How does evolutionary evaluation illuminate body size among canids?

In this review, we examine mammalian body size as it reflects life history and genomic composition, with a primary focus on canids and the domestication of the gray wolf. The range of variation in body size is greater among Carnivora than any other terrestrial order. In the Canidae, this range is some 2 orders of magnitude.

Developmental features of the canid proximocaudal femur.

We continued direct morphological studies of the canid coxofemoral joint, considering early-life spatial relationships around the locus of the proximocaudal joint capsule insertion. Our primary goal was to elucidate the postnatal developmental gross anatomy of the proximocaudal femur, among juveniles across Canidae. From an original database of 267 independent (museum) specimens from 11 canid taxa and 1 hybrid taxon, we identified 29 ancient or modern candidate juvenile specimens (nine taxa and one hybrid taxon).

Morphology-based diagnostics of "protodogs." A commentary to Galeta et al., 2021, Anatomical Record, 304, 42-62, doi: 10.1002/ar.24500.

In a recent article in this journal, Galeta et al., (2020) discussed eight Pleistocene "protodogs" and seven Pleistocene wolves. Those "protodogs" had been diagnosed in earlier publications, based on skull morphology.

Osteoarthritis from evolutionary and mechanistic perspectives.

Developmental osteogenesis and the pathologies associated with tissues that normally are mineralized are active areas of research. All of the basic cell types of skeletal tissue evolved in early aquatic vertebrates. Their characteristics, transcription factors, and signaling pathways have been conserved, even as they adapted to the challenge imposed by gravity in the transition to terrestrial existence.

A Long-Term Lens: Cumulative Impacts of Free-Roaming Cat Management Strategy and Intensity on Preventable Cat Mortalities.

This study used a previously developed stochastic simulation model (1) to estimate the impact of different management actions on free-roaming kitten and cat mortality over a 10-year period. These longer-term cumulative impacts have not been systematically examined to date. We examined seven management scenarios, including: (1) taking no action, (2) low-intensity removal, (3) high-intensity removal, (4) low-intensity episodic culling, (5) high-intensity episodic culling, (6) low-intensity trap-neuter-return (TNR), and (7) high-intensity TNR.

Suspected hypertrophic osteopathy in an ancient canid: Differential diagnosis of possible etiologies.

Hypertrophic osteopathy (HO) has been reported in numerous mammalian species, but no reports address the range of conditions that can lead to HO, or the implications of those conditions, for archaeological diagnosis. We describe suspected HO from skeletal remains of an ancient large domestic dog recovered in Iowa, USA, at the Cherokee Sewer site. Canid remains from this site date 7430-7020calBP.

Simulating free-roaming cat population management options in open demographic environments.

Large populations of free-roaming cats (FRCs) generate ongoing concerns for welfare of both individual animals and populations, for human public health, for viability of native wildlife populations, and for local ecological damage. Managing FRC populations is a complex task, without universal agreement on best practices. Previous analyses that use simulation modeling tools to evaluate alternative management methods have focused on relative efficacy of removal (or trap-return, TR), typically involving euthanasia, and sterilization (or trap-neuter-return, TNR) in demographically isolated populations.

Lessons from a non-domestic canid: joint disease in captive raccoon dogs (Nyctereutes procyonoides).

The purpose of this study was to describe pathological changes of the shoulder, elbow, hip and stifle joints of 16 museum skeletons of the raccoon dog (Nyctereutes procyonoides). The subjects had been held in long-term captivity and were probably used for fur farming or research, thus allowing sufficient longevity for joint disease to become recognisable. The prevalence of disorders that include osteochondrosis, osteoarthritis and changes compatible with hip dysplasia, was surprisingly high.

Chronology of hip dysplasia development in a cohort of 48 Labrador retrievers followed for life.

Objective: To determine the chronology of radiographic signs of canine hip dysplasia (CHD), specifically joint laxity and secondary osteoarthritis (OA).

Study Design: Longitudinal cohort study.

Animals: Paired littermates, 48 Labrador retrievers.

The changing understanding of ageing. Part 3: Diseases of ageing.

This third and final paper in this series considers ageing mechanisms across species, with emphasis on conserved metabolic pathways that relate to disease. The growth hormone (GH)-insulin-like growth factor (IGF-1)-insulin axis continues as an example of how critical pathways might relate to longevity and senescence. Aligning theory, research outcomes and clinical investigations at the levels of the cell, organism and population, is suggested as a means by which to consider the many complexities of the ageing process in an orderly fashion.

The changing understanding of ageing. Part 2: Body composition, metabolism and cell death.

This second of three discussions about ageing biology and diseases continues at the level of the organism, examining the relationship among body composition, late life and diseases. One view of significant age-related mass loss in humans suggests that anabolic failure is associated with various precipitating factors that may share anorexia in common. Lean mass decline with even partial anorexia should alert clinicians to monitor patients for emergence of otherwise subclinical disease.

The changing understanding of ageing. Part 1: Evaluating ageing theories and studies.

This is the first of three discussions on emerging views of ageing, its derivation, and ageing-related diseases. To offer a context for the series, this first report briefly reviews several major early and recent theoretical debates. Arguments for and against several well-known ageing theories are presented for their veterinary relevance, including mutation, pleiotropy, reproduction-longevity trade-offs, oxygen metabolism and ageing as a genomically programmed product of natural selection.

Age relationships of postmortem observations in Portuguese Water Dogs.

A dog model has been used to evaluate histological changes arising from senescence. Autopsies of 145 Portuguese Water Dogs have been used to evaluate the individual and group "state of health" at time of death. For each dog, weights or dimensions of organs or tissues were obtained, together with histological evaluation of tissues.

Un-united medial epicondyle of the humerus: radiographic prevalence and association with elbow osteoarthritis in a cohort of labrador retrievers.

Objective: To longitudinally characterize the radiographic appearance of un-united medial epicondyle (UME) of the humerus, evaluate UME association with osteoarthritis (OA) and consider its relevance to the elbow dysplasia complex.

Study Design: Longitudinal cohort study.

Animals: Labrador retrievers (n=48) from 7 litters.

Exploring human/animal intersections: converging lines of evidence in comparative models of aging.

At a symposium convened on March 8, 2007 by the Institute on Aging at the University of Pennsylvania, researchers from the University's Schools of Medicine and Veterinary Medicine explored the convergence of aging research emerging from the two schools. Studies in human patients, animal models, and companion animals have revealed different but complementary aspects of the aging process, ranging from fundamental biologic aspects of aging to the treatment of age-related diseases, both experimentally and in clinical practice. Participants concluded that neither animal nor human research alone will provide answers to most questions about the aging process.

The effects of lifetime food restriction on the development of osteoarthritis in the canine shoulder.

Objective: To report effects of age and lifetime food restriction on development and progression of shoulder joint osteoarthritis (OA) in Labrador retriever dogs.

Study Design: Longitudinal life-span, cohort study.

Animals: Labrador retriever dogs (n=48).

Diet restriction and ageing in the dog: major observations over two decades.

This report reviews decade two of the lifetime diet restriction study of the dog. Labrador retrievers (n 48) were paired at age 6 weeks by sex and weight within each of seven litters, and assigned randomly within the pair to control-feeding (CF) or 25 % diet restriction (DR). Feeding began at age 8 weeks.

Evaluation of a circumferential femoral head osteophyte as an early indicator of osteoarthritis characteristic of canine hip dysplasia in dogs.

Objective: To determine the relationship between a circumferential femoral head osteophyte (CFHO) and osteoarthritis characteristic of canine hip dysplasia, and to ascertain whether CFHO, like osteoarthritis, varies between diet-restricted and control-fed dogs.

Design: Longitudinal cohort study.

Animals: 48 Labrador Retrievers.

A single IGF1 allele is a major determinant of small size in dogs.

The domestic dog exhibits greater diversity in body size than any other terrestrial vertebrate. We used a strategy that exploits the breed structure of dogs to investigate the genetic basis of size. First, through a genome-wide scan, we identified a major quantitative trait locus (QTL) on chromosome 15 influencing size variation within a single breed.

Heritable components of feline hematology, clinical chemistry, and acid-base profiles.

Four erythrocyte variables (erythrocyte count, hemoglobin, mean cell volume, packed cell volume), 14 serum variables (alanine transferase, albumin, alkaline phosphatase, calcium, chloride, cholesterol, creatinine, glucose, phosphorus, potassium, sodium, total protein, triglycerides, urea nitrogen), and 7 venous acid-base variables (base excess, bicarbonate, carbon dioxide partial pressure, oxygen partial pressure, oxygen saturation, pH, and total carbon dioxide) were evaluated for heritability in domestic cats (Felis catus). Values used for individual cats were expressed as the mean over all lifetime measurements, using 444-530 animals for clinical chemistry, 629 animals for acid-base, and 564 animals for erythrocyte metrics. Gender and age at death (where applicable) also were evaluated for correlation with variables.