations: dogs-South Africa or the UK, cats-Israel or New Zealand, humans-India or the entire EU. The numbers of additional people who could be fed using food energy savings associated with vegan diets exceeded the 2018 human populations of the following nations: dogs-the entire European Union, cats-France or the UK, humans-every single nation or collective region on Earth, as defined by the World Bank. All of these estimates are conservative.

Scientific and technical assistance on welfare aspects related to housing and health of cats and dogs in commercial breeding establishments

This Scientific Report addresses a mandate from the European Commission according to Article 31 of Regulation (EC) No 178/2002 on the welfare of cats and dogs in commercial breeding establishments kept for sport, hunting and companion purposes. The aim was to scrutinise recent recommendations made by the EU Platform on Animal Welfare Voluntary Initiative on measures to assist the preparation of policy options for the legal framework of commercial breeding of cats and dogs. Specifically, the main question addressed was if there is scientific evidence to support the measures for protection of cats and dogs in commercial breeding related to housing, health considerations and painful procedures. Three judgements were carried out based on scientific literature reviews and, where possible a review of national regulations. The first judgement addressed housing and included: type of accommodation, outdoor access, exercise, social behaviour, housing temperature and light requirements. The second judgement addressed health and included: age at first and last breeding, and breeding frequency. Judgement 3 addressed painful procedures (mutilations or convenience surgeries) and included: ear cropping, tail docking and vocal cord resections in dogs and declawing in cats. For each of these judgements, considerations were provided indicating where scientific literature is available to support recommendations on providing or avoiding specific housing, health or painful surgical interventions. Areas where evidence is lacking are indicated.

A questionnaire-based investigation of the swimming puppy syndrome: 115 dogs

Swimming Puppy Syndrome (SPS) is a benign reversible condition of unknown etiology in multiple dog breeds. Affected dogs show laterally abducted limbs and are unable to stand and walk on their own. The current knowledge of this condition derives from few case reports or small case series. Therefore, the aim of this study was to collect data on the clinical course from a large cohort of dogs with SPS with an online questionnaire supported by video footage. Potential risk factors were compared between 110 litters with SPS and 103 unaffected litters. SPS was reported in 115 dogs from 48 different breeds comprising a wide range of small, middle, and large breeds. Litters with SPS were significantly smaller than unaffected litters. Cesarean sections were reported more frequently in affected litters, but the overall rate of reported birth complications did not differ significantly from unaffected litters. Most puppies were able to stand and walk at a median age of 4.5 weeks (up to 12 weeks) and clinical signs resolved at a median age of six weeks (up to 12 weeks). Puppies from large breeds showed faster recovery than puppies from medium and small breeds. Occasionally, residual deficits were reported and only three dogs failed to recover. A clustering of SPS occurred in closely related litters in four kennels of four different dog breeds (Greater Swiss Mountain Dog, Golden Retriever, Miniature Bull Terrier, Norwich Terrier). The study shows the benign clinical course of SPS in a large cohort of puppies from multiple dog breeds. Potential risk factors including reports on birth complications, size and muscle mass compared to littermates and diet of the dam during pregnany were evaluated and no influence on the occurrence of SPS was identified.

Morphometrical and Immunohistochemical Evaluation of Kidney as an Indirect Parameter to Estimate Age in Puppies in Veterinary Forensic Pathology

Estimation of age represents a central focus in the veterinary forensic pathology field. Currently, the visual examination of the dentition and the skeletal age are the main methods to estimate the age of puppies. Nevertheless, these methods are affected by a broad range of variables. In contrast, the kidney is characterized by a specific postnatal development. In human glomerulogenesis, fetal mesangial cells change their immunohistochemical phenotypes with maturation. Therefore, we hypothesized that histological and immunohistochemical examinations of the kidney can be used together as an indirect parameter for age determination in puppies' cadavers. Forty-five puppies' cadavers were divided into five groups defined by age (Group A= 0-15 days, Group B = 16-45 days, Group C = 46-85 days, Group D = 86-105 days, Group E= 105-365 days). For each case, kidney samples were collected and processed for histopathological (for morphometrical study of the glomerulus) and immunohistochemical (for the immunolocalization of the α-SMA protein) studies. Morphometrical study allowed us to observe statistical differences in the mean glomerulus numbers per field among assessed groups. Similarly, immunohistochemical examination showed differences in SMA expression among groups. Our findings suggest a potential use of kidney morphometrical and immunohistochemical examinations together as an indirect parameter to assess the age of illegally imported puppies.

Success of orthodontic treatment of linguoverted mandibular canine teeth using a direct inclined plane appliance

This study evaluated the success rate of orthodontic treatment of linguoverted mandibular canines in dogs using a directly applied inclined plane device. Medical records were retrospectively evaluated at 11 veterinary dental specialty hospitals from 1999 to 2021. Malocclusion classes included 41.7% in class 1, 47.2% in class 2, 6.9% in class 3, and 4.2% in class 4. The severity of linguoversion was mild in 7.6% of teeth, moderate in 33.9%, and severe in 58.5%. There was complete resolution of linguoversion in 71.2% of teeth, functional resolution in 25.4%, and failure in 3.4%. The median treatment time was 42 (11-174) days. Adjuvant orthodontic treatments were performed at the same time as the inclined plane in 45.7% of teeth, including active force orthodontics, extractions of non-strategic teeth, gingivectomy, and odontoplasty. While the inclined plane was in place, 31.4% of dogs required an anesthetized appliance adjustment, and at the time of appliance removal, complications occurred in 19.4% of dogs. Of the teeth that had initial resolution, 14.4% had rebound movement that required additional treatment. This study supports the idea that an acrylic inclined plane is a good treatment option for linguoverted mandibular canines, with a 96.6% success rate within a median of 6 weeks. Yet, orthodontic retention may be necessary in these cases to avoid the need for additional therapies.

Characterization of FCI (Fédération Cynologique Internationale) Grades for Hip Dysplasia in Five Dog Breeds

The aim of this retrospective study was to verify whether the radiographic morphologic differences detected within the first three grades of hip dysplasia (A, B, C) of each of the five selected breeds and within the same breeds were statistically significant enough to require a breed-specific evaluation. A total of 422 technical evaluation forms of hip dysplasia (HD) in Labrador Retrievers, Golden Retrievers, Rottweilers, Bernese Mountain dogs, and German Shepherd dogs were obtained from the Fédération Cynologique Internationale (FCI) archive. The data were evaluated using a descriptive statistical analysis. In Labrador Retrievers, the craniolateral acetabular rim and femoral head position were already altered in unaffected dogs; however, within the various FCI grades, the most severe changes involved the conformation of the femoral neck. All the radiographic parameters of the Golden Retriever hips changed progressively and evenly. Significant radiographic changes between FCI grades were found in the German Shepherd dogs, and the alterations involving the acetabulum were more severe and appeared earlier than in the femoral head and neck. In the Bernese Mountain dogs, the most severe alterations were in the position of the femoral head and joint space while the femoral head and neck showed no significant progression between grades. All the radiographic parameters of non-dysplastic Rottweilers were normal; however, the progression of the primary signs was similar to the other breeds, although with lower severity. In conclusion, no significant prevalence of the radiographic features was observed for any specific breed. However, significant individual breed variations in the primary radiographic parameters were found between dogs with and without dysplasia which could be useful for better understanding the consequences of biomechanical differences between breeds.

Age estimation of puppies based on the radiographically assessed development of ossification centres in the carpal and metacarpal regions

BACKGROUND

The need for proper age determination in puppies has increased enormously due to the growing illegal trade in puppies that are too young to be removed from the litter or too young to have been properly vaccinated against rabies.

METHODS

Dorsopalmar and mediolateral radiographs of the (meta)carpal region, either taken from puppy cadavers or from the Faculty's patient database, were studied in a cross-sectional study of 252 puppies of various sizes, aged 6-212 days. The appearance and development of ossification centres as a function of age in five regions of interest in the (meta)carpal region were scored using a two- to six-step scoring system based on shape and delineation.

RESULTS

A positive correlation with age was found for all investigated regions. Intra- and interrater agreement between two observers was excellent, except for the distal epiphyses of the metacarpal bones. Postnatal ossification started after the second week of life with the carpal bones, closely followed by the radial trochlea. All ossification centres were present in all puppies from 84 days, except for the sesamoid bone in the tendon of the long abductor muscle of the first digit. Timing of appearance differed significantly between different sized breeds. There were no significant differences between the sexes.

LIMITATIONS

Age distribution was not balanced for all breed size classes.

CONCLUSIONS

The radiographic timing of the appearance and development of ossification centres in the carpal region is a promising method for age estimation in puppies.

Exploration of body weight in 115 000 young adult dogs of 72 breeds

High body weight (BW), due to large size or excess body fat, has been associated with developmental and metabolic alterations, and degenerative diseases in dogs. Study objectives were to determine mean BW in young adult dogs of different breeds, including changes over a 10-year period. Body weight data from the official Swedish hip dysplasia screening program were used, including data from dogs screened at 1-2.5 years of age, in breeds with ≥ 15 individual observations/year during 2007-2016. Mean BW per breed and sex was established from 114 568 dogs representing 72 breeds. Estimates of breed BW showed significant change in 33 (45%) breeds over the 10-year period. Body weight increased in five breeds (2-14% change) and decreased in 26 breeds (1-8% change). In two breeds, BW increased in male and decreased in female dogs. This observational study provides extensive breed BW data on young adult dogs. The change in breed BW, noted in almost half of the breeds, could be due to changes either in size or in body fat mass. In certain breeds, the change in BW over time might have an impact on overall health. Studies with simultaneous evaluation of BW and body condition over time are warranted.

Environmental risk factors in puppies and kittens for developing chronic disorders in adulthood: A call for research on developmental programming

Many dogs and cats are affected by chronic diseases that significantly impact their health and welfare and relationships with humans. Some of these diseases can be challenging to treat, and a better understanding of early-life risk factors for diseases occurring in adulthood is key to improving preventive veterinary care and husbandry practices. This article reviews early-life risk factors for obesity and chronic enteropathy, and for chronic behavioral problems, which can also be intractable with life-changing consequences. Aspects of early life in puppies and kittens that can impact the risk of adult disorders include maternal nutrition, establishment of the gut microbiome, maternal behavior, weaning, nutrition during growth, growth rate, socialization with conspecifics and humans, rehoming and neutering. Despite evidence in some species that the disorders reviewed here reflect the developmental origins of health and disease (DOHaD), developmental programming has rarely been studied in dogs and cats. Priorities and strategies to increase knowledge of early-life risk factors and DOHaD in dogs and cats are discussed. Critical windows of development are proposed: preconception, gestation, the suckling period, early growth pre-neutering or pre-puberty, and growth post-neutering or post-puberty to adult size, the durations of which depend upon species and breed. Challenges to DOHaD research in these species include a large number of breeds with wide genetic and phenotypic variability, and the existence of many mixed-breed individuals. Moreover, difficulties in conducting prospective lifelong cohort studies are exacerbated by discontinuity in pet husbandry between breeders and subsequent owners, and by the dispersed nature of pet ownership.

Growth charts for small sample sizes using unsupervised clustering: Application to canine early growth

Breed-specific growth curves (GCs) are needed for neonatal puppies, but breed-specific data may be insufficient. We investigated an unsupervised clustering methodology for modeling GCs by augmenting breed-specific data with data from breeds having similar growth profiles. Puppy breeds were grouped by median growth profiles (bodyweights between birth and Day 20) using hierarchical clustering on principal components. Median bodyweights for breeds in a cluster were centered to that cluster’s median and used to model cluster GCs by Generalized Additive Models for Location, Shape and Scale. These were centered back to breed growth profiles to produce cluster-scale breed GCs. The accuracy of breed-scale GCs modeled with breed-specific data only and cluster-scale breed GCs were compared when modeled from diminishing sample sizes. A complete dataset of Labrador Retriever bodyweights (birth to Day 20) was split into training (410 puppies) and test (460 puppies) datasets. Cluster-scale breed and breed-scale GCs were modelled from defined sample sizes from the training dataset. Quality criteria were the percentages of observed data in the test dataset outside the target growth centiles of simulations. Accuracy of cluster-scale breed GCs remained consistently high down to sampling sizes of three. They slightly overestimated breed variability, but centile curves were smooth and consistent with breed-scale GCs modeled from the complete Labrador Retriever dataset. At sampling sizes ≤ 20, the quality of breed-scale GCs reduced notably. In conclusion, GCs for neonatal puppies generated using a breed-cluster hybrid methodology can be more satisfactory than GCs at purely the breed level when sample sizes are small.

The Long-Term Influence of Puppy Acquisition on Physical Activity: Results of a 3-Year, Longitudinal, Pilot Study

Dog ownership has been associated with increased levels of physical activity (PA), including increases in total PA and walking time in some but not in all studies. These earlier studies did not consider puppy acquisition, in particular, and were limited to a maximum of 10 months duration. The purpose of the current pilot study was, therefore, to analyze long-term changes in participants’ PA behavior after puppy acquisition. Participants who acquired a puppy from one of nine preselected breeds differing in size and energy level were included. PA was assessed at baseline and 6, 12, 24 and 36 months after puppy acquisition using an online questionnaire. Participants, who were initially included, did not differ in their PA at baseline (n = 38). In the group that completed the trial (n = 11) total PA, leisure time walking, total dog-related PA, and total dog walking increased within the first two years and decreased while remaining above baseline values during the last year, coinciding with the COVID-19 pandemic. Non-dog-related PA did not change over time. We conclude that the acquisition of a puppy increases PA and thus, could have a long-lasting positive effect on physical health.

Gut microbiota development in the growing dog: A dynamic process influenced by maternal, environmental and host factors

Microorganisms of the gastrointestinal tract play a crucial role in the health, metabolism and development of their host by modulating vital functions such as digestion, production of key metabolites or stimulation of the immune system. This review aims to provide an overview on the current knowledge of factors shaping the gut microbiota of young dogs. The composition of the gut microbiota is modulated by many intrinsic (i.e., age, physiology, pathology) and extrinsic factors (i.e., nutrition, environment, medication) which can cause both beneficial and harmful effects depending on the nature of the changes. The composition of the gut microbiota is quickly evolving during the early development of the dog, and some crucial bacteria, mostly anaerobic, progressively colonize the gut before the puppy reaches adulthood. Those bacterial communities are of paramount importance for the host health, with disturbance in their composition potentially leading to altered metabolic states such as acute diarrhea or inflammatory bowel disease. While many studies focused on the microbiota of young children, there is still a lack of knowledge concerning the development of gut microbiota in puppies. Understanding this early evolution is becoming a key aspect to improve dogs' short and long-term health and wellbeing.

Development and initial validation of a dog quality of life instrument

The increasing attention for the dog-owner relationship combined with advances in nutrition and veterinary care have made wellbeing a focal point for dog owners, veterinarians, and dog product and service providers. While canine wellbeing can be quantified by survey-based quality of life instruments like those used in human healthcare, there are currently few instruments available that can do this reliably and at scale. Here we report the development and initial validation of a canine quality of life instrument specifically designed to quantify wellbeing in the general dog population. The instrument is based on a simple 32-question survey and includes 5 daytime domains (energetic, mobile, relaxed, happy, sociable) and 3 mealtime domains (relaxed, interested and satisfied). It captures specific health-related aspects as well as more general wellbeing aspects and, in an initial sample of 2813 dogs, already provides useful insights on canine wellbeing. We believe that data collection at scale with this instrument will help bring optimal wellbeing to the dogs we care for.

Owner-misperception of canine body condition reduces after using a five-point body condition score chart: A study of 95 large-sized purebred dogs

The body condition score (BCS) is a popular method used to assess the body condition of dogs. However, owner-misperception of canine body condition has shown to persist even after being guided by a BCS chart. We compared the BCS assessments performed by the owners of 95 large-sized, purebred dogs without and with the guidance of a five-point BCS chart. Initially, only 23/95 dog owners accurately assessed the BCS of their dogs and the correct assessments significantly increased after being guided by a BCS chart (50/95, p < 0.001). In addition, initially there was only a poor agreement between the owners and the primary investigator (κ = 0.14) that improved significantly after the owners were guided by a BCS chart (κ = 0.6). The present findings suggest that BCS charts are useful for reducing owner-misperception on canine body condition in large-sized, purebred dogs.

Age estimation in young dogs by radiographic assessment of the canine pulp cavity/tooth width ratio

Age estimation in adult dogs can be performed by the radiographic measurement of the tooth pulp cavity, but the technique has hardly been described. In this study, the application of measuring pulp/tooth width ratios (P/T ratios) of the maxillary canine teeth was investigated. Pulp and tooth widths were measured at two locations on 166 maxillary canine teeth of the heads of 84 dog cadavers, using digital extraoral lateral oblique open mouth radiographs. The dogs belonged to different breeds and sexes and had a known age between 194 and 1907 days (approximately 6 months - 5 years). Both at the cemento-enamel junction (CE) and the half-height of the tooth, a comparable non-linear regression with age was demonstrated. Measuring at the CE location was less hindered by wear or superimposition. No statistically significant difference according to sex and breed size and no clinically significant difference according to skull type was found. The highest predictable capacity was found in the youngest dogs until the age of 448 days, of which 84.4% of the canine teeth had a P/T ratio above 0.39. Our results demonstrate that measuring P/T ratios of canine teeth can be used in practice to assign dogs to age categories, with the highest accuracy in young adult dogs.

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.

Energy Requirements for Growth in the Norfolk Terrier

An appropriate energy intake for healthy growth can reduce the risk of obesity and co-morbidities, such as orthopaedic diseases. The 2006 National Research Council (NRC) universal equation calculates the energy requirement of growing dogs based on predicted adult body weight, but evidence suggests a revision may be required. This study investigates the energy requirements of seventeen Norfolk terrier puppies over their first year (10 to 52 weeks). Puppies were individually fed complete and balanced diets in amounts to maintain an optimal body condition score (BCS), recording intake daily and body weight and BCS weekly. To monitor health a veterinary examination, haematology and plasma biochemistry and serum measures of bone turnover were undertaken every 12 weeks. Skeletal development was assessed using dual-energy X-ray absorptiometry (26 and 52 weeks). Puppies were clinically healthy with normal skeletal development and healthy growth throughout. The energy intake to achieve this was significantly lower than that predicted by the NRC (2006) equation at all time points, with largest mean difference of 285 kJ/kg^0.75 per day at 10 weeks. If fed according to the NRC 2006 equation, dogs would have been in positive energy balance, possibly leading to obesity. These data support a revision to the NRC (2006) equation.

The sesamoid bone in the long abductor muscle tendon of the first digit in the dog

The sesamoid bone in the tendon of the m. abductor digiti primi longus is considered present in most dog breeds and is described to be radiologically detectable at the level of the carpus from the age of 4 months. However, an extensive investigation of this sesamoid bone has not been conducted before. The aim of this study was therefore to determine its prevalence in different dog breeds, to describe its histological development, and to determine the age at which it becomes radiologically visible. The prevalence of the sesamoid bone was assessed on radiographic images of the carpus or by dissection of the carpal region in 743 adult dogs of 115 breeds. Its development was studied by dissection and histological analysis in 45 puppies and its timing of radiological appearance was evaluated in 209 puppies. At least one sesamoid bone was present in all adult dogs, except for 14 dogs of six breeds of predominantly the small breed category. The lowest prevalence rate of 38.46% was exhibited in the French bulldog. The histological development could be divided into five stages. The first radiographic appearance corresponded to the coalescence of smaller ossification centers into one big nucleus (stage 4). The mean time of radiographic appearance was 108.4 days. This study provides extensive data on the prevalence and timing of the radiographic appearance of a sesamoid at the carpus of the dog. The data on radiographic appearance may be helpful in the age estimation of puppies.

Multicenter study to investigate factors associated with change in rectal temperature during anesthesia in dogs

OBJECTIVE

To determine factors associated with change in rectal temperature (RT) of dogs undergoing anesthesia.

ANIMALS

507 dogs.

PROCEDURES

In a prospective observational study, the RT of dogs undergoing anesthesia at 5 veterinary hospitals was recorded at the time of induction of anesthesia and at the time of recovery from anesthesia (ie, at the time of extubation). Demographic data, body condition score, American Society of Anesthesiologists (ASA) physical status classification, types of procedure performed and medications administered, duration of anesthesia, and use of heat support were also recorded. Multiple regression analysis was performed to determine factors that were significantly associated with a decrease or an increase (or no change) in RT. Odds ratios were calculated for factors significantly associated with a decrease in RT.

RESULTS

Among the 507 dogs undergoing anesthesia, RT decreased in 89% (median decrease, -1.2°C [-2.2°F]; range, -0.1°C to -5.7°C [-0.2°F to -10.3°F]), increased in 9% (median increase, 0.65°C [1.2°F]; range, 0.1°C to 2.1°C [3.8°F]), and did not change in 2%. Factors that significantly predicted and increased the odds of a decrease in RT included lower weight, ASA classification > 2, surgery for orthopedic or neurologic disease, MRI procedures, use of an α₂-adrenergic or μ-opioid receptor agonist, longer duration of anesthesia, and higher heat loss rate. Lack of μ-opioid receptor agonist use, shorter duration of anesthesia, and lower heat loss rate were significantly associated with an increase in RT.

CONCLUSIONS AND CLINICAL RELEVANCE

Multiple factors that were associated with a decrease in RT in dogs undergoing anesthesia were identified. Knowledge of these factors may help identify dogs at greater risk of developing inadvertent perianesthetic hypothermia.

The Physiological Conundrum That is the Domestic Dog

Across Mammalia, body size and lifespan are positively correlated. However, in domestic dogs, the opposite is true: small dogs have longer lives compared with large dogs. Here, I present literature-based data on life-history traits that may affect dog lifespan, including adaptations at the whole-organism, and organ-level. Then, I compare those same traits to wild canids. Because oxidative stress is a byproduct of aerobic metabolism, I also present data on oxidative stress in dogs that suggests that small breed dogs accumulate significantly more circulating lipid peroxidation damage compared with large breed dogs, in opposition to lifespan predictions. Further, wild canids have increased antioxidant concentrations compared with domestic dogs, which may aid in explaining why wild canids have longer lifespans than similar-sized domestic dogs. At the cellular level, I describe mechanisms that differ across size classes of dogs, including increases in aerobic metabolism with age, and increases in glycolytic metabolic rates in large breed dogs across their lifespan. To address potential interventions to extend lifespan in domestic dogs, I describe experimental alterations to cellular architecture to test the "membrane pacemaker" hypotheses of metabolism and aging. This hypothesis suggests that increased lipid unsaturation and polyunsaturated fatty acids in cell membranes can increase cellular metabolic rates and oxidative damage, leading to potential decreased longevity. I also discuss cellular metabolic changes of primary fibroblast cells isolated from domestic dogs as they are treated with commercially available drugs that are linked to lifespan and health span expansion.

Growth Curve and Energy Intake in Male and Female Cats

The aim of this study were (1) to characterize the growth curve in male and female cats, (2) to associate the growth and metabolizable energy intake (MEI) as an indirect measurement of the energy requirements, and (3) to determine the short-term effects of neutering on energy intake to maintain the bodyweight in young adult cats. Eighteen 5-months-old mixed breed cats were used in this study (males, n = 7 and BW = 2.2 ± 0.21 kg; females, n = 11 and BW = 2.0 ± 0.16 kg). The cats were fed to supply their metabolizable energy requirement for growth, adjusting the amounts to maintain an ideal body condition score. The animals were weighed every 15 days for 10 months (from 5 to 15 months old). At 12 months old, the cats were gonadectomized and the MEI was recorded for 3 months, up to 15 months old. Second-order, Gaussian, and spherical models were fitted to growth data. Male cats had higher energy intake for growth (MEI = 176.27^-0.037t, R² = 0.79) than females (MEI = 166.86^-0.044t, R² = 0.62), where t is the age in months. Male cats also reached mature weight later than female cats (16 and 13 months old, respectively). Neutering reduced the energy requirements of male (intact - 116.43 kcal/kg^0.67; gonadectomized - 98.65 kcal/kg^0.67; P < .01) and female cats (intact - 98.65 kcal/kg^0.67; gonadectomized - 76.16 kcal/kg^0.67; P < .01) on average 17.6%. This study suggests that in cats, males and females present different energy requirements since the early growth phases and, this difference remains after neutering in young adults. Female cats reach adult weight earlier than males.

Sex-differential non-specific effects of rabies vaccine in dogs: An extended analysis of a randomized controlled trial in a high-mortality population

Non-live rabies vaccines have been associated with both beneficial and detrimental effects on host population morbidity and mortality rates to unrelated infections in people and animals, and these non-specific effects may differ by sex. Previous animal studies may have been affected by bias, including selection bias due to loss to follow up in randomized controlled trials (RCTs). We previously reported results of an RCT in dogs on the effect of primary rabies vaccine administered at 6 weeks of age on all-cause mortality over a 7-week follow-up period, in a high-mortality population of owned dogs. Here, we report the results from the same trial of a second vaccination at 13 weeks of age, compared to a primary vaccination. Because a relatively high proportion of study subjects (30%) were lost to follow-up in the RCT, we also conducted an analysis to control for possible selection bias over both periods (6 to 13 weeks and 13 to 20 weeks of age). We found that primary rabies vaccination at 6 weeks of age substantially increased the hazard of death from all causes over the next 7 weeks among females (hazard ratio [HR] 2.69, 95% confidence intervals [CI] 1.27-5.69), but not among males (HR 0.91, 95% CI 0.32-2.59). Among survivors, administration of a second dose of rabies vaccine at 13 weeks of age was associated with a decreased hazard of death among males (HR 0.33, 95% CI 0.10-1.02) but not females (HR 1.64, 95% CI 0.59-4.58), when compared to the group receiving their first dose at this age. Based on our causal assumptions, we show that these results were not affected by selection bias. In this high-mortality dog population, receipt of a non-live rabies vaccine substantially affected all-cause mortality rates, with this effect being strongly modified by sex.

Dietary Supplementation with Housefly (Musca domestica) Maggot Meal in Growing Beagles: Hematology, Serum Biochemistry, Immune Responses and Oxidative Damage

The present study was carried out to evaluate the hematology, serum biochemistry, immune responses and oxidative damage of growing beagles fed a diet supplemented with housefly (Musca domestica) maggot meal (MM). Weanling beagles (initial body weight 2.69 ± 0.17 kg) were fed a control diet (0% MM) or experimental diet (5% MM) for 42 days. The results indicated that the diet supplemented with 5% MM had no significant effects on the hematology and serum biochemistry of growing beagles (P>0.05). Meanwhile, neither the serum concentrations of lysozyme and C-reactive protein nor the serum antibody responses to canine distemper virus and canine parvovirus were influenced by dietary MM supplementation (P>0.05). However, dogs in the experimental group had lower serum levels of malondialdehyde and protein carbonyl than those in the control group (P<0.05). These findings demonstrated that MM could be used as an alternative protein source in growing beagles without any adverse effects on hematology, serum biochemistry and immune responses. Furthermore, dietary MM could alleviate oxidative damage in growing beagles.

Energy Consumption of Young Military Working Dogs in Pre-Training in Germany

Simple Summary

Appropriate energy supply adjusted to the requirements of military working dogs at pre-training is a basic prerequisite for working dogs, so they are fully able to exercise. Therefore, twenty Belgian Shepherds var. Malinois were accompanied for four weeks during pre-training as military working dogs, and the amount of energy intake was evaluated. Changes in body constitution were assessed by measuring body weight and shoulder height, as well as thickness of subcutaneous fat tissue, and of Musculus sacrocaudalis dorsalis lateralis (MSCDL). Energy intake amounted to, on average, 244 kcal/kg body weight (BW)^0.75 daily. Changes to body constitution (increases in body weight, shoulder height, and thickness of the MSCDL, as well as a reduction of the thickness of the subcutaneous fat tissue lying on the MSCDL) might be attributed to training-induced muscle growth and physiological growth in size. In addition to training intensity, influences of ambient temperature and physiological body growth seemed to be important contributing factors in the supply of energy for military working dogs (MWDs) during pre-training.

Abstract

Many factors have specific effects, in varying degrees of intensity, on the metabolic energy requirements of working dogs. Appropriate energy supply adjusted to the requirements of military working dogs at pre-training is a basic prerequisite for working dogs, so they are fully able to exercise. Therefore, more knowledge obtained under standardized conditions would be advantageous. Twenty intact Belgian Shepherds var. Malinois at the age of 12 months were accompanied for four weeks during pre-training (odour detection, obedience training, and protection work) as military working dogs (MWDs) in Germany (ambient temperature about 7.8 °C), and the amount of energy intake was evaluated. To assess changes in body constitution, body weight and shoulder height were measured, and the thickness of subcutaneous fat tissue (SCF), and of Musculus sacrocaudalis dorsalis lateralis (MSCDL), were recorded via ultrasound. Energy intake amounted to, on average, 244 ± 34 kcal/kg body weight (BW)^0.75 daily. Increases in body weight, shoulder height, and thickness of the MSCDL, as well as a reduction of SCF thickness lying on the MSCDL, were observed. Changes of body constitution might be attributed to training-induced muscle growth and physiological growth in size. In addition to training intensity, influences of ambient temperature and physiological body growth seemed to be important contributing factors in the supply of energy for MWDs during pre-training.

Untangling life span and body mass discrepancies in canids: phylogenetic comparison of oxidative stress in blood from domestic dogs and wild canids

Canids are a morphological and physiological diverse group of animals, with the most diversity found within one species, the domestic dog. Underlying observed morphological differences, there must also be differences at other levels of organization that could lead to elucidating aging rates and life span disparities between wild and domestic canids. Furthermore, small-breed dogs live significantly longer lives than large-breed dogs, while having higher mass-specific metabolic rates and faster growth rates. At the cellular level, a clear mechanism underlying whole animal traits has not been fully elucidated, although oxidative stress has been implicated as a potential culprit of the disparate life spans of domestic dogs. We used plasma and red blood cells from known aged domestic dogs and wild canids, and measured several oxidative stress variables: total antioxidant capacity (TAC), lipid damage, and enzymatic activities of catalase, superoxide dismutase, and glutathione peroxidase (GPx). We used phylogenetically informed general linear mixed models and nonphylogenetically corrected linear regression analysis. We found that lipid damage increases with age in domestic dogs, whereas TAC increases with age and TAC and GPx activity increases as a function of age/maximum life span in wild canids, which may partly explain longer potential life spans in wolves. As body mass increases, TAC and GPx activity increase in wild canids, but not domestic dogs, highlighting that artificial selection may have decreased antioxidant capacity in domestic dogs. We found that small-breed dogs have significantly higher circulating lipid damage compared with large-breed dogs, concomitant to their high mass-specific metabolism and higher growth rates, but in opposition to their long life spans.

A Preliminary Study of the Effect of Hyperadrenocorticism on Calcium and Phosphate Concentrations, Parathyroid Hormone and Markers of Bone Turnover in Dogs

Reports on the effects of hyperadrenocorticism (HAC) on bone turnover in dogs are largely confined to radiographic studies. The aim of this study was to more accurately assess bone turnover in dogs with HAC by measuring circulating total and ionized calcium and phosphate concentrations, both intact and whole parathyroid hormone (PTH) concentrations and markers of both osteoblastic (osteocalcin) and osteoclastic [carboxyterminal cross-linked telopeptide of type 1 collagen (ICTP) and urine aminoterminal telopeptide of type 1 collagen (NTX) activity]. Dogs with HAC and a control group were prospectively enrolled for comparison. Results from 49 dogs with HAC were compared with 39 dogs from a hospital control population. Plasma intact and whole PTH concentrations were determined using a human immunoradiometric assay. Serum osteocalcin and NTX concentrations were measured using human enzyme linked immunosorbent assays. Serum ICTP concentration was measured using a human radioimmunoassay. Total calcium concentrations in dogs with HAC (2.67 ± 0.25 mmol/L) were not significantly different than in the control group (2.67 ± 0.14 mmol/L). By contrast, phosphate concentrations were significantly (P = 0.0143) higher in dogs with HAC (1.46 ± 0.30 mmol/L) compared to the control group (1.28 ± 0.33 mmol/L). The median intact PTH concentration in HAC dogs was 9.25 (range, 1.34–95.45) pmol/L, which was significantly (P < 0.0001) higher than in the control group [median, 3.88 (range, 2.01–10.31) pmol/L]. Whole PTH concentrations were also significantly (P < 0.0001) higher in the HAC group [median, 4.61 (range, 0.56–125.16) pmol/L] compared to the control group [median, 1.83 (range, 0.88–6.81) pmol/L]. Serum osteocalcin and urine NTX concentrations were not significantly different between the two groups of dogs. The median ICTP concentration in dogs with HAC was 2.98 (range, 1.15–6.62) ng/mL which was significantly (P < 0.0001) lower than in the control dogs [median, 7.30 (range, 3.68–21.25) ng/mL]. Both whole and intact PTH concentrations are increased in dogs with HAC compared to a hospital control population. This does not however appear to be associated with a decrease in bone formation (as assessed by osteocalcin) or an increase in bone resorption (as assessed by ICTP and urine NTX).

Chemical structures of oligosaccharides in milks of the American black bear (Ursus americanus americanus) and cheetah (Acinonyx jubatus)

The milk oligosaccharides were studied for two species of the Carnivora: the American black bear (Ursus americanus, family Ursidae, Caniformia), and the cheetah, (Acinonyx jubatus, family Felidae, Feliformia). Lactose was the most dominant saccharide in cheetah milk, while this was a minor saccharide and milk oligosaccharides predominated over lactose in American black bear milk. The structures of 8 neutral saccharides from American black bear milk were found to be Gal(β1-4)Glc (lactose), Fuc(α1-2)Gal(β1-4)Glc (2'-fucosyllactose), Gal(α1-3)Gal(β1-4)Glc (isoglobotriose), Gal(α1-3)[Fuc(α1-2)]Gal(β1-4)Glc (B-tetrasaccharide), Gal(α1-3)[Fuc(α1-2)]Gal(β1-4)[Fuc(α1-3)]Glc (B-pentasaccharide), Fuc(α1-2)Gal(β1-4)[Fuc(α1-3)]GlcNAc(β1-3)Gal(β1-4)Glc (difucosyl lacto-N-neotetraose), Gal(α1-3)Gal(β1-4)[Fuc(α1-3)]GlcNAc(β1-3)Gal(β1-4)Glc (monogalactosyl monofucosyl lacto-N-neotetraose) and Gal(α1-3)Gal(β1-4)GlcNAc(β1-3)Gal(β1-4)Glc (Galili pentasaccharide). Structures of 5 acidic saccharides were also identified in black bear milk: Neu5Ac(α2-3)Gal(β1-4)Glc (3'-sialyllactose), Neu5Ac(α2-6)Gal(β1-4)GlcNAc(β1-3)[Fuc(α1-2)Gal(β1-4)GlcNAc(β1-6)]Gal(β1-4)Glc (monosialyl monofucosyl lacto-N-neohexaose), Neu5Ac(α2-6)Gal(β1-4)GlcNAc(β1-3)[Gal(α1-3)Gal(β1-4)GlcNAc(β1-6)]Gal(β1-4)Glc (monosialyl monogalactosyl lacto-N-neohexaose), Neu5Ac(α2-6)Gal(β1-4)GlcNAc(β1-3){Gal(α1-3)Gal(β1-4)[Fuc(α1-3)]GlcNAc(β1-6)}Gal(β1-4)Glc (monosialyl monogalactosyl monofucosyl lacto-N-neohexaose), and Neu5Ac(α2-6)Gal(β1-4)GlcNAc(β1-3){Gal(α1-3)[Fuc(α1-2)]Gal(β1-4)[Fuc(α1-3)]GlcNAc(β1-6)}Gal(β1-4)Glc (monosialyl monogalactosyl difucosyl lacto-N-neohexaose). A notable feature of some of these milk oligosaccharides is the presence of B-antigen (Gal(α1-3)[Fuc(α1-2)]Gal), α-Gal epitope (Gal(α1-3)Gal(β1-4)Glc(NAc)) and Lewis x (Gal(β1-4)[Fuc(α1-3)]GlcNAc) structures within oligosaccharides. By comparison to American black bear milk, cheetah milk had a much smaller array of oligosaccharides. Two cheetah milks contained Gal(α1-3)Gal(β1-4)Glc (isoglobotriose), while another cheetah milk did not, but contained Gal(β1-6)Gal(β1-4)Glc (6'-galactosyllactose) and Gal(β1-3)Gal(β1-4)Glc (3'-galactosyllactose). Two cheetah milks contained Gal(β1-4)GlcNAc(β1-3)[Gal(β1-4)GlcNAc(β1-6)]Gal(β1-4)Glc (lacto-N-neohexaose), and one cheetah milk contained Gal(β1-4)Glc-3'-O-sulfate. Neu5Ac(α2-8)Neu5Ac(α2-3)Gal(β1-4)Glc (disialyllactose) was the only sialyl oligosaccharide identified in cheetah milk. The heterogeneity of milk oligosaccharides was found between both species with respect of the presence/absence of B-antigen and Lewis x. The variety of milk oligosaccharides was much greater in the American black bear than in the cheetah. The ratio of milk oligosaccharides-to-lactose was lower in cheetah (1:1-1:2) than American black bear (21:1) which is likely a reflection of the requirement for a dietary supply of N-acetyl neuraminic acid (sialic acid), in altricial ursids compared to more precocial felids, given the role of these oligosaccharides in the synthesis of brain gangliosides and the polysialic chains on neural cell adhesion.

Nutrition consultation for an overweight growing Bernese Mountain Dog-A case report

In growing dogs, overweight is assimilated and attributed to a fast growth rate. Proper nutrition plays a very important role during growth as mistakes in feeding may lead to severe disease. This case report is an example for excessive weight gain during growth that, particularly in large breed dogs, may lead to skeletal disorders such as improper alignments of the limbs. If body weight gain exceeds the ideal range of the individual growth curve (by initially 4 kg in this case), fast growth may lead to growth disturbances and associated chronic diseases. These cases require a dietary adaption. However, the success in the nutritional management of the body weight relies largely on the owner's compliance.

Effects of Alfaxalone or Propofol on Giant-Breed Dog Neonates Viability During Elective Caesarean Sections

Attention must be paid to C-section anesthesia effects on mother and offspring. Alfaxalone induction results in improved puppy viability when compared to propofol. The present study aims to evaluate effects of alfaxalone or propofol induction for elective C-section on newborns, expressed as Apgar score and fetal fluids cortisol concentration. Anesthesia was induced with alfaxalone 3 mg/kg iv in 5 bitches (group A), and propofol 4 mg/kg iv in another 5 (group P), maintained with isoflurane. Amniotic and allantoic fluids were collected to determine cortisol concentration. Apgar score, litter size, newborn gender, birth-weight, maternal age, and parity were recorded. ANOVA, U Mann-Whitney test and ANCOVA assessed the effects of drugs on the Apgar score and fetal fluids cortisol. Thirty-six puppies were randomly selected for the study: 16 from group A and 20 from group P. Only the Apgar score significantly differed between groups. ANCOVA confirmed a significantly higher Apgar score in group A underlining the influence of fetal fluids cortisol concentrations, both resulting in covariates. Present results confirm the effect of anesthesia on the Apgar score of newborns, which is significantly higher for alfaxalone than propofol, suggesting the use of fetal fluids cortisol as a covariate. These findings could be a starting point for further investigations when less viable puppies are detected or expected, such as during an emergency C-section.

Birth weight as a risk factor for neonatal mortality: Breed-specific approach to identify at-risk puppies

In numerous species, low birth weight is a risk factor for neonatal mortality. In the canine species, definition of a low birth weight is complex due to the huge interbreed variability in size. To identify puppies at higher risk of neonatal death, data from 6,694 puppies were analysed. The data were collected from 75 French breeding kennels, examining 27 breeds and totaling 1,202 litters of puppies. Generalised linear mixed models allowed to identify birth weight, birth weight heterogeneity within the litter, and size of the breeding kennel as significant risk factors for neonatal mortality. Receiver Operating Characteristics (ROC) and classification and regression tree (CART) analyses were combined to define breed specific thresholds for birth weight allowing the identification of puppies at higher risk of neonatal mortality. Due to differences in birth weights between breeds, including when belonging to the same breed size, analyses were conducted at the breed level. First, ROC analysis thresholds were successfully established for 12 breeds (area under the ROC ≥ 0.70; sensitivity ≥ 75%; specificity: 45-68%) and they ranged from 162 g in the Maltese to 480 g in the Bernese Mountain dog. Secondly, CART analysis thresholds from 22 breeds ranged from 105 g in the Maltese and 436 g in the Boxer. Puppies were grouped into three categories according to birth weight: low, moderate and high risk of neonatal mortality (higher than the ROC threshold, between ROC and CART thresholds, and lower than the CART threshold respectively). In the current study, 44% of the puppies were classified as at moderate risk and 5.3% for a high risk of neonatal mortality. Thresholds defined by CART analysis (and not ROC analysis) were used to define low birth weight puppies and were sometimes quite different between breeds with similar birth weight distributions suggesting a variable relationship between birth weight reduction and neonatal death. These results allow the identification of puppies at an increased risk of neonatal death, thus requiring specific nursing to improve their chances of survival. With these high risk puppies identified, both animal welfare and kennel productivity is predicted to improve.

Variation in the position of the conus medullaris and dural sac in adult dogs

Although it has long been stated that the level of spinal cord termination varies depending on the size of the dog, the evidence for this remains limited. The aim of this study is to investigate the position of the conus medullaris (CM) and dural sac (DS) in a population of dogs of varying size. MRIs of the thoracolumbosacral spine of 101 dogs were included. The location of CM and DS was determined on sagittal T2-weighted images and T1-weighted images, respectively, by three independent observers. The bodyweight and the back length were used as markers of size. Regression analysis showed that the termination point of the CM had a statistically significant relationship with bodyweight (R²=0.23, P<0.05). Although not statistically significant (P=0.058), a similar relationship was found between CM and back length (R²=0.21). No statistically significant relationship was found between the termination point of the DS and bodyweight (P=0.24) or back length (P=0.19). The study confirms the terminal position of the CM is dependent on size, with a more cranial position with increasing size; however, the termination point of DS remains constant irrespective of dog size.

Glutathione S-transferase theta genotypes and environmental exposures in the risk of canine transitional cell carcinoma

Introduction

Transitional cell carcinoma (TCC) in humans is associated with environmental exposures and variants in glutathione S‐transferase (GST) genes. Scottish Terriers have a high breed risk for TCC, but the relationship between genetic and environmental risk in dogs is not fully understood.

Hypotheses

Scottish Terriers have a higher frequency of GST‐theta variants compared to lower risk breeds. Dogs with TCC of any breed have a higher frequency of GST‐theta variants along with higher environmental exposures, compared to controls.

Animals

One hundred and five Scottish Terriers and 68 controls from lower risk breeds; 69 dogs of various breeds with TCC, and 72 breed‐ and sex‐matched unaffected geriatric dogs.

Methods

In this prospective case‐control study, dogs were genotyped for 3 canine GST‐theta variants: GSTT1 I2+28 G>A, a GSTT1 3′UTR haplotype, and GSTT5 Asp129_Gln130del. Owners of dogs with TCC and unaffected geriatric controls completed a household environmental questionnaire.

Results

The GSTT1 3′UTR haplotype and GSTT5 Asp129_Gln130del variants were significantly underrepresented in Scottish Terriers (minor allele frequency [MAF] = 0.000 for both), compared to dogs from lower risk breeds (MAF = 0.108 and 0.100; P ≤ .0002). Dogs with TCC did not differ from unaffected geriatric controls across the 3 investigated loci. Transitional cell carcinoma was associated with household insecticide use (odds ratio [OR] = 4.28, 95% confidence interval [CI] = 1.44‐12.33, P = .02), and was negatively associated with proximity to a farm (OR = 0.49, 95% CI = 0.25‐0.99, P = .04).

Conclusions and Clinical Importance

Low‐activity GST‐theta loci are unlikely contributors to TCC risk in dogs. Increased risk is associated with household insecticide use, and possibly with less rural households.

Battle of the Sexes in Best of Breed: Sex Influences Dogs' Success in the Show Ring

Simple Summary

When breeding dogs, the dam and the sire contribute equally to the genetics of each of their puppies, and so each parent should be equally important to show-ring success. The current study collated samples of dog show results to explore relationships between sex and the likelihood of success in the show ring. It focused on toy and giant breeds to explore any differences in equity, if it existed, at either end of the size spectrum. It revealed that the rate at which male and female dogs were exhibited were similar but that male dogs were a significant advantage of winning Best of Breed titles.

Abstract

Much of the research on pedigree dog breeding has been directed towards understanding the implications of reduced genetic diversity and the prevalence of inherited disorders. An example is the potential role of the popular sire effect in perpetuating genetic defects. If male dogs are more likely than bitches to be identified as examples of members of a breed that align with breed standard, they may be selected for breeding earlier. This may contribute to the influence of individual males and contribute to popular sire effect. Conversely, if breed standards are written in a sex-neutral fashion, and if dogs are entered, exhibited, and judged in a sex-neutral fashion, then we would expect the success of female dogs in the show ring to be equal to that of their male counterparts. With a focus on toy and giant breeds, the current pilot study collated samples of dog show results to explore relationships between sex and the likelihood of success in the show ring. It focused on toy and giant breeds to explore any differences in equity, if it existed, at either end of the size and concomitant age-at-maturation spectrum. For the purpose of this study, toy breeds were those that weigh < 10 kg at maturity while giant breed dogs were those that exceed 45 kg. Within these two clusters, the least (n = 3) and most popular (n = 3) breeds were then selected to explore any potential role of sex on success in the show ring. The popularity of breeds was determined using the numbers of dogs registered with the Australian National Kennel Council. Using results from dog shows (n = 18) from 2015 to 2016, data on 1,080 dogs were obtained. Within these 12 breeds for the 18 shows, there were 137 Best of Breed (BOB) titles awarded: Pug (n = 18), Toy Poodle (n = 18), Bullmastiff (n = 14), Rottweiler (n = 17), Fox Terrier (Smooth) (n = 18), Bloodhound (n = 3), Schnauzer (miniature) (n = 15), Great Dane (n = 17), Norfolk Terrier (n = 10), Norwich Terrier (n = 5), Central Asian Shepherd Dog (n = 2). Despite the near parity of male and female dogs being exhibited, of these 137 titles, 86 (62.8%) were awarded to male dogs (at least 41 individuals) and 51 (37.2%) to female dogs (at least 32 individuals) showing that male dogs are more likely to win BOB titles (χ² = 9.4455, df = 1, p-value = 0.002117). Among the toy subset of breeds, this effect was higher (χ² = 6.798, df = 1, p-value = 0.009126) than among the giant breed subset, for whom the advantage to male dogs did not reach statistical significance versus χ² = 3.0967, df = 1, p-value = 0.07845). This suggests that judges find the male dogs more appealing, presumably because they are more aligned with breed standards.

Musculotendon excursion potential, tendon slack and muscle fibre length: the interaction of the canine gastrocnemius muscle and tendon

Although the form-function relation of muscles and tendons has been studied extensively, little in vivo data exist on the musculotendon properties of the gastrocnemius complex in dogs. Using a combination of ultrasound and 3D motion tracking, musculotendon parameters were obtained in vivo from the lateral gastrocnemius muscle and the gastrocnemius tendon in nine healthy Labrador Retrievers. These parameters include musculotendon length and excursion potential, tendon slack length, muscle belly length, muscle fibre length, pennation angle and architectural index. This study also examined the variation of muscle and tendon length contributions to musculotendon length, as well as the relation between musculotendon excursion potential and muscle fibre length or tendon length. To facilitate comparison between dog breeds, the femur length as a potential scaling parameter was examined. In the Labrador gastrocnemius musculotendon complex, the tendon contributes 41% (± 9%) of musculotendon length. In longer musculotendon complexes, the contribution of the muscle belly increases while the tendon contribution decreases. Longer muscle belly and musculotendon complexes were, however, associated with shorter muscle fibres. No significant relations were found between musculotendon excursion potential and muscle fibre length or tendon slack length, and femur length did not prove to be a reliable scale factor for the length-related musculotendon parameters examined in this study. Longer musculotendon complexes exhibit relatively longer muscle bellies, which are in turn associated with shorter muscle fibre lengths. This trade-off between gastrocnemius muscle belly length and muscle fibre length might have the advantage that muscle volume stays constant regardless of the length of the limbs.

Effect of neuroactive nutritional supplementation on body weight and composition in growing puppies

Nutritional factors can dramatically affect development of young animals during the early stage of life. The objective of the present study was to examine the effects of a neuroactive nutritional supplement (NNS) containing DHA, taurine, carotenoids and vitamins on the body weight and body composition of growing puppies. A total of twenty-four 2-month-old Beagles were fed a nutritionally complete and balanced base diet and a control supplement daily during an initial 1-month baseline assessment, after which they were divided into control and treatment groups. They were fed daily either control or treatment supplements in addition to the base diet from 3 to 12 months of age. Lean body mass and fat mass were assessed using quantitative magnetic resonance scans at 0 (baseline), 3, 6 and 9 months of treatment. Total body weight and lean body mass did not differ between groups over time. The puppies in the treatment group showed a trend of reduced fat gain compared with those in the control group, and with a marginally significant difference at 6 months (P = 0·05). At 3 months, insulin-like growth factor 1 was higher (P = 0·02) in the treatment group compared with the control group. At 9 months, fasting lipid levels were lower (P < 0·05) and fat-oxidation metabolite 3-hydroxybutyrate was higher (P < 0·05) in the treatment group compared with the control group. These results may indicate that NNS has an impact on puppy growth and development, possibly by promoting fat metabolism; further investigation would be necessary to determine the full impact of this supplement on growth and development.

Parvovirus Infection Is Associated With Myocarditis and Myocardial Fibrosis in Young Dogs

Perinatal parvoviral infection causes necrotizing myocarditis in puppies, which results in acute high mortality or progressive cardiac injury. While widespread vaccination has dramatically curtailed the epidemic of canine parvoviral myocarditis, we hypothesized that canine parvovirus 2 (CPV-2) myocardial infection is an underrecognized cause of myocarditis, cardiac damage, and/or repair by fibrosis in young dogs. In this retrospective study, DNA was extracted from formalin-fixed, paraffin-embedded tissues from 40 cases and 41 control dogs under 2 years of age from 2007 to 2015. Cases had a diagnosis of myocardial necrosis, inflammation, or fibrosis, while age-matched controls lacked myocardial lesions. Conventional polymerase chain reaction (PCR) and sequencing targeting the VP1 to VP2 region detected CPV-2 in 12 of 40 cases (30%; 95% confidence interval [CI], 18%-45%) and 2 of 41 controls (5%; 95% CI, 0.1%-16%). Detection of CPV-2 DNA in the myocardium was significantly associated with myocardial lesions ( P = .003). Reverse transcription quantitative PCR amplifying VP2 identified viral messenger RNA in 12 of 12 PCR-positive cases and 2 of 2 controls. PCR results were confirmed by in situ hybridization, which identified parvoviral DNA in cardiomyocytes and occasionally macrophages of juvenile and young adult dogs (median age 61 days). Myocardial CPV-2 was identified in juveniles with minimal myocarditis and CPV-2 enteritis, which may indicate a longer window of cardiac susceptibility to myocarditis than previously reported. CPV-2 was also detected in dogs with severe myocardial fibrosis with in situ hybridization signal localized to cardiomyocytes, suggesting prior myocardial damage by CPV-2. Despite the frequency of vaccination, these findings suggest that CPV-2 remains an important cause of myocardial damage in dogs.

Growth standard charts for monitoring bodyweight in dogs of different sizes

Limited information is available on what constitutes optimal growth in dogs. The primary aim of this study was to develop evidence-based growth standards for dogs, using retrospective analysis of bodyweight and age data from >6 million young dogs attending a large corporate network of primary care veterinary hospitals across the USA. Electronic medical records were used to generate bodyweight data from immature client-owned dogs, that were healthy and had remained in ideal body condition throughout the first 3 years of life. Growth centile curves were constructed using Generalised Additive Models for Location, Shape and Scale. Curves were displayed graphically as centile charts covering the age range 12 weeks to 2 years. Over 100 growth charts were modelled, specific to different combinations of breed, sex and neuter status. Neutering before 37 weeks was associated with a slight upward shift in growth trajectory, whilst neutering after 37 weeks was associated with a slight downward shift in growth trajectory. However, these shifts were small in comparison to inter-individual variability amongst dogs, suggesting that separate curves for neutered dogs were not needed. Five bodyweight categories were created to cover breeds up to 40kg, using both visual assessment and hierarchical cluster analysis of breed-specific growth curves. For 20/24 of the individual breed centile curves, agreement with curves for the corresponding bodyweight categories was good. For the remaining 4 breed curves, occasional deviation across centile lines was observed, but overall agreement was acceptable. This suggested that growth could be described using size categories rather than requiring curves for specific breeds. In the current study, a series of evidence-based growth standards have been developed to facilitate charting of bodyweight in healthy dogs. Additional studies are required to validate these standards and create a clinical tool for growth monitoring in pet dogs.

Small-sized newborn dogs skeletal development: radiologic, morphometric, and histological findings obtained from spontaneously dead animals

BACKGROUND

Very little is known about neonatal skeletal development in small-sized purebred dogs. In order to improve this knowledge, 27 spontaneously dead puppies belonging to small-sized breeds were enrolled in this study for radiologic, histological and morphometric investigations.

RESULTS

The appearance of the limb secondary ossification centers and the onset of their formation were clearly observed by x rays and confirmed by histological evidences. Radiographic and anatomic measurements of limb bones length and skull length and width were positively correlated with body weight and age of the subjects and the body weight was positively correlated with radius bone mineral density, as demonstrated by dual-energy x-rays absorptiometry.

CONCLUSIONS

These data provided original information on the growth of newborn small-sized breed dogs, and suggest that cadavers may be useful to study skeletal development.

A National Census of Birth Weight in Purebred Dogs in Italy

Simple Summary

Birth weight is a key factor for neonatal mortality and morbidity in most mammalian species. The great morphological variability in size, body weight and breed, as well as in skeletal and cranial conformation makes it challenging to define birth weight standards in dogs. A total of 3293 purebred pups were surveyed to study which maternal aspects can determine birth weight considering head and body shape, size, body weight and breed in bitches, as well as litter size and sex in pups. In our sample, multivariate analysis outcomes suggested that birth weight and litter size were directly proportional to maternal size. The maternal body shape influenced both birth weight and litter size, whereas the maternal head shape had impact only on birth weight. Sex differences in birth weight were found. Birth weight and litter size also varied among breeds. The results of the present study could have practical implications allowing one to identify pups in need of admission to intensive nursing care, as occurs in humans. A deeper knowledge of the factors that significantly influence birth weight could positively affect the canine breeding management helping to prevent and reduce neonatal mortality.

Abstract

Despite increasing professionalism in dog breeding, the physiological range of birth weight in this species remains unclear. Low birth weight can predispose to neonatal mortality and growth deficiencies in humans. To date, the influence of the morphotype on birth weight has never been studied in dogs. For this purpose, an Italian census of birth weight was collected from 3293 purebred pups based on maternal morphotype, size, body weight and breed, as well as on litter size and sex of pups. Multivariate analysis outcomes showed that birth weight (p < 0.001) and litter size (p < 0.05) increased with maternal size and body weight. Birth weight was also influenced by the maternal head and body shape, with brachycephalic and brachymorph dogs showing the heaviest and the lightest pups, respectively (p < 0.001). Birth weight decreased with litter size (p < 0.001), and male pups were heavier than females (p < 0.001). These results suggest that canine morphotype, not only maternal size and body weight, can affect birth weight and litter size with possible practical implications in neonatal assistance.