Common physical and functional changes associated with aging in dogs

Morphological comparative study of canine and feline diaphragms: Effect of bodyweight, body condition score, gender, age and breed

The canine diaphragm is a muscular and tendinous dome-like plate and is largely involved in digestive and respiratory functions. Very few studies compared morphology of the diaphragm between dogs and cats and no studies have investigated the effects of individual factors on this morphology. So the aim of this study was to (1) study the effects of individual factors on the morphology of the diaphragm and (2) to compare its morphology between cats and dogs. Surface measurements of 86 diaphragms were performed. The tendinous centre (TC), the lumbar part of the peripheral muscular (LP) and the sternal and costal parts of the peripheral muscular (SCPM) were measured. Measurement ratios (surface of anatomical part of the diaphragm/total surface of the diaphragm) were used for statistical analysis (TC%S, LP%S, SCPM%S). The SCPM%S are significantly lower, and the LP%S are significantly higher when bodyweight increases in dogs and cats. The TC%S are significantly lower when the body condition score of dogs increases. The SCPM%S are significantly higher, and therefore, the TC%S and LP%S lower in brachycephalic animals as opposed to mesocephalic animals. The TC%S are significantly higher in dogs than in cats and the SCPM%S are significantly higher in cats than in dogs. This study proposed a cartography of the diaphragm morphology in cats and dogs taking into account individual animal factors. Significant differences in the diaphragm morphology between cats and dogs and between mesocephalic and brachycephalic animals were found. Further studies are necessary to confirm these results and to investigate the consequences of these variations.

Proteomic analysis of the serum in dogs with pulmonary hypertension secondary to myxomatous mitral valve disease: the preliminary study

Background

Pulmonary hypertension (PH) is a common complication in dogs with myxomatous mitral valve disease (MMVD), characterized by elevated blood pressure in pulmonary artery. Echocardiography is a reliable technique for PH diagnosis in veterinary medicine. However, it is limited to use as an early detection method. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) has found extensive application in the discovery of serum protein biomarkers for various diseases. The objective of this study was to identify serum proteins in healthy control dogs and MMVD dogs both with and without PH using LC-MS/MS.

Materials and methods

In this research, a total of 81 small-breed dogs participated, and they were categorized into three groups: the control (n = 28), MMVD (n = 24) and MMVD+PH (n = 29) groups. Serum samples were collected and analyzed by LC-MS/MS.

Results

Differentially expressed proteins were identified, and the upregulated and downregulated proteins in MMVD+PH group including Myomesin 1 (MYOM1) and Histone deacetylase 7 (HDAC7), Pleckstrin homology domain containing M3 (PLEKHM3), Diacylglycerol lipase alpha (DAGLA) and Tubulin tyrosine ligase like 6 (TTLL6) were selected as proteins of interest in MMVD dogs with PH.

Conclusion

Different types of proteins have been identified in healthy dogs and MMVD dogs with and without PH. Additional studies are needed to investigate the potential of these proteins as biomarkers for PH in dogs with MMVD.

Development and Validation of a Novel Instrument to Capture Companion Dog Mortality Data: The Dog Aging Project End of Life Survey

Objective

The researchers and clinicians within the Dog Aging Project (DAP), a longitudinal cohort study of aging in companion dogs, created and validated a novel survey instrument titled the End of Life Survey (EOLS) to gather owner-reported mortality data about companion dogs.

Sample

Bereaved dog owners who participated in the refinement, face validity assessment, or reliability assessment of the EOLS (n=42) and/or completed the entire survey between January 20 and March 24, 2021 (n=646).

Procedures

The EOLS was created and modified by veterinary health professionals and human gerontology experts using published literature, clinical veterinary experience, previously created DAP surveys, and feedback from a pilot study conducted with bereaved dog owners. The EOLS was subjected to qualitative validation methods and post-hoc free-text analysis to evaluate its ability to thoroughly capture scientifically relevant aspects of companion dogs' death.

Results

The EOLS was well-received with excellent face validity as assessed by dog owners and experts. The EOLS had fair to substantial reliability for the three validation themes: cause of death (kappa = 0.73; 95% CI [0.5-0.95]), perimortem quality of life (kappa = 0.49; 95% CI [0.26-0.73]), and reason for euthanasia (kappa = 0.3; 95% CI [0.08-0.52]) and had no need for any substantial content alterations based on free-text analysis.

Clinical Relevance

The EOLS has proven to be a well-accepted, comprehensive, and valid instrument for capturing owner-reported companion dog mortality data and has the potential to enhance veterinarians' ability to care for the aging dog population by illuminating their understanding of companion dogs' end-of-life experiences.

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.

Refractive errors in mixed breed dogs of different ages

The purpose of the study was to evaluate the occurrence and range of refractive errors in dogs of different ages. A total of 99 clinically healthy, mixed-breed mesocephalic dogs were included in the study and divided into three different age groups according to the current human/pet analogy chart: 40 adults (23 males, 17 females, 1-8 years old, 3-70 kg), 21 seniors (14 males, 7 females, 6-11 years old, 7-42 kg), and 38 geriatrics (22 males, 16 females, 8-13 years old, 5-45 kg). All the dogs underwent an ophthalmic examination, including Schirmer tear test, tonometry, biomicroscopy, and ophthalmoscopy. Neither eye drops nor pharmacological sedatives were administered before the autorefractometry. The refractive states were assessed bilaterally using a hand-held Retinomax 3 (Righton) autorefractor. The results underwent statistical analysis using Statistica v12 software (ANOVA and t-test). A P-value < 0.05 was considered as significant. Emmetropia, defined as a refractive state > -0.5 D and < +0.5 D, was found in 36% of the adult, 43% of the senior, and 38% of the geriatric patients. Anisometropia was found in 1% of the adult, 9.5% of the senior and 5.5% of the geriatric dogs when the refractive power of the two eyes differed ≥ 1.0 myopia ≤ -0.5 D and hyperopia ≥ +0.5 D were found in 23% and 41% of the adult eye globes as well as 24% and 33% in the senior dogs and 15% and 47% in the geriatric dogs, respectively. The maximal values of the myopia in the adult and geriatric dogs were -2.5 D and -2.75 D, respectively. The maximal values of the hyperopia in the adult and geriatric dogs were 1.75 D and 2.5 D, respectively. No statistically significant correlation was found between the groups. Ametropia is a common refractive state for dogs of different ages. The most frequent refractive state in ametropic mixed-bed dogs in all age groups is hyperopia.

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.

Neurogenic Bladder in Dogs, Cats and Humans: A Comparative Review of Neurological Diseases

Lower urinary tract disease (LUTD) includes abnormalities in the structure and function of the bladder and the urethra. LUTD caused by neurological disease is defined neurogenic bladder (NB). The integrity of the central nervous system (CNS) and peripheral nervous system (PNS) is required to explicate normal micturition, maintaining the proper function of bladder and urethra. The location and type of neurological lesions influence the pattern of clinical manifestations, potential treatment, and prognosis. Though, in dogs and cats, spinal cord injury is considered mainly responsible for bladder and/or urethra incompetence, other disorders, congenital or acquired, involving CNS or PNS, could play a role in NB. In veterinary medicine, the information about the epidemiology, prevalence, etiopathogenesis, diagnosis and treatment of NB are scattered. The aim of this study is to provide an overview of the epidemiology, prevalence, clinical findings, diagnosis and prognosis for NB in dogs and cats compared with humans.

Two valid and reliable tests for monitoring age-related memory performance and neophobia differences in dogs

The prolonged lifespan of companion dogs has resulted in increased behavioural and physical challenges linked to old age. The development of behavioural tests to identify and monitor age-related differences has begun. However, standardised testing requires validation. The present study aimed to assess external validity, interobserver reliability, and test-retest reliability of an indoor test battery for the rapid assessment of age-related behavioural differences in dogs. Two experimenters tested young dogs (N = 20, mean age ± SD = 2.7 ± 0.4 years) and old dogs (N = 18, mean age ± SD = 11.8 ± 1.3 years) in the test battery once and then again after two weeks. Our results found external validity for two subtests out of six. On both test occasions, old dogs committed more errors than young dogs in a memory subtest and showed more object avoidance when encountering a novel object. Interobserver reliability and test-retest reliability was high. We conclude that the Memory and Novel object subtests are valid and reliable for monitoring age-related memory performance and object neophobic differences in dogs.

[A multifactorial risk index for evaluation of anesthetic risk in dogs: the LeiV-Risk-Index]

OBJECTIVE

The Leipzig Veterinary Risk-Index - "LeiV-Risk-Index" is a multifactorial risk index developed to enable an improved objective assessment of the anesthetic risk in dogs. The scoring system is based on 10 risk factors affecting perioperative mortality. The aim of this study was to evaluate the applicability of the LeiV-Risk-Index and its risk factors as well as to perform a direct comparison with the ASA-classification.

MATERIAL AND METHODS

An online survey was conducted among veterinarians working in small animal medicine throughout Germany. Participants received a questionnaire containing information on 15 selected patients. They were asked to classify the patients according to the LeiV-Risk-Index and ASA-classification and to answer several questions concerning their professional background. The results were statistically analyzed considering the consistency among veterinarians of rating the different patients by using Fleiss'-Kappa. The correlation of LeiV-Risk-Index and ASA-classification was calculated.

RESULTS

The consistency of all assigned LeiV-risk classes between participants was moderate (κ = 0.55) and higher than classification by ASA (κ = 0.33). On average, 3 different LeiV-risk classes and 4 different ASA-classes were assigned for one patient. There was a positive correlation between LeiV-risk class and increasing ASA-class. No effect of gender or clinical experience of the veterinarian could be demonstrated on ranking patients. There was also no effect of how confident veterinarians felt in applying the LeiV-Risk-Index.

CONCLUSION UND CLINICAL RELEVANCE

The LeiV-Risk-Index is the first index available in veterinary medicine for assessing anesthetic risk that is based on objective risk criteria and whose objectivity exceeds that of the ASA classification. Anesthetic patients can thus be evaluated more consistently in veterinary medicine as well. Utility and practicability were positively received by 95 % of the participants. Further revision of individual risk criteria needs to be reconsidered.

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.

Frozen-Thawed Sperm Analysis of Benign Prostatic Hyperplasia Dogs Treated With Finasteride

Benign Prostatic Hyperplasia (BPH) is a pathological condition that directly interferes with the reproductive potential of senile dogs, by leading to prostate enlargement and sperm injury, which in turn may compromise sperm freezeability. Moreover, albeit finasteride treatment reduces prostatic volume and blood supply and maintains seminal quality and testicular integrity, the effects of sperm samples submitted to cryopreservation after the finasteride treatment are still unknown. Thus, the aim of this study was to evaluate frozen-thawed semen of BPH dogs, as well as dogs subjected to BPH pharmacological treatment with finasteride. For such purpose, 20 dogs were previously selected and assigned to three experimental groups, according to BPH diagnosis and treatment with finasteride: Control (n = 9), BPH Group (n = 5) and BPH-Finasteride Group (n = 6). Semen was subjected to one-step cryopreservation protocol with tris-fructose-citric acid extender with 5% glycerol and thawed at 37°C for 30 sec. Fresh and post-thaw sperm samples were evaluated for macroscopic parameters, sperm concentration, sperm motility kinetics, sperm mitochondrial activity and potential, oxidative stress, plasmatic and acrosome membrane integrity, sperm DNA fragmentation and sperm binding test on perivitelic membrane of chicken egg yolk. Regarding fresh semen, BPH-Finasteride group had the lowest ejaculate visual aspect (opacity), higher frequency of sperm flagellar beating (BCF) and percentage of sperm with medium velocity. Control group had the highest percentage of sperm DNA integrity compared to BPH group. For the frozen-thawed semen, Control group presented the highest percentage of spermatozoa with high mitochondrial activity. However, the BPH-Finasteride group showed higher number of sperm bound to the perivitelline membrane of chicken egg yolk compared to the BPH Group. Conversely, BPH group had higher percentage of DNA damage. In conclusion, the ejaculate of BPH dogs has higher susceptibility to cryoinjury, whereas finasteride-treated dogs have increased spermatozoa functional performance, suggesting a promising use of BPH dogs as semen donors in sperm cryopreservation programs.

Canine Mobility Maintenance and Promotion of a Healthy Lifestyle

This article highlights the recommendations and considerations for maintaining a healthy canine lifestyle. A key component of a healthy lifestyle is the enhancement and optimization of mobility. Mobility is essential in maintaining a high quality of life and involves the interplay of a dog's structure, posture, body condition score, physical exercise, and a healthy human-animal bond throughout a dog's lifetime.

The phenotype of aging in the dog: how aging impacts the health and well-being of dogs and their caregivers

Aging is the single most important cause of disease, disability, and death in adult dogs. Contrary to the common view of aging as a mysterious and inevitable natural event, it is more usefully understood as a set of complex but comprehensible biological processes that are highly conserved across species. Although the phenotypic expression of these processes is variable, there are consistent patterns both within and between species.

The purpose of this feature is to describe the patterns currently recognized in the physical and behavioral manifestations of aging in the dog and how these impact the health and welfare of companion dogs and their human caregivers. Important gaps in our knowledge of the canine aging phenotype will be identified, and current research efforts to better characterize aging in the dog will be discussed. This will help set the context for future efforts to develop clinical assessments and treatments to mitigate the negative impact of aging on dogs and humans.

Canine Geriatric Rehabilitation: Considerations and Strategies for Assessment, Functional Scoring, and Follow Up

Geriatric animals account for half of the pet population in the United States with their numbers increasing annually. Furthermore, a significant percentage of veterinary patients with movement limitations could be grossly categorized as geriatric and living within the end stage of their predicted lifespans. Because mobility is correlated to quality of life and time to death in aging dogs, a major goal in optimizing canine geriatric health is to improve functional movement. Within the geriatric population, identifying disabilities that affect daily living and quality of life may be used by the rehabilitation practitioner to provide stronger prognoses, treatment goals, and outcome measures. Examples of such means are described within this review. In human medicine, the concept of “optimal aging”, or “healthy aging”, has emerged in which inevitable detrimental age-related changes can be minimized or avoided at various levels of physical, mental, emotional, and social health. Both environment and genetics may influence aging. Identifying and improving environmental variables we can control remain a key component in optimizing aging. Furthermore, diagnosing and treating age related comorbidities common to older populations allows for improved quality of life and is often directly or indirectly affecting mobility. Obesity, sarcopenia, and a sedentary lifestyle are a trifecta of age-related morbidity common to both people and dogs. Healthy lifestyle choices including good nutrition and targeted exercise play key roles in reducing this morbidity and improving aging. Disablement models act as essential tools for creating more effective physiotherapy plans in an effort to counter dysfunction and disability. Within these models, functional testing represents a standard and validated means of scoring human geriatric function as well as monitoring response to therapy. Because of the great need in dogs, this review aims to provide a reasonable and testable standardized framework for canine functional scoring. We believe a complete assessment of canine geriatric patients should comprise of identifying environmental variables contributing to health status; diagnosing comorbidities related to disease and aging; and characterizing disability with standardized methods. Only through this process can we construct a comprehensive, reasonable, and targeted rehabilitation plan with appropriate follow up aimed at healthy aging.

Occurrence of Dirofilaria immitis in Stray Dogs from Nepal

BACKGROUND

Nematodes of the genus Dirofilaria are widespread vector-borne helminths (VBH) of veterinary relevance. Dirofilariosis caused by D. immitis is frequently diagnosed in dogs often showing a severe clinical condition known as heartworm disease. Assessing the distribution pattern of canine dirofilariosis is pivotal to undertake appropriate control measures and define the risk of infection in animals and humans. This study provides original data on the occurrence of D. immitis in naive stray dogs from Nepal.

METHODS

An epidemiological study was performed on stray dogs from Siddharthanagar, Lumbini region, Nepal. Alive animals were blood sampled and examined for microfilariae using direct microscopy, buffy coat centrifugation and modified Knott's method. In addition, hematobiochemical parameters, including packed cell volume (PCV), alanine aminotransferase (SGPT), aspartate aminotransferase (SGOT), alkaline phosphate (ALP), creatinine, blood urea nitrogen (BUN), urea and total protein were analysed, along with a clinical scoring (body temperature and respiratory rate). During the observation period, data on autopsies performed on stray dogs showing canine heartworm disease were also included.

RESULTS

The overall prevalence of D. immitis in both alive and necropsied dogs was 22.49% (38/169). Out of 150 alive dogs, 29 (19.3%) were positive for D. immitis microfilariae. The prevalence of the infection varied according to the technique used, ranging from 16.0 to 19.3% based on direct blood smear microscopy and modified Knott's technique, respectively. The infection rate was significantly higher (p < 0.05) in dogs aging more than 3 years. A positive correlation was observed between SGPT and SGOT and the presence of microfilariae (p < 0.05). Among the 19 dead stray dogs, 9 animals showed adult D. immitis nematodes.

CONCLUSION

Results of this survey account for the presence of D. immitis in stray dogs from Nepal, thus supporting the existence of a local transmission cycle of diroflariosis in the region. Further investigations are warranted to accurately define the prevalence of the infection in the canine population and to undertake appropriate control measures to reduce the burden on the infection in dogs and, accordingly, the risk of transmission to humans.

Age-related digestibility of nutrients depending on the moisture content in aged dogs

Digestibility of pet food can affect the health of dog, especially of aged animals. To maintain the health of dogs in an overall good status it is necessary to provide nutritionally balanced food. For example, the digestibility of dogs was known to be decreased along aging. In addition, losing teethes is an often event in aged dogs that could induce a problem to eat a large size dry pet food. Nonetheless, few detailed information is available on the most suited feeding for aged dogs. As part of the nutritional study of food for aged dogs, in this study, we tested whether food type impacts on digestibility on adult versus senior dogs. The methodology to measure the digestibility of nutrients was chosen the index method using chromium oxide. Dogs were fed the same commercial dry or wet diets, which were supplemented with 0.5% chromium oxide. The wet food was prepared by adding twice volume of water in the dry food prior to incubated overnight (14-16 hours) at room temperature. After five days, their feces were collected up to a total weight of > 200 g which was the amount to analyze undigested nutrients in feces as 3 repeats. In the apparent total tract digestibility analysis of the experimental breed, no difference in the digestibility of crude protein, crude fat, crude fiber, ash, and energy was observed regarding the moisture content of the food. Noteworthy, the digestibility of nitrogen free extract was significantly increased in senior dogs fed dry dog food compared with adult dogs fed the same diet, whereas no difference was observed between senior and adult dogs fed wet food. The small breed dogs showed similar results to the experimental breed dogs. However, the digestibility of crude fat was additionally affected by age and food type unlike the experimental breed dogs. This finding suggests that the food moisture content affects the digestibility of nutrients in dogs with aging. Hence, it may be helpful to determine the nutrient contents in foods for senior dogs depending on the food type.

Reasons for Exclusion of Apparently Healthy Mature Adult and Senior Dogs From a Clinical Trial

Background: Interventional clinical trials intended to maintain health in aging dogs are unusual and require particular attention to exclusion criteria.

Objectives: To describe reasons for exclusion when a mature adult and senior canine population with normal health status was sought.

Animals: Fifty six companion dogs nominated for a randomized controlled trial (RCT).

Procedures: Exclusions occurred within Stage 1 (S1): owner-provided survey information; Stage 2 (S2): medical records review; and Stage 3 (S3): screening examination and within Owner, Dog, or Other factor categories.

Results: Of 56 nominated dogs, 39 were excluded at S1 (n = 19), S2 (n = 5), and S3 (n = 15), respectively. Dogs were excluded for Owner (n = 4), Dog (n = 27), Other (n = 6), and concurrent (Owner + Dog; n = 2) factors. The most common exclusion period was S1 (n = 19), with weight outside the target range being the most common exclusion factor in that stage (n = 10). Heart murmurs were the second most common exclusion factor (S1: n = 1; S3: n = 5); suspected or confirmed systemic illness was third most common (S1: n = 2; S2: n = 3; S3: n = 2). Among dogs who passed S1 and S2 screening (n = 32), 15 dogs (48%) were excluded at S3, for heart murmur > grade II/VI (n = 5), cardiac arrhythmias (n = 2), and clinicopathologic abnormalities (n = 2).

Conclusions and Clinical Relevance: Dogs nominated for a clinical trial for healthy mature adult and senior dogs were excluded for size, previous diagnoses, and newly discovered cardiac abnormalities. For future interventions in mature adult and senior dogs of normal health status, it is important to define expected age-related abnormalities to ensure that meaningful exclusion criteria are used.

TeamMate: A Longitudinal Study of New Zealand Working Farm Dogs. III. Factors Affecting the Risk of Dogs Being Lost from the Workforce

Working farm dogs are essential to many livestock farmers. Little is known about factors that influence dogs' risk of being lost from work. This paper explores risk factors for farm dogs being lost through death, euthanasia and retirement. All enrolled dogs were working and a minimum of 18 months old. Five data collection rounds were performed over four years. Data about dogs were collected from owners and dogs were given physical examinations by veterinarians. Dogs that were lost from work were counted and owner-reported reasons for loss were recorded. Multivariable logistic regression modelling was used to investigate risk factors for loss. Of 589 dogs, 81 were lost from work. Of these, 59 dogs died or were euthanized and 22 were retired. Farm dogs tended to reach advanced ages, with 38% being 10 years or older when last examined. Acute injury or illness was the most commonly owner-reported reason for loss. Age group (p < 0.0001) and lameness (p = 0.04, OR = 1.8) significantly affected dogs' risk of being lost. These results expand our knowledge about factors that affect health, welfare and work in farm dogs. Further investigation into reasons for lameness may help improve health and welfare in working farm dogs.

Use of the Milan Pet Quality of Life Instrument (MPQL) to Measure Pets' Quality of Life during COVID-19

Simple Summary

COVID-19 caused unprecedented lifestyle changes, with unknown effects on pets’ quality of life. We studied the role of personality, the human–animal relationship, COVID-19-related factors, and demographics on feline and canine quality of life (QoL). We used the novel Milan Pet Quality of Life instrument (MPQL), derived from previous scales, which summarises four QoL domains: physical, psychological, social, and environmental. Our findings indicate that pets’ demographics, life experience, and personality could explain a large part of the physical QoL. Conversely, the owners’ demographics, COVID-19-related changes, and the owners’ personality mostly explained the pets’ psychological QoL. Predictably, outdoor access in the home environment and the country of residence mostly explained the pets’ environmental QoL. Finally, the pets’ social QoL was explained by all previous aspects: pets’ characteristics and personality, environment and COVID-19-related changes, and the pet–human relationship. We suggest that these results may be explained by the effects of the COVID-19 pandemic on the owners’ psychological state and lifestyle, which in turn alter the way the owners interact with their pets and look after them. However, the owners’ personality and mood may also influence the way they interpret and report their pets’ behavior and emotional state. These findings highlight the importance of the One Health–One Welfare perspective.

Abstract

The COVID-19 pandemic caused lifestyle changes, with unknown effect on pets’ quality of life (QoL). Between May and July 2020, we distributed an online survey to investigate the role of several factors on feline and canine QoL, including lockdown-related factors. We used existing scales to measure human and pets’ personalities (Reinforcement Sensitivity Theory Personality Questionnaire, RST-PQ; RST-Dog; RST-Cat) and the human–animal relationship (Lexington Attachment to Pets Scale, LAPS) and the Milan Pet Quality of Life instrument (MPQL). Overall, 235 participants reported about 242 adult pets (N_cats = 78, N_dogs = 164). Factor analysis confirmed the structure and internal reliability of the existing scales (RST-PQ, RST-Dog, RST-Cat, LAPS) and suggested a four-factor structure for the MPQL (physical, psychological, social, environmental). The results indicate that the pets’ psysical QoL was largely explained by pet-related elements (pets’ demographics and life experience, and pets’ personality). Conversely, the pets’ psychological QoL was explained mostly by owner-related elements, such as the owners’ demographics, COVID-19-related changes, and the owners’ personality. Predictably, the pets’ environmental QoL is mostly explained by environmental factors, such as the outdoor access in the home environment and the country. Finally, the pets’ social QoL was explained by the larger combination of models: pets’ characteristics and personality, environment and COVID-19-related changes, and the pet–human relationship. These findings can be explained by two non-mutually exclusive mechanisms. The reported changes may be a by-product of the COVID-19 pandemic’s psychological and lifestyle effects on the owners, which in turn alter the way the owners interact with their pets and look after them. However, the owners’ characteristics and mood may bias their answers regarding their pets.

Retinal Diseases of Senior Dogs

Aging consists of a physiological decline of an organism’s functional activity. During the aging process, the structural and functional changes of the retina can be observed. In most cases, progressive vision loss occurs due to the age related changes of the anterior segment. Retinal diseases, characteristic for senior dogs are: retinal detachment, hypertensive chorioretinopathy, sudden acquired retinal degeneration syndrome (SARDS), progressive retinal atrophy (PRA), glaucoma, retinopathy, cystoid degeneration and neoplasms. The examination of the retina in senior dogs is based on: ophthalmoscopic examination, electroretinography, spectral-domain optical coherence tomography (AD-OCT) and if necessary, histopathological examinations. Comprehensive knowledge regarding the senior dog’s health, significantly increases their quality of life.

Effect of senescence on morphological, functional and oxidative features of fresh and cryopreserved canine sperm

The present research aimed to compare the hormonal profile, sperm quality and freezability of young and senile dogs. Dogs were assigned into Young Group (n = 11) and Senile Group (n = 11), additionally divided into Fresh Semen Group and Cryopreserved Semen Group. Males were evaluated for libido score and blood estrogen and testosterone assay. Sperm morphofunctional evaluations were performed based on Computer Assisted Sperm Analysis, morphology, mitochondrial activity, mitochondrial membrane potential, plasma and acrosomal membrane integrity, and DNA fragmentation. Sperm oxidative features were: protein oxidation, lipid peroxidation and production of advanced glycation end-products. Young dogs had higher libido score, sperm velocity average pathway, linearity of motility and mitochondrial activity index and lower percentage of major defects, total defects and proximal cytoplasmic droplet, despite the lack of difference between hormone profile of aged dogs. Fresh semen of senile dogs had increased percentage of spermatozoa with high mitochondrial membrane potential compared to young dogs and to cryopreserved sperm. Cryopreserved semen of young dogs had higher acrosomal membrane integrity compared to the Senile Group. In conclusion, sperm of aged dogs have reduced quality, signaled by higher morphological defects, ultimately altering sperm mitochondrial function and sperm kinetics. Furthermore, spermatozoa from senile dogs are more sensible to cryoinjury.

The effect of age and sex on selected hematologic and serum biochemical analytes in 4,804 elite endurance-trained sled dogs participating in the Iditarod Trail Sled Dog Race pre-race examination program

Endurance-trained sled dogs provide a unique translational model to characterize changes in hematologic and serum biochemical analytes due to the aging process. The primary objective of this study was to determine the effect of age and sex on specific hematologic and serum biochemical parameters in the endurance trained sled dog. Longitudinal and cross-sectional data were analyzed from 9,746 blood and serum samples from 4,804 dogs collected over 7 years as part of the Iditarod Trail Sled Dog Race pre-race examination program. Mixed models analysis was used for statistical analysis and P < 0.01 was considered significant. Dogs ranged from 1–12 years of age and 39% were female. Serum total calcium and phosphorus concentrations and white blood cell count decreased nonlinearly to asymptotic values by 6.6, 3.1, and 6.9 years of age, respectively, equivalent to estimated physiologic ages in human years of 44, 27, and 46 years. Serum glucose concentrations reached their lowest value at 7.8 years of age, equivalent to an estimated human physiologic age of 50 years, after which time the concentration increased. Serum globulin concentrations increased with age, but nonlinearly for females and linearly for males. Most sex-related differences were <5%; however, females had lower serum urea nitrogen (14.7%) and creatinine (7.3%) concentrations, lower serum alanine aminotransferase activity (16.6%), and higher serum total bilirubin concentration (12.8%) and platelet count (6.0%). The endurance-trained sled dog provides an excellent model to separate the physiologic effects of age from those of a sedentary lifestyle on hematologic and serum biochemical analytes.

Effect of antioxidants, mitochondrial cofactors and omega-3 fatty acids on telomere length and kinematic joint mobility in young and old shepherd dogs - A randomized, blinded and placebo-controlled study

In dogs, decreasing telomere length is a biomarker for cellular aging. On a systemic level, aging affects the locomotor system in particular, leading to restricted joint mobility. As aging is thought to be related to oxidative stress, it may be counteracted by a diet enriched with antioxidants, mitochondrial cofactors and omega-3 fatty acids. This randomized, blinded and placebo-controlled study examined the influence of an accordingly enriched diet compared to a control diet on 36 young and 38 old shepherd dogs. At the outset, after 3 and after 6 months, mean and minimum telomere lengths were measured. Furthermore, minimum and maximum joint angles and range of motion of the shoulder, elbow, carpal, hip, stifle and tarsal joints were measured by computer-assisted gait analysis. A positive influence of the enriched diet on old dogs could be verified for minimum telomere length and all three parameters of the shoulder joint on the side with the higher vertical ground reaction force after 6 months. In the other joints there were less significant differences; in some cases they indicated a contrary influence of the enriched diet on young dogs, probably due to its reduced protein content. The greater effect of the enriched diet on minimum than on mean telomere length may be due to the higher preference of telomerase for short telomeres. The greater effect on shoulder joint mobility is explained by the greater influence of musculature and connective tissue in this joint. For elderly dogs it is advisable to feed these nutritional supplements.

Paving the Path Toward Retirement for Assistance Animals: Transitioning Lives

Assistance animals play significant roles in human therapy and well-being and represent a rapidly growing demographic of animals in society. Most research in the field of assistance animals has been focused on the effect of these animals on people. Only recently has there been a growing interest in the welfare and well-being of these animals and the effect of the work on the animals themselves. The concept of retirement, or withdrawing the animal from its working life, is an important welfare consideration that has received minimal discussion in the scientific literature. The notion of retirement is typically regarded as a reward earned after a lifetime of work, but this inevitable phase of an animal's working life has positive and negative implications for both animal and handler. Some of these implications include recognizing the emotional impact of this life-altering event on both animal and handler. The decisions of when and how to appropriately retire an animal are typically made at the discretion of the assistance animal agencies and handlers, but standard evidence-based guidelines for the proper retirement of assistance animals are currently unavailable. This review will provide considerations and recommendations for the retirement that assistance animals deserve.

Age-related changes in interstitial fibrosis and germ cell degeneration of the canine testis

Fifty-five healthy medium-sized dogs were divided into four groups; young (1-3 years old, n = 14), adult (>3 to 6 years old, n = 12), old (>6 to 9 years old, n = 14) and senile (>9 years old, n = 15). After routine orchiectomy, testes were collected, and the degree of white streak areas on cut surfaces was subjectively assessed. Later, testicular tissue sections were stained with haematoxylin and eosin and Masson's trichrome for evaluation of germ cell degeneration and the proportion of interstitial connective tissue, respectively. Semiquantitative severity scoring of germ cell degeneration and quantitative analysis of spermatogenic cells for spermatic index (SI) and Sertoli cell index (SEI) was performed. The score of white streak on cut surface area of the testes increased with age, being higher (p < 0.05) in senile dogs than other age groups; no difference was found between adult and old dogs. The proportion of testicular interstitial fibrosis was highest (p < 0.05) in senile dogs. Positive correlations between age and white streak area (rho = 0.77, p < 0.01) as well as age and interstitial fibrosis (rho = 0.63, p < 0.01) were observed. The severity of germ cell degeneration gradually increased with age and differed among age groups (p < 0.05). Age positively correlated with atrophy of seminiferous tubules (rho = 0.93, p < 0.01). The SI was lower (p < 0.05) in senile dogs compared to other age groups, and SI was not different among young, adult and old dogs. Conversely, SEI was significantly higher in senile dogs compared to young, adult and old dogs. A negative correlation between age and SI (rho = -0.69) and a positive correlation between age and SEI (rho = 0.68) were significant (p < 0.01). In conclusion, influence of age on testicular interstitial fibrosis and germ cell degeneration/depletion were pronounced in dogs over 9 years old.

Demographic Change Across the Lifespan of Pet Dogs and Their Impact on Health Status

Although dogs' life expectancies are six to twelve times shorter than that of humans, the demographics (e. g., living conditions) of dogs can still change considerably with aging, similarly to humans. Despite the fact that the dog is a particularly good model for human healthspan, and the number of aged dogs in the population is growing in parallel with aged humans, there has been few previous attempts to describe demographic changes statistically. We utilized an on-line questionnaire to examine the link between the age and health of the dog, and owner and dog demographics in a cross-sectional Hungarian sample. Results from univariate analyses revealed that 20 of the 27 demographic variables measured differed significantly between six dog age groups. Our results revealed that pure breed dogs suffered from health problems at a younger age, and may die at an earlier age than mixed breeds. The oldest dog group (>12 years) consisted of fewer pure breeds than mixed breeds and the mixed breeds sample was on average older than the pure breed sample. Old dogs were classified more frequently as unhealthy, less often had a “normal” body condition score, and more often received medication and supplements. They were also more often male, neutered, suffered health problems (such as sensory, joint, and/or tooth problems), received less activity/interaction/training with the owner, and were more likely to have experienced one or more traumatic events. Surprisingly, the youngest age group contained more pure breeds, were more often fed raw meat, and had owners aged under 29 years, reflecting new trends among younger owners. The high prevalence of dogs that had experienced one or more traumatic events in their lifetime (over 40% of the sample), indicates that welfare and health could be improved by informing owners of the greatest risk factors of trauma, and providing interventions to reduce their impact. Experiencing multiple life events such as spending time in a shelter, changing owners, traumatic injury/prolonged disease/surgery, getting lost, and changes in family structure increased the likelihood that owners reported that their dogs currently show behavioral signs that they attribute to the previous trauma.

Comparative kinematic gait analysis in young and old Beagle dogs

Age-related involution in dogs involves loss of muscle mass and changes in connective tissue and articular cartilage. The aim of this study was to examine whether an age-related influence on joint mobility can be detected in the absence of disease. Five young (mean age 2.0 years) and five old (mean age 10.4 years) healthy and sound Beagle dogs underwent computer-assisted gait analysis during locomotion on a treadmill. Shoulder, elbow, carpal, hip, stifle, and tarsal joint angles including joint angle progression curves, minimum and maximum joint angles, and range of motion (ROM) in degrees were analyzed. The old group had a smaller maximum joint angle (p = 0.037) and ROM (p = 0.037) of the carpal joint; there were similar tendencies in the shoulder, elbow, and carpal joints. Descriptive analysis of the progression curves revealed less flexion and extension of the forelimb joints. The results indicate restricted joint mobility of the forelimb in old dogs, primarily of the carpal joint. Results in the joints of the hindlimb were inconsistent, and the contrasting alterations may be due to a compensatory mechanism. As most alterations were found in the distal joints, these should receive particular attention when examining elderly dogs.

Utilising dog-computer interactions to provide mental stimulation in dogs especially during ageing

Aged dogs suffer from reduced mobility and activity levels, which can affect their daily lives. It is quite typical for owners of older dogs to reduce all activities such as walking, playing and training, since their dog may appear to no longer need them. Previous studies have shown that ageing can be slowed by mental and physical stimulation, and thus stopping these activities might actually lead to faster ageing in dogs, which can result in a reduction in the quality of life of the animal, and may even decrease the strength of the dog-owner bond. In this paper, we describe in detail a touchscreen apparatus, software and training method that we have used to facilitate dog computer interaction (DCI). We propose that DCI has the potential to improve the welfare of older dogs in particular through cognitive enrichment. We provide hypotheses for future studies to examine the possible effects of touchscreen use on physiological, behavioural and cognitive measures of dogs' positive affect and well-being, and any impact on the dog-owner bond. In the future, collaborations between researchers in animal-computer interaction, dog trainers, and cognitive scientists are essential to develop the hardware and software necessary to realise the full potential of this training and enrichment tool.

Computed tomography: a beneficial diagnostic tool for the evaluation of the canine prostate?

BACKGROUND

Prostatic diseases in intact male dogs are common. However, studies about the computed tomographic (CT) examination of the prostate in dogs are rare. The aim of the present study was to evaluate age related-changes in the canine prostate with the help of the CT and to evaluate whether measuring Hounsfield Units (HUs) in different morphological conditions of the prostate is of diagnostic value. Fifty pre- and post-contrast CT scans of the prostate of dogs were evaluated and divided into three groups according to the tissue structure: Group1 dogs with homogenous prostate tissue (16/50); group 2 with prostate cysts (26/50) and group 3 with inhomogeneous prostate tissue (8/50). The prostatic dimensions were measured and the ratio between length, height and width and the sixth lumbar vertebra was calculated. Median values of prostatic attenuation measured in HUs, using regions of interests (ROIs) were determined on pre- and post- contrast scans over the whole length of the prostate. The results were compared to the dog's age. Furthermore, the CT Images were compared with the results of ultrasonography (47/50).

RESULTS

On pre-contrast scans HUs within ROIs placed in the prostate did not differ statistically significantly between the different morphological groups (1: 37.7; 2: 36.3; 3: 39.8 HU). HUs within on the post- contrast scans showed statistically significant differences between the groups. Group one had a mean density of 93.6 HU, group two had a mean density of 106.1 HU and group three had one of 138.2 HU. The prostatic size in the first group was smaller than in the other groups, whereas the largest prostates were found in the second group. In six cases the post-contrast CT scan showed results that differed from the ultrasound examination. Dogs had a homogenous tissue in ultrasonography while the CT scan revealed an inhomogeneous tissue structure.

CONCLUSIONS

The CT examination can be a beneficial diagnostic tool for examining the prostatic size and for evaluating the prostatic tissue. The different HUs reflected age-related changes and alterations in the prostate while measuring the density of the prostate. Contrast agent application enables a more specific analysis of the prostate to be carried out and for precise changes in tissue structure to be observed.

Results of Screening of Apparently Healthy Senior and Geriatric Dogs

Background

There is a growing interest in health care of elderly dogs; however, scientific information about physical and laboratory examination findings in this age group is limited.

Objectives

To describe systolic blood pressure (SBP), and results of physical examination and laboratory tests in senior and geriatric dogs that were judged by the owner to be healthy.

Animals

Hundred client‐owned dogs.

Methods

Dogs were prospectively recruited. Owners completed a questionnaire. SBP measurement, physical, orthopedic and neurologic examination, direct fundoscopy and Schirmer tear test were performed. Complete blood count, serum biochemistry, and urinalysis were evaluated.

Results

Forty‐one senior and 59 geriatric dogs were included. Mean SBP was 170 ± 38 mmHg, and 53 dogs had SBP > 160 mmHg. Thirty‐nine animals were overweight. A heart murmur was detected in 22, severe calculus in 21 and 1 or more (sub)cutaneous masses in 56 dogs. Thirty‐two dogs had increased serum creatinine, 29 hypophosphatemia, 27 increased ALP, 25 increased ALT, and 23 leukopenia. Crystalluria, mostly amorphous crystals, was commonly detected (62/96). Overt proteinuria and borderline proteinuria were detected in 13 and 18 of 97 dogs, respectively. Four dogs had a positive urine bacterial culture. Frequency of orthopedic problems, frequency of (sub)cutaneous masses, and platelet count were significantly higher in geriatric compared with senior dogs. Body temperature, hematocrit, serum albumin, and serum total thyroxine concentration were significantly lower in geriatric compared with senior dogs.

Conclusions and Clinical Importance

Physical and laboratory abnormalities are common in apparently healthy elderly dogs. Veterinarians play a key role in implementing health screening and improving health care for elderly pets.

Exceptional longevity and potential determinants of successful ageing in a cohort of 39 Labrador retrievers: results of a prospective longitudinal study

BACKGROUND

The aim of this study was to describe the longevity and causes of mortality in 39 (12 males, 27 females) pedigree adult neutered Labrador retrievers with a median age of 6.5 years at the start of the study and kept under similar housing and management conditions. Body condition score was maintained between two and four on a 5-point scale by varying food allowances quarterly. The impact of change in body weight (BW) and body composition on longevity was analysed using linear mixed models with random slopes and intercepts.

RESULTS

On 31 July 2014, 10 years after study start, dogs were classified into three lifespan groups: 13 (33 %) Expected (≥9 to ≤12.9 years), 15 (39 %) Long (≥13 to ≤15.5 years) and 11 (28 %) Exceptional (≥15.6 years) with five still alive. Gender and age at neutering were not associated with longevity (P ≥ 0.06). BW increased similarly for all lifespan groups up to age 9, thereafter, from 9 to 13 years, Exceptional dogs gained and Long-lifespan dogs lost weight (P = 0.007). Dual-energy x-ray absorptiometer scans revealed that absolute fat mass increase was slower to age 13 for Long compared with Expected lifespan dogs (P = 0.003) whilst all groups lost a similar amount of absolute lean mass (P > 0.05). Percent fat increase and percent lean loss were slower, whilst the change in fat:lean was smaller, in both the Exceptional and Long lifespan compared with Expected dogs to age 13 (P ≤ 0.02). Total bone mineral density was significantly lower for Expected compared to Exceptional and Long lifespan dogs (P < 0.04).

CONCLUSIONS

This study shows that life-long maintenance of lean body mass and attenuated accumulation of body fat were key factors in achieving a longer lifespan. The results suggest that a combination of a high quality plane of nutrition with appropriate husbandry and healthcare are important in obtaining a greater than expected proportion of Labrador retrievers living well beyond that of the expected breed lifespan: 89.7 % (95 % CI 74.8-96.7 %) dogs were alive at 12 years of age and 28.2 % (95 % CI 15.6-45.1 %) reaching an exceptional lifespan of ≥15.6 years.