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Aging is a complex, multifactorial process, where different life stages reflect changes in metabolic processes, immune capacities, and genetic/epigenetic repertoires. With accumulating exposure to environmental stresses and deterioration of physiological functions, body systems become more prone to low-grade chronic inflammation and an increasing range of pathologies. We hypothesized that differential susceptibility to diseases across life span reflects phased changes in an organism’s physiological capacity that may highlight when interventions may be appropriately used. Furthermore, the number of life stages may vary between species and be impacted by signalment such as breed. We tested this hypothesis using disease diagnoses data from veterinary electronic medical records containing almost 2 million cats and over 4 million dogs. Bi-clustering (on rates of disease diagnoses) and adaptive branch pruning were used to identify age clusters that could be used to define adult life stages. Clustering among diagnoses were then interpreted within the context of each defined life stage. The analyses identified 5 age clusters in cats and 4 age clusters within each of the 4 canine breed size categories used. This study, using population scale data for two species, one with differential size and life expectancies, is the first to our knowledge to use disease diagnosis data to define adult life stages. The life stages presented here are a result of a data-driven approach to age and disease stratification and are intended to support conversations between clinicians and clients about appropriate health care recommendations.

Early responses in healthy adult dogs fed grain-free diets with high inclusion of split peas (20%) and lentils (40%) that may lead to canine diet-induced dilated cardiomyopathy (DCM) were investigated. To help understand the clinical relevance of the findings, a survey of electronic health records (EHR) was conducted of dogs with and without suspected DCM for comparison. Control and Test diets were fed to Labrador retriever dogs for 30 days (n = 5 and 6, respectively). Blood and urine samples collected at baseline and days 3, 14 and 28/30 were analyzed for hematology, clinical biochemistry and taurine concentrations. The EHRs of dogs at Banfield® Pet Hospitals in the 2-year period 2018-2019 were surveyed, revealing 420 dogs diagnosed with DCM, which were compared with 420 breed, gender and age-matched healthy control dogs. Compared to baseline values, feeding the Test diet for 28 days caused progressive, significant (p

In dogs, optimal growth is critical for future health and wellbeing. Recently, a series of evidence-based growth standards, based on bodyweight, were developed for male and female dogs across 5 different size categories. The aim of the current study was to compare growth curves depicted by the standards with patterns of growth in dogs that were either healthy, had abnormal body condition, or had various diseases with the potential to affect growth. The data came from 2 research colonies in Europe (France and UK), and a large corporate network of primary care veterinary hospitals across the USA. Age and bodyweight data were used to model growth in healthy dogs, in dogs that became overweight or underweight by 3 years of age, and in dogs with diseases associated with altered growth. Centile line crossing during the growth phase was uncommon in healthy dogs, with 2 centile lines. In contrast, centile line crossing was more frequent in dogs with abnormal growth patterns or abnormal body condition. Dogs that developed obesity by 3 years grew faster than the growth standards predicted, and 68% crossed ≥2 centile lines in an upwards direction. Dogs with conditions associated with accelerated growth also grew faster than expected, and 54% crossed ≥2 centile lines. In contrast dogs that became underweight by 3 years gained weight slower than expected, and 49% crossed ≥2 centile lines in a downwards direction. These results suggest that the growth standards are useful for monitoring healthy growth in dogs. Prospective studies are now required to confirm these findings and to determine whether early intervention can prevent the development of diseases.

Background There is an association between overweight status and life span in kenneled dogs, but a similar association has not been reported for pet dogs. Objectives To examine the effects of being overweight in middle age on the life span of neutered client-owned dogs. Animals Fifty-thousand seven-hundred eighty seven middle-aged neutered client-owned dogs attending a network of approximately 900 veterinary hospitals across North America. Methods Retrospective case-control study. For each of 12 breeds, groups of dogs aged between 6.5 and 8.5 years were identified as being in "overweight" or "normal" body condition. Within each breed and sex, differences in life span between dogs in normal body condition and overweight body condition in the 2 groups were then analyzed by Cox proportional hazards models. Results For all breeds, instantaneous risk of death for dogs in overweight body condition was greater than those in normal body condition throughout the age range studied, with hazard ratios ranging from 1.35 (99.79% confidence interval [CI] 1.05-1.73) for German Shepherd dog to 2.86 (99.79% CI 2.14-3.83) for Yorkshire Terrier. In all breeds, median life span was shorter in overweight compared with normal weight dogs, with the difference being greatest in Yorkshire Terriers (overweight: 13.7 years, 99.79% CI 13.3-14.2; normal: 16.2 years, 99.79% CI 15.7-16.5) and least in German Shepherd dogs (overweight: 12.1 years, 99.79% CI 11.8-12.4; normal: 12.5 years, 99.79% CI 12.2-12.9). Conclusions and clinical importance Veterinary professionals should consider promoting healthy body condition for dogs, particularly from midlife onward.

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.

To understand the effects of neutering on food intake, body weight (BW) and body composition in kittens, data from an unrelated study were subjected topost hocanalysis. A total of twelve pairs of 11-week-old female littermates were randomly assigned to either a neutered group (neutered at 19 weeks old) or an entire group (kept entire) and offered free access to a dry diet until the age of 1 year. Neutered kittens exhibited increased food intake and increased BW after neutering (bothP P = 0·00 014). The intake was then reduced until there was no significant difference between the groups 18 weeks post-neutering. By 52 weeks of age, the neutered kittens were 24 (95 % CI 11, 39) % heavier than entire littermates (P P = 0·0028). Neutered kittens continued to grow significantly fatter after neutering (allP ad libitum.Moreover, to maintain an ideal BCS, entire kittens consumed 93 (95 % CI 87, 100) % of their theoretical intake at 26 weeks of age, and 79 (95 % CI 72, 87) % at 52 weeks of age, suggesting that the current energy recommendation is inappropriate for these kittens.

Breed, sex and age effects on haematological and biochemical variables were investigated in 24 labrador retriever and 25 miniature schnauzer dogs during the first year of life. Blood samples were taken regularly between weeks 8 and 52. White blood cell and red blood cell counts, haemoglobin concentration, haematocrit, mean cell volume, mean cell haemoglobin, mean cell haemoglobin concentration, platelet count as well as total protein, albumin, calcium, phosphate, alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, glutamate dehydrogenase, total cholesterol, triglycerides, creatine and urea were evaluated. For all haematological and biochemical parameters, there were significant effects of age on test results. Statistically significant effects for breed and the breed×age interaction on test results were observed for most of the parameters with the exception of haemoglobin. Variations in test results illustrate growth related alterations in body tissue and metabolism leading to dynamic and marked changes in haematological and biochemical parameters, which have to be considered for the interpretation of clinical data obtained from dogs in the first year of life.

Research in rodents has shown that dietary vitamin A reduces body fat by enhancing fat mobilisation and energy utilisation; however, their effects in growing dogs remain unclear. In the present study, we evaluated the development of body weight and body composition and compared observed energy intake with predicted energy intake in forty-nine puppies from two breeds (twenty-four Labrador Retriever (LAB) and twenty-five Miniature Schnauzer (MS)). A total of four different diets with increasing vitamin A content between 5.24 and 104.80 mu mol retinol (5000-100 000 IU vitamin A)/4184 kJ (1000 kcal) metabolisable energy were fed from the age of 8 weeks up to 52 (MS) and 78 weeks (LAB). The daily energy intake was recorded throughout the experimental period. The body condition score was evaluated weekly using a seven-category system, and food allowances were adjusted to maintain optimal body condition. Body composition was assessed at the age of 26 and 52 weeks for both breeds and at the age of 78 weeks for the LAB breed only using dual-energy X-ray absorptiometry. The growth curves of the dogs followed a breed-specific pattern. However, data on energy intake showed considerable variability between the two breeds as well as when compared with predicted energy intake. In conclusion, the data show that energy intakes of puppies particularly during early growth are highly variable; however, the growth pattern and body composition of the LAB and MS breeds are not affected by the intake of vitamin A at levels up to 104.80 mu mol retinol (100 000 IU vitamin A)/4184 kJ (1000 kcal)., Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe, 603

The safe upper limit for inclusion of vitamin A in complete diets for growing dogs is uncertain, with the result that current recommendations range from 5.24 to 104.80 mu mol retinol (5000 to 100 000 IU vitamin A)/4184 kJ (1000 kcal) metabolisable energy (ME). The aim of the present study was to determine the effect of feeding four concentrations of vitamin A to puppies from weaning until 1 year of age. A total of forty-nine puppies, of two breeds, Labrador Retriever and Miniature Schnauzer, were randomly assigned to one of four treatment groups. Following weaning at 8 weeks of age, puppies were fed a complete food supplemented with retinyl acetate diluted in vegetable oil and fed at 1ml oil/100 g diet to achieve an intake of 5.24, 13.10, 78.60 and 104.80 mu mol retinol (5000, 12 500, 75 000 and 100 000 IU vitamin A)/4184 kJ (1000 kcal) ME. Fasted blood and urine samples were collected at 8, 10, 12, 14, 16, 20, 26, 36 and 52 weeks of age and analysed for markers of vitamin A metabolism and markers of safety including haematological and biochemical variables, bone-specific alkaline phosphatase, cross-linked carboxyterminal telopeptides of type I collagen and dual-energy X-ray absorptiometry. Clinical examinations were conducted every 4 weeks. Data were analysed by means of a mixed model analysis with Bonferroni corrections for multiple endpoints. There was no effect of vitamin A concentration on any of the parameters, with the exception of total serum retinyl esters, and no effect of dose on the number, type and duration of adverse events. We therefore propose that 104.80 mu mol retinol (100 000 IU vitamin A)/4184 kJ (1000 kcal) is a suitable safe upper limit for use in the formulation of diets designed for puppy growth., Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe, 686

Objective—To determine the effects of increases in dietary intake of polyunsaturated and saturated fatty acids on plasma lipid and lipoprotein concentrations and activity of associated enzymes in healthy domestic cats. Animals—16 healthy adult sexually intact female cats. Procedures—A baseline diet (40% energy from fat) and 4 test diets, with increased amounts of fat (51% and 66% energy from fat) from the addition of polyunsaturated and saturated fatty acids, were fed for 6 weeks each. Plasma cholesterol, triglyceride, and lipoprotein cholesterol concentrations, along with activities of lipoprotein lipase, hepatic lipase, and lecithin-cholesterol acyl transferase, were measured at the end of each feeding period. Results—Diet, amount of fat, or ratio of polyunsaturated to saturated fatty acids had no effect on plasma concentrations of cholesterol, triglycerides, and very–low-density or high-density lipoproteins or the activity of lecithin-cholesterol acyl transferase. Low-density lipoprotein concentrations were significantly lower in cats fed a high-fat diet containing polyunsaturated fatty acids. Lipoprotein concentration and hepatic lipase activity were significantly higher in cats fed the fat-supplemented diets, and this was unrelated to whether diets were enriched with polyunsaturated or saturated fatty acids. Conclusions and Clinical Relevance—Diets containing up to 66% of energy from fat were tolerated well by healthy cats and did not affect plasma lipid concentrations. Therefore, high-fat diets probably will not contribute to hypercholesterolemia or hypertriglyceridemia incats.