Longitudinal evidence for the emergence of multiple intelligences in assistance dog puppies.

Cognitive test batteries suggest that adult dogs have different types of cognitive abilities that vary independently. In the current study, we tested puppies repeatedly over a crucial period of development to explore the timing and rate at which these different cognitive skills develop. Service dog puppies (n = 113), raised using two different socialization strategies, were either tested longitudinally (n =91) or at a single time point (n = 22). Subjects tested longitudinally participated in the battery every two weeks during and just beyond their final period of rapid brain growth (from approximately 8-20 weeks of age). Control puppies only participated in the test battery once, which allowed us to evaluate the impact of repeated testing. In support of the multiple intelligences hypothesis (MIH), cognitive skills emerged at different points across the testing period, not simultaneously. Maturational patterns also varied between cognitive skills, with puppies showing adult-like performance on some tasks only weeks after a skill emerged, while never achieving adult performance in others. Differences in rearing strategy did not lead to differences in developmental patterns while, in some cases, repeated testing did. Overall, our findings provide strong support for the MIH by demonstrating differentiated development across the cognitive abilities tested.

Establishing a clinically applicable frailty phenotype screening tool for aging dogs.

Introduction: Frailty is a well-defined clinical syndrome in humans caused by accumulation of impairments which result in loss of reserve capacity and increased vulnerability to disability, dependence, and death. Dogs are of particular interest in studies of frailty due to the similarities they share with people in their environment, lifestyles, and age-related diseases. Materials and methods: The aim of this study was to develop a frailty phenotype screening tool, based on previously validated measures in dogs, which could be easily applied in the clinical setting, and which was predictive of all-cause, short term (6-month) mortality. The study was conducted in two phases. In phase 1, a retrospective cohort of 51 dogs was used to identify and evaluate potential measures for the five domains of frailty. This information was then used to develop a simple frailty phenotype based on examination findings and owner directed questions. In phase 2 of the study, this phenotype was evaluated in a prospective cohort of 198 dogs aged 9 years or older from multiple different specialty and primary care services to determine how the phenotype performed across a diverse canine population. Results: The developed frailty phenotype was predictive of all-cause, short-term mortality independent of age, sex, or weight (hazard ratio = 4.71; 95% CI, 2.66-8.8). Of the covariates evaluated only breed was significant, with purebred dogs having 1.85 times higher mortality than mixed breed dogs (95% CI, 1.04-3.31). The frailty phenotype performed similarly across all hospital services from which patients were enrolled. Conclusion: Based on these findings, the defined frailty phenotype represents a valuable screening tool for early risk identification and intervention, and can aid in clinical decision making for owners and veterinarians. Additionally, it will promote further research into the understanding and treatment of frailty in dogs.

Cross-sectional and longitudinal analysis of health-related quality of life (HRQoL) in senior and geriatric dogs.

Advancements in veterinary medicine have resulted in increased life spans for dogs, necessitating a better understanding of quality of life for older dogs. This study aimed to evaluate quality of life (QoL) progression and its potential association with mortality in senior and geriatric dogs. The Canine Owner-Reported Quality of Life Questionnaire (CORQ), consisting of 17 questions across four domains (vitality, companionship, pain, and mobility) was employed. Higher scores indicated better quality of life, with 7 as the highest potential score for each question. In a cross-sectional analysis including 92 dogs, we found an inverse correlation between overall CORQ (and all domain scores) and fractional lifespan. The domain of vitality demonstrated the lowest scores, while companionship exhibited the highest. A longitudinal analysis, including 34 dogs, revealed that when dogs reach the geriatric stage (100% of their calculated lifespan), their expected overall CORQ is 5.95 out of 7, and dogs are expected to have a monthly decline of 0.05 units in the score. Cox proportional hazard analysis demonstrated a significant association between overall CORQ scores and mortality, with dogs scoring below 5.35 being at a higher risk of mortality. This study underscores the association between aging, declining quality of life, and increased mortality risk in aging dogs.

Voxelwise analysis of the central hearing pathway in senior dogs reveals changes associated with fractional lifespan.

Presbycusis, or age-related hearing loss, affects both elderly humans and dogs, significantly impairing their social interactions and cognition. In humans, presbycusis involves changes in peripheral and central auditory systems, with central changes potentially occurring independently. While peripheral presbycusis in dogs is well-documented, research on central changes remains limited. Diffusion tensor imaging (DTI) is a useful tool for detecting and quantifying cerebral white matter abnormalities. This study used DTI to explore the central auditory pathway of senior dogs, aiming to enhance our understanding of canine presbycusis. Dogs beyond 75% of their expected lifespan were recruited and screened with brainstem auditory evoked response testing to select dogs without severe peripheral hearing loss. Sixteen dogs meeting the criteria were scanned using a 3 T magnetic resonance scanner. Tract-based spatial statistics was used to analyze the central auditory pathways. A significant negative correlation between fractional lifespan and fractional anisotropy was found in the acoustic radiation, suggesting age-related white matter changes in the central auditory system. These changes, observed in dogs without severe peripheral hearing loss, may contribute to central presbycusis development.

A randomized, controlled clinical trial demonstrates improved owner-assessed cognitive function in senior dogs receiving a senolytic and NAD+ precursor combination.

Age-related decline in mobility and cognition are associated with cellular senescence and NAD + depletion in dogs and people. A combination of a novel NAD + precursor and senolytic, LY-D6/2, was examined in this randomized controlled trial. Seventy dogs with mild to moderate cognitive impairment were enrolled and allocated into placebo, low or full dose groups. Primary outcomes were change in cognitive impairment measured with the owner-reported Canine Cognitive Dysfunction Rating (CCDR) scale and change in activity measured with physical activity monitors. Fifty-nine dogs completed evaluations at the 3-month primary endpoint, and 51 reached the 6-month secondary endpoint. There was a significant difference in CCDR score across treatment groups from baseline to the primary endpoint (p = 0.02) with the largest decrease in the full dose group. No difference was detected between groups using in house cognitive testing. There were no significant differences between groups in changes in measured activity. The proportion of dogs that improved in frailty and owner-reported activity levels and happiness was higher in the full dose group than other groups, however this difference was not significant. Adverse events occurred equally across groups. All groups showed improvement in cognition, frailty, and activity suggesting placebo effect and benefits of trial participation. We conclude that LY-D6/2 improves owner-assessed cognitive function over a 3-month period and may have broader, but more subtle effects on frailty, activity and happiness as reported by owners.

2024 ISFM and AAFP consensus guidelines on the long-term use of NSAIDs in cats.

PRACTICAL RELEVANCE: Non-steroidal anti-inflammatory drugs (NSAIDs) are widely used and are effective for the management of pain in cats. These Guidelines will support veterinarians in decision-making around prescribing NSAIDs in situations of chronic pain, to minimise adverse effects and optimise pain management. Information is provided on mechanism of action, indications for use, screening prior to prescription, use in the presence of comorbidities, monitoring of efficacy, and avoidance and management of adverse effects. CLINICAL CHALLENGES: The cat's unique metabolism should be considered when prescribing any medications, including NSAIDs. Chronic pain may be challenging to detect in this species and comorbidities, particularly chronic kidney disease, are common in senior cats. Management of chronic pain may be complicated by prescription of other drugs with the potential for interactions with NSAIDs. EVIDENCE BASE: These Guidelines have been created by a panel of experts brought together by the International Society of Feline Medicine (ISFM) and American Association of Feline Practitioners (AAFP). Information is based on the available literature, expert opinion and the panel members' experience.

Pilot Study on the Efficacy and Safety of Long-Term Oral Imepitoin Treatment for Control of (Thunder)Storm-Associated Noise Phobia/Noise Aversion in Dogs Using an Individualized-Dose Titration Approach.

Imepitoin is a low-affinity partial agonist for benzodiazepine binding sites of gamma-aminobutyric acid receptors with anxiolytic effects. It has been shown to reduce anxiety during noise-related events in dogs when given at 30 mg/kg PO BID, although this dose was associated with ataxia and increased appetite in some cases. The objective of this study was to assess its safety and efficacy for storm anxiety when started at 10 mg/kg PO BID and titrated to effect up to 30 mg/kg PO BID during storm season. Significant decreases in anxiety scores were seen in weekly surveys and storm logs (SLs) at 10, 20 and 30 mg/kg PO BID. Serious adverse events (AEs) were not reported in any subject. Ataxia was the most commonly reported non-serious AE (14/33), followed by increased hunger (13/33). The frequency of AEs was higher in the 20 mg/kg PO BID group than in the 10 mg/kg group PO BID. No clinically significant changes were seen in lab work pre- and post-study. In conclusion, Imepitoin given during storm season at doses ranging from 10 to 30 mg/kg PO BID reduced clinical signs of fear and anxiety during storms for the dogs in this study. These findings support the use of an individually titrated dose.

Longitudinal Analysis of Canine Oral Microbiome Using Whole Genome Sequencing in Aging Companion Dogs.

Aged companion dogs have a high prevalence of periodontal disease and canine cognitive dysfunction syndrome (CCDS) and the two disorders are correlated. Similarly, periodontal disease and Alzheimer's Disease are correlated in people. However, little is known about the oral microbiota of aging dogs. The goal of this project was to characterize the longitudinal changes in oral microbiota in aged dogs. Oral swabs were taken from ten senior client-owned dogs on 2-3 occasions spanning 24 months and they underwent whole genome shotgun (WGS) sequencing. Cognitive status was established at each sampling time. A statistically significant increase in alpha diversity for bacterial and fungal species was observed between the first and last study visits. Bacteroidetes and proteobacteria were the most abundant bacterial phyla. Porphyromonas gulae was the most abundant bacterial species (11.6% of total reads). The species Lactobacillus gasseri had a statistically significant increase in relative abundance with age whereas Leptotrichia sp. oral taxon 212 had a statistically significant positive longitudinal association with cognition score. There is an increased fungal and bacterial alpha diversity in aging dogs over time and nearly universal oral dysbiosis. The role of the oral microbiota, particularly Leptotrichia and P. gulae and P. gingivalis, in aging and CCDS warrants further investigation.

Veterinary education and experience shape beliefs about dog breeds Part 1: Pain sensitivity.

Over 95% of veterinarians report believing that dog breeds differ in pain sensitivity. Ratings made by veterinarians differ from those of the general public, suggesting these beliefs may be learned during veterinary training or clinical experiences. Therefore, the current study's primary objective was to evaluate dog breed pain sensitivity ratings during veterinary training and compare these ratings to those of the general public and undergraduates in animal-health related fields. Using an online survey, members of the general public, undergraduates, veterinary students across all four years, and veterinary faculty and staff rated pain sensitivity of 10 different dog breeds, identified only by their pictures. Compared to the general public and undergraduates, veterinary students rated pain sensitivity across breeds of dog more similarly to veterinary faculty and staff. Further, when undergraduates had clinical experience, they also rated certain dog breeds in a similar way to the veterinary students and professionals. Our findings suggest that veterinary education and clinical experiences influence pain sensitivity ratings across dog breeds. Future research should identify how these pain sensitivity beliefs are communicated and whether these beliefs affect recognition and treatment of pain by veterinarians.

Veterinary education and experience shape beliefs about dog breeds. Part 2: Trust.

Dog breed stereotypes are frequently used to inform people's expectations about canine behavior, despite evidence that breed is largely uninformative in predicting individual dog behavior. Further, these beliefs differ among populations. However, it remains unknown how ratings of warmth toward a breed are associated with ratings of other social behavioral domains, and whether differences exist between populations with varying experience with dogs. The purpose of this study was to evaluate ratings of trust and warmth among survey respondents including veterinary students, veterinary faculty and staff, undergraduates in animal-health related majors and members of the general public. Using an online survey, respondents rated their likelihood to trust a dog in varying scenarios for 10 different dog breeds. Additionally, respondents used a feelings thermometer to rate how warm or cool they felt towards each breed. Findings revealed differences in feelings thermometer and trust ratings across populations. All ratings were lower among the veterinary academic respondents compared to the general public and undergraduates. Veterinary students further along in their training, as well as undergraduates with clinical experience, reflected perceptions similar to those of the veterinary faculty and staff providing support for cultural transmission of beliefs during veterinary education and training.

Pain sensitivity differs between dog breeds but not in the way veterinarians believe.

Background: Veterinarians hold distinct breed-specific pain sensitivity beliefs that differ from the general public but are highly consistent with one another. This is remarkable as there is no current scientific evidence for biological differences in pain sensitivity across dog breeds. Therefore, the present study evaluated whether pain sensitivity thresholds differ across a set of dog breeds and, if so, whether veterinarians' pain sensitivity ratings explain these differences or whether these ratings are attributed to behavioral characteristics. Methods: Pain sensitivity thresholds [using quantitative sensory testing (QST) methods] and canine behaviors (using owner questionnaires and emotional reactivity tests) were prospectively measured across selected dog breeds. Adult, healthy dogs from 10 dog breeds/breed types were recruited, representing breeds subjectively rated by veterinarians as high (chihuahua, German shepherd, Maltese, Siberian husky), average (border collie, Boston terrier, Jack Russell terrier), or low (golden retriever, pitbull, Labrador retriever) pain sensitivity. A final sample of 149 dogs was included in statistical analyses. Results: Veterinarians' pain sensitivity ratings provided a minimal explanation for pain sensitivity thresholds measured using QST in dogs; however, dog breeds did differ in their pain sensitivity thresholds across the QST methods evaluated. Breed differences were observed for some aspects of emotional reactivity tests; however, these behavioral differences did not explain the differences in pain sensitivity thresholds found. Veterinarians' pain sensitivity ratings were positively associated with dog approach scores for the disgruntled stranger test suggesting that the way dogs greet strangers may be a factor influencing veterinarians' ratings of pain sensitivity across dog breeds. Conclusions and clinical relevance: Overall, these findings highlight a need to investigate biological mechanisms that may explain breed differences in pain sensitivity because this may inform pain management recommendations. Further, future research should focus on when and how these breed-specific pain sensitivity beliefs developed in veterinarians, as veterinarians' beliefs could impact the recognition and treatment of pain for canine patients.

Winning the race with aging: age-related changes in gait speed and its association with cognitive performance in dogs.

Introduction: In humans, gait speed is a crucial component in geriatric evaluation since decreasing speed can be a harbinger of cognitive decline and dementia. Aging companion dogs can suffer from age-related mobility impairment, cognitive decline and dementia known as canine cognitive dysfunction syndrome. We hypothesized that there would be an association between gait speed and cognition in aging dogs. Methods: We measured gait speed on and off leash in 46 adult and 49 senior dogs. Cognitive performance in senior dogs was assessed by means of the Canine Dementia Scale and a battery of cognitive tests. Results: We demonstrated that dogs' food-motivated gait speed off leash is correlated with fractional lifespan and cognitive performance in dogs, particularly in the domains of attention and working memory. Discussion: Food-motivated gait speed off leash represents a relatively easy variable to measure in clinical settings. Moreover, it proves to be a more effective indicator of age-related deterioration and cognitive decline than gait speed on leash.

Age-associated changes in electroretinography measures in companion dogs.

PURPOSE: To determine the association between age and retinal full-field electroretinographic (ERG) measures in companion (pet) dogs, an important translational model species for human neurologic aging. METHODS: Healthy adult dogs with no significant ophthalmic abnormalities were included. Unilateral full-field light- and dark-adapted electroretinography was performed using a handheld device, with mydriasis and topical anaesthesia. Partial least squares effect screening analysis was performed to determine the effect of age, sex, body weight and use of anxiolytic medication on log-transformed ERG peak times and amplitudes; age and anxiolytic usage had significant effects on multiple ERG outcomes. Mixed model analysis was performed on data from dogs not receiving anxiolytic medications. RESULTS: In dogs not receiving anxiolytics, median age was 118 months (interquartile range 72-140 months, n = 77, 44 purebred, 33 mixed breed dogs). Age was significantly associated with prolonged peak times of a-waves (dark-adapted 3 and 10 cds/m2 flash p < 0.0001) and b-waves (cone flicker p = 0.03, dark-adapted 0.01 cds/m2 flash p = 0.001). Age was also significantly associated with reduced amplitudes of a-waves (dark-adapted 3 cds/m2 flash p < 0.0001, 10 cds/m2 flash p = 0.005) and b-waves (light-adapted 3 cds/m2 flash p < 0.0001, dark-adapted 0.01 cds/m2 flash p = 0.0004, 3 cds/m2 flash p < 0.0001, 10 cds/m2 flash p = 0.007) and flicker (light-adapted 30 Hz 3 cds/m2 p = 0.0004). Within the Golden Retriever breed, these trends were matched in a cross-sectional analysis of 6 individuals that received no anxiolytic medication. CONCLUSIONS: Aged companion dogs have slower and reduced amplitude responses in both rod- and cone-mediated ERG. Consideration of anxiolytic medication use should be made when conducting ERG studies in dogs.

Sleep and cognition in aging dogs. A polysomnographic study.

Introduction: Sleep is fundamental for cognitive homeostasis, especially in senior populations since clearance of amyloid beta (key in the pathophysiology of Alzheimer's disease) occurs during sleep. Some electroencephalographic characteristics of sleep and wakefulness have been considered a hallmark of dementia. Owners of dogs with canine cognitive dysfunction syndrome (a canine analog to Alzheimer's disease) report that their dogs suffer from difficulty sleeping. The aim of this study was to quantify age-related changes in the sleep-wakefulness cycle macrostructure and electroencephalographic features in senior dogs and to correlate them with their cognitive performance. Methods: We performed polysomnographic recordings in 28 senior dogs during a 2 h afternoon nap. Percentage of time spent in wakefulness, drowsiness, NREM, and REM sleep, as well as latency to the three sleep states were calculated. Spectral power, coherence, and Lempel Ziv Complexity of the brain oscillations were estimated. Finally, cognitive performance was evaluated by means of the Canine Dementia Scale Questionnaire and a battery of cognitive tests. Correlations between age, cognitive performance and sleep-wakefulness cycle macrostructure and electroencephalographic features were calculated. Results: Dogs with higher dementia scores and with worse performance in a problem-solving task spent less time in NREM and REM sleep. Additionally, quantitative electroencephalographic analyses showed differences in dogs associated with age or cognitive performance, some of them reflecting shallower sleep in more affected dogs. Discussion: Polysomnographic recordings in dogs can detect sleep-wakefulness cycle changes associated with dementia. Further studies should evaluate polysomnography's potential clinical use to monitor the progression of canine cognitive dysfunction syndrome.

A novel task of canine olfaction for use in adult and senior pet dogs.

While much work has been done in the field of canine olfaction, there has been little exploration of hyposmia or anosmia. This is partly due to difficulties in reducing confounds like training history and environmental distraction. The current study describes a novel olfaction test using spontaneous search behavior in dogs to find a hidden food treat in a three-choice task with both light-phase and dark-phase conditions. The study was performed in 18 adult control dogs, 18 senior/geriatric dogs enrolled in a longitudinal aging study, and a single dog with severe nasal pathology. In the senior/geriatric and control groups, dogs performed with higher accuracy (p < 0.0001) and were less likely to show biased selection strategy (p < 0.01) in the dark-phase than light-phase. While senior/geriatric dogs performed above chance, they had lower accuracy in the dark-phase compared to controls (p = 0.036). Dogs who scored higher on an owner questionnaire of cognitive decline showed a positive correlation with performance in the dark-phase; performance on additional cognitive tests did not correlate with performance in the dark-phase. This task can be used to quantify canine olfaction using clearly defined endpoints and spontaneous behaviors thus making it feasible to compare between and within groups of pet dogs.

Activity patterns are associated with fractional lifespan, memory, and gait speed in aged dogs.

Maintaining an active lifestyle is considered a hallmark of successful aging. Physical activity significantly reduces the risk of cognitive decline and Alzheimer's disease in humans. However, pain and lack of motivation are important barriers to exercise. Dogs are a remarkable model for translational studies in aging and cognition as they are prone to Canine Cognitive Dysfunction syndrome, which has many similarities with Alzheimer's disease. According to owner reports, changes in activity levels are characteristic of this syndrome, with decreased daytime activity, but also excessive pacing, especially at sleep time. We used physical activity monitors to record the activity of 27 senior dogs and evaluated the association between activity level and age, fractional lifespan, cognitive status measured by an owner questionnaire and cognitive tests. We also assessed the relationship between activity and joint/spinal pain, and the off/on leash gait speed ratio (a potential marker of gait speed reserve and motivation). We found that activity patterns in dogs are associated with fractional lifespan and working memory. Additionally, dogs with higher on/off leash gait speed are more active in the afternoon of weekdays. These results encourage future studies evaluating how physical activity can improve or delay cognitive impairment in senior dogs.

Response to Hansen Wheat et al.: Additional analysis further supports the early emergence of cooperative communication in dogs compared to wolves raised with more human exposure.

Here, we address Hansen Wheat et al.'s commentary in this journal in response to Salomons et al. Current Biology, 31(14), 3137-3144.E11, (2021). We conduct additional analyses in response to Hansen Wheat et al.'s two main questions. First, we examine the claim that it was the move to a human home environment which enabled the dog puppies to outperform the wolf puppies in gesture comprehension tasks. We show that the youngest dog puppies who had not yet been individually placed in raisers' homes were still highly skilled, and outperformed similar-aged wolf puppies who had higher levels of human interaction. Second, we address the claim that willingness to approach a stranger can explain the difference between dog and wolf pups' ability to succeed in gesture comprehension tasks. We explain the various controls in the original study that render this explanation insufficient, and demonstrate via model comparison that the covariance of species and temperament also make this parsing impossible. Overall, our additional analyses and considerations support the domestication hypothesis as laid out by Salomons et al. Current Biology, 31(14), 3137-3144.E11, (2021).

A Literature Review: Pet Bereavement and Coping Mechanisms.

The loss of a companion animal results in millions of pet owners grieving annually. To date, little information has been synthesized on the grief response and coping mechanisms of bereaved pet owners. The aim of this review was to examine the relationship between pet loss and owner grief response. Major themes included: factors that influence the grief response, the disenfranchised nature surrounding pet loss, ambiguous pet loss and coping mechanisms used. Across the 48 studies included in this review, bereaved pet owners frequently reported feelings of embarrassment and loneliness following the loss of their pet. Types of coping mechanisms used by bereaved pet owners were identified and included: isolation, social support, continuing bonds, memorialization, religion, and relationships with other animals. Overall, this review was able to identify a consensus among the literature that bereaved pet owners are likely to experience disenfranchisement surrounding their loss. Based on the present findings, suggestions for future research include a focus on the effectiveness of coping mechanisms used by bereaved pet owners.

Relationship between hearing, cognitive function, and quality of life in aging companion dogs.

BACKGROUND: Elderly people with presbycusis are at higher risk for dementia and depression than the general population. There is no information regarding consequences of presbycusis in dogs. OBJECTIVE: Evaluate the relationship between cognitive function, quality of life, and hearing loss in aging companion dogs. ANIMALS: Thirty-nine elderly companion dogs. METHODS: Prospective study. Hearing was evaluated using brainstem auditory evoked response (BAER) testing. Dogs were grouped by hearing ability. Owners completed the canine dementia scale (CADES) and canine owner-reported quality of life (CORQ) questionnaire. Cognitive testing was performed, and cognitive testing outcomes, CADES and CORQ scores and age were compared between hearing groups. RESULTS: Nineteen dogs could hear at 50 dB, 12 at 70 dB, and 8 at 90 dB with mean ages (months) of 141 ± 14, 160 ± 16, and 172 ± 15 for each group respectively (P = .0002). Vitality and companionship CORQ scores were significantly lower as hearing deteriorated (6.6-5.4, 50-90 dB group, P = .03 and 6.9-6.2, 50-90 dB group, P = .02, respectively). Cognitive classification by CADES was abnormal in all 90 dB group dogs and normal in 3/12 70 dB group and 11/19 50 dB group dogs (P = .0004). Performance on inhibitory control, detour and sustained gaze tasks decreased significantly with hearing loss (P = .001, P = .008, P = .002, respectively). In multivariate analysis, higher CADES score was associated with worse hearing (P = .01). CONCLUSIONS AND CLINICAL IMPORTANCE: Presbycusis negatively alters owner-pet interactions and is associated with poor executive performance and owner-assessed dementia severity.

Static posturography as a novel measure of the effects of aging on postural control in dogs.

Aging is associated with impairment in postural control in humans. While dogs are a powerful model for the study of aging, the associations between age and postural control in this species have not yet been elucidated. The aims of this work were to establish a reliable protocol to measure center of pressure excursions in standing dogs and to determine age-related changes in postural sway. Data were obtained from 40 healthy adult dogs (Group A) and 28 senior dogs (Group B) during seven trials (within one session of data collection) of quiet standing on a pressure sensitive walkway system. Velocity, acceleration, root mean square, 95% ellipse area, range and frequency revolve were recorded as measures of postural sway. In Group A, reliability was assessed with intraclass correlation, and the effect of morphometric variables was evaluated using linear regression. By means of stepwise linear regression we determined that root mean square overall and acceleration in the craniocaudal direction were the best variables able to discriminate between Group A and Group B. The relationship between these two center-of-pressure (COP) measures and the dogs' fractional lifespan was examined in both groups and the role of pain and proprioceptive deficits was evaluated in Group B. All measures except for frequency revolve showed good to excellent reliability. Weight, height and length were correlated with most of the measures. Fractional lifespan impacted postural control in Group B but not Group A. Joint pain and its interaction with proprioceptive deficits influence postural sway especially in the acceleration in the craniocaudal direction, while fractional lifespan was most important in the overall COP displacement. In conclusion, our study found that pressure sensitive walkway systems are a reliable tool to evaluate postural sway in dogs; and that postural sway is affected by morphometric parameters and increases with age and joint pain.