Topic:Age Factors
Age factors in horses encompass a range of physiological and developmental changes that occur as horses mature from foals to adults and eventually into their senior years. These factors include variations in metabolic rate, immune function, and musculoskeletal development, which can influence a horse's health, performance, and nutritional needs. Age-related changes can also affect how horses respond to medications, recover from injuries, and maintain overall vitality. Researchers study these aspects to understand better how age impacts equine health and management. This page compiles peer-reviewed research studies and scholarly articles that explore the effects of age on equine physiology, health management, and disease susceptibility.
Biochemical markers of bone metabolism in draught and warmblood horses. Concentrations of the cross-linked carboxyterminal telopeptide of type I collagen (ICTP) and osteocalcin (OC) have been determined in the serum of one hundred clinically healthy adult Draught or Warmblood horses. The correlation between these two markers has been evaluated and the influence of gender, age and type of horse described. No significant variations were observed between animals of different sex, but a significant inverse correlation (P < 0.0001) with age was observed for both measured parameters. After correction for age, serum levels of OC were found to be lower in Draught [adjuste...
[Radiologic description of the growth plates of the atlas and axis in foals]. Fractures of the first two cervical vertebrae, atlas and axis, may occur in foals for different reasons, e.g. in cases of a fall, going head over heels or when being hit by a hoof. The tentative clinical diagnosis can be confirmed by x-raying the standing animal, with aid of computed tomography in the anaesthetized foal respectively. The growth plates however, and their time of closure have to be considered when interpreting radiographs. In the atlas there are two ventrolateral plates and one dorsomedian cartilagineous plate. Only the dorsal plate, however, can be found in the dorsoventral pro...
Flat, hurdle and steeple racing: risk factors for musculoskeletal injury. A retrospective case-control study was conducted to identify and quantify risk factors for serious musculoskeletal injury sustained at 4 Australian metropolitan racetracks. During the period of study (August 1988-July 1995) there were 196 cases from flat racing, 52 cases from hurdle racing and 53 cases from steeplechases. The incidences of fatal musculoskeletal injuries per start for flat, hurdle and steeple races were 0.06, 0.63 and 1.43% respectively. Logistic regression identified harder track surfaces, horses being older than age 3 years, one racecourse (Flemington) and jumping races as si...
Incidence and morphology of endometrial angiopathies in mares in relationship to age and parity. The morphology of endometrial blood vessels in uterine biopsy specimens from mares of varying age and reproductive status was examined by light (n = 117) and electron microscopy (n = 13), and additionally after elastase digestion (n = 86). Inflammatory vascular alterations were observed in 20.5% of the specimens. Smaller and larger arterial and venous vessels demonstrated mild to severe degenerative lesions. Unaltered vessels were detected only in maiden mares. Vessels in older maiden mares were frequently affected by angiosclerotic changes, characterized by mild to moderate perivascular and i...
Accuracy of different methods of estimating the weight of horses. Six hundred horses of different ages, heights and breeds were weighed on a weighbridge and had their weights estimated by two weigh tapes, 1 and 2, by a formula, and by a visual estimate. For the population as a whole, the most accurate method was the formula (mean [sd] 98.6 [10.6] per cent) closely followed by weigh tape 2 (98.1 [8.1] per cent). Tape 1 and the visual estimate were the least accurate (112.0 [9.3] and 88.3 [20.1] per cent respectively). When the population was divided into two height groups, the formula and weigh tape 2 were the most accurate for horses or = 15 hh weigh tape 1...
Prevalence and risk factors of bone spavin in Icelandic horses in Sweden: a radiographic field study. The present field study was performed to estimate the prevalence of radiographic signs of bone spavin (RSBS) and to evaluate some possible risk factors for RSBS in the Icelandic horse in Sweden. The survey included horses from 11 farms involving 379 horses, comprising 238 geldings, 125 mares and 16 stallions. Age ranged from 0 to 19 years with a mean age of 8.1 years. Horses were radiographed with a dorsolateral-plantaromedial-oblique projection of both tarsi. Information about age, gender, origin, working intensity, number of gaits and age when saddle broken were obtained by interviewing the ...
Hematologic and serum biochemical variables and plasma corticotropin concentration in healthy aged horses. To compare hematologic and serum biochemical variables and plasma ACTH concentration between healthy horses 5 to 12 years old and those more than 20 years old. Methods: 30 healthy horses 5 to 12 years old and 30 healthy horses more than 20 years old. Methods: Venous blood was collected from all horses, and CBC and serum biochemical analysis were performed for each horse. Plasma ACTH concentration was determined by radioimmunoassay. Student's paired t-test or the Mann-Whitney rank sum test was used to compare values between control and aged horse groups. Results: Compared with values for contro...
Morphometric analysis of endometrial periglandular fibrosis in mares. To develop an objective, quantifiable assay for endometrial periglandular fibrosis (EPF) and correlate assay results with histologic and ultrastructural changes in equine endometrial biopsy specimens. Methods: Endometrial biopsy specimens from 70 mares from 3 to 27 years old in estrus. Methods: In a double-blinded study design, endometrial biopsy specimens were graded histologically (modified Kenney classification) for EPF and inflammation. Endometrial periglandular collagen volume fraction (%EPCVF) was determined by light microscopic image analysis of picrosirius red-stained sections. Specime...
Reliability of using results of abdominal fluid analysis to determine treatment and predict lesion type and outcome for horses with colic: 218 cases (1991-1994). To assess clinical utility of abdominal fluid analysis in predicting outcome, lesion type, and whether medical or surgical treatment is indicated for horses with colic. Methods: Retrospective study. Methods: 218 horses > 1 year old. Methods: Horses were classified on the basis of age, site of lesion, lesion type (nonstrangulating vs strangulating), type of treatment (medical vs surgical), and outcome (survival vs nonsurvival). Sensitivity and specificity of using age and results of abdominal fluid analysis, individually and in combination, to predict lesion type, type of treatment, and outc...
The accuracy of the dorsoproximal-dorsodistal projection in assessing third carpal bone sclerosis in standardbred trotters. Thirty-five carpal joints from 20 standardbred trotters, age 1 to 7 years, all euthanized for nonorthopedic reasons, were examined to investigate the correlation between assessments of subchondral bone sclerosis in the third carpal bone from radiographs in the dorsoproximal-dorsodistal (DPr-DDi) projection and histomorphometric bone volume density measurements. The agreement between assessments of sclerosis from antemortem versus postmortem radiographs was also evaluated. Bones graded as sclerotic in the DPr-DDi projection had significantly higher bone volume density values for all areas of me...
Neopterin values in selected groups of normal animals. To establish baseline information on neopterin concentrations in livestock, companion and laboratory animals and identify the factors that may influence these concentrations, blood samples were taken from normal dairy cattle, horses, llamas, dogs, cats and rats of varying ages and sexes. In addition, neopterin concentrations in normal, adult equines were compared with those found in racing Thoroughbreds. There were no differences due to sex, sexual maturity, pregnancy, castration, or age. For all ages and sexes combined, mean neopterin concentrations were significantly lower in llamas (2.27+/-...
Gasterophilus intestinalis infections in horses in Belgium. Over a period of one year, from December 1995 to November 1996, larvae of Gasterophilus intestinalis were found in 193 horse stomachs (58%) of 330 that were examined in two Belgian slaughter houses. When August is excluded, 62% of the stomachs had bot larvae. No other Gasterophilus species were identified. The monthly prevalence ranged from 9% in August to 75% in November and December. The mean intensity of bot larvae varied from 8 in August to 29 in March, and the majority of the horses (67%) harboured less than 50 larvae. Prevalences and intensities were not affected by age, but mares were m...
Dental embryology, anatomy, development, and aging. Equine practitioners should be knowledgeable of dental anatomy and development to enhance their skill of age estimation of horses. The permanent teeth of horses are continually undergoing changes in shape and appearance. These changes may be used to suggest a reasonable age range for a horse.
Retinal degeneration associated with vitamin E deficiency in hunting dogs. A group of Walker Hounds and Beagles that were fed a diet of table scraps were examined because of slow, progressive loss of vision. Clinical and microscopic features of the disease were correlated to the dogs' micronutrient status. Sensory retinal degeneration, predominantly in the central tapetal fundus, was found in all dogs, and severity of changes varied with age of the dog. Plasma, serum, and tissue concentrations of vitamin E were low in affected dogs (10 to 40% of control values). Lipofuscin accumulation was found on microscopic examination in retinal pigment epithelium, smooth muscle ...
Modifications of the form and amplitude of the electrocardiographic QRS complex during growth in the Spanish-bred Horse. Configuration and amplitude values of the QRS complex of the electrocardiogram were studied with standard Einthoven leads in 173 healthy Spanish-bred (Andalusian) horses, aged between 1 month and 17 years. Animals which were 1 month old had a predominantly negative QRS complex, whereas a predominantly positive complex direction was found in the rest of the animals. Statistically significant variations were found for the Q-wave and QRS main vector between the different age groups, with highest values for the Q-wave and most negative values for the direction of the QRS main vector in animals up ...
Mechanical correlations derived from segmental histologic study of the equine superficial digital flexor tendon, from foal to adult. To assess histologic variations of the equine superficial digital flexor tendon (SDFT) according to site and to horse age and activity, and to correlate these data with reported segmental mechanical results. Methods: Superficial digital flexor tendons isolated from 42 horses 0.5 hour to 23 years old. Methods: 7 segments of each SDFT were delimited and submitted for conventional histologic examination. Each segment was examined and graded for fiber undulation, cellularity, number and size of interfascicular connective spaces (ICS), presence or absence of focal and diffuse chondroid metaplasia, ...
Glomerular filtration rate, effective renal plasma flow, blood pressure and pulse rate in the equine neonate during the first 10 days post partum. The aim of this study was to determine glomerular filtration rate (GFR), effective renal plasma flow (RPF) and filtration fraction (FF) values in Pony foals during the first 10 days post partum in order to assess any age-related changes and the reliability of the single injection inulin/p-aminohippurate (PAH) method. Arterial blood pressure and pulse rate were determined in Pony and Thoroughbred (TB) foals during the first 10 days post partum to establish age-related changes, differences between breeds and possible interrelationships with GFR and RPF. Inulin and PAH were injected intravenously...
Ageing Arab horses by their dentition. The dentition of 170 Arab horses of known ages was examined and compared with the dental characteristics of trotter horses and Belgian draft horses of the same ages. The results indicated that inaccuracies in the determination of the age of horses by their dentition may result, at least partly, from differences between the breeds of horse involved because there were some major differences between the three breeds examined. These differences increased as the horses' true age increased. In general, the rate of dental wear was slower in the Arab horses than in trotter horses and Belgian draft hor...
Seroprevalence of Babesia equi among horses in Israel using competitive inhibition ELISA and IFA assays. Sera from 361 horses were tested by indirect immunofluorescence antibody test (IFA) and by competitive inhibition ELISA (cELISA), to detect antibodies to Babesia equi. The concordance between the assays was 95.7%. Application of a cutoff based on a calculated percent inhibition of 20% inhibition was used. Approximately one-third of all the horses tested were found serologically positive to B. equi, with more horses testing positive from northern Israel. Among horses raised with access to pasture there was a significant difference in the percentage of seropositive reactors (76.6% in the north ...
Plasma aspartate aminotransferase and creatine kinase activities in thoroughbred racehorses in relation to age, sex, exercise and training. In order to investigate the effect of age, sex and month on the response of plasma aspartate aminotransferase (AST) and creatine kinase (CK) to exercise, blood samples were collected once a month between March and September from a group of 40 2- and 3-year-old (2yo and 3yo) thoroughbred racehorses (kept under the same managemental regimen) at rest before exercise (PRE) and at 2 (2H) and 24 h (24H) post-exercise. The absolute change in activities between the 2H and PRE samples (2H delta) and the 24H and PRE samples (24H delta) was also calculated. Age had a significant effect on all measured an...
Relationship between plasma testosterone concentrations and age, breeding season and harem size in Misaki feral horses. Jugular vein blood samples were collected from 23 young and sexual mature feral stallions to examine the relationship between plasma testosterone concentration and age, breeding season or harem size. Testosterone concentration increased with the age of the stallions until they formed their own harems, at about 4 to 6 years old. Seasonal variations in testosterone concentrations were observed, and found to be significantly higher (P<0.001) throughout the breeding season than non-breeding season, from 3 years of age. Testosterone levels were correlated with harem size for individual stallions...
Association between long periods without high-speed workouts and risk of complete humeral or pelvic fracture in thoroughbred racehorses: 54 cases (1991-1994). To determine whether a two-month or longer period without official high-speed workouts (lay-up) is associated with humeral or pelvic fracture in Thoroughbred racehorses. Methods: Reprospective study. Methods: Thoroughbred racehorses in California that were euthanatized because of a complete humeral or pelvic fracture. Methods: Age, sex, activity, number of lay-ups, number of days from a race or official timed workout to fracture, number of days from end of last lay-up to fracture, mean duration of lay-ups, and total number of days in race training were compared between horses with humeral frac...
Peculiarities of vitamin D and of the calcium and phosphate homeostatic system in horses. The aim of the present study was to investigate the importance of putative regulatory factors of the calcium (Ca) and inorganic phosphate (P(i)) homeostatic system in the horse. The concentrations of Ca, P(i), vitamin D metabolites, parathyroid hormone (PTH), the activity of the alkaline phosphatase (AP) and the concentration and binding properties of vitamin D binding protein (DBP) were measured in the plasma. In addition, the ability of the renal cortex to hydroxylate calcidiol into 24,25(OH)2D3 and 1,25(OH)2D3 was evaluated in vitro. The plasma concentration of Ca (3.2 +/- 0.15 mmol.L-1, N ...
Living fibroblast cells in the oviductal masses of mares. The object of this experiment was to estimate the number and type of living cells in oviductal masses of mares. Oviducts of abattoir mares were dissected, divided into 3 sections, and flushed individually. Oviductal masses were recovered from 220 of 250 mares and from 389 of 500 oviducts. A greater number of masses was recovered from the left than the right oviducts. A higher percentage of masses was recovered from the ampullary-isthmic junction than from the ampulla or isthmus. The number of masses increased slightly with increasing mare age and was weakly correlated with the number of unfert...
[Activities of the enzymes LDH, gamma-GT, GOT, GPT and lactoperoxidase in the milk of breeding mares during the course of lactation]. Milk samples were collected from 44 mares (trotters, warm blood horses, quarter horses) during lactation between the 1st and 90th day p.p. at 20 defined days. The activity of the enzymes LDH, gamma-GT, GOT, GPT and lactoperoxidase was investigated. The aim of this study was to find out the changes of these parameters during lactation and whether an influence of race, conception, date of foaling, age and number of lactations existed on the enzyme activities in mare's milk. The following results were obtained: In mare's milk the LDH-activity was highest (xg = 629 x 1.5 +/- 1 U/l) on the 1st day ...
Interindividual variation in total and carrier-mediated lactate influx into red blood cells. To study in standardbred horses interindividual variation in the influx of lactate into red blood cells, venous blood samples were collected from 89 horses from 2 wk to 9 yr of age. For 62 horses, the rate of influx was normally distributed with a mean rate of 4.09 nmol.mg protein-1.min-1 at a lactate concentration of 10 mM, and the respective value for the other 27 horses was 0.58 nmol.mg protein-1.min-1. At 30 mM of lactate, the rates were 8.71 and 1.97 nmol.mg protein-1.min-1, respectively. This bimodal distribution was independent of age. In horses with high transport activity, the monocar...
Experimental cyathostome challenge of ponies maintained with or without benefit of daily pyrantel tartrate feed additive: comparison of parasite burdens, immunity and colonic pathology. Eighteen mixed-breed, naturally infected ponies ranging in age from 1 to 16 yr and four cyathostome-naïve ponies reared and maintained under parasite-free conditions ranging in age from 1 to 4 yr were used in this study. Naturally-infected ponies were treated with 1 dose of ivermectin (IVM) at 200 micrograms kg-1, followed by a 5-day regimen of oxibendazole (OBZ) at 20 mg kg-1 to remove existing cyathostome burdens; cyathostome-naïve control ponies were treated with IVM alone. The naturally infected ponies were matched on age and gender, then randomly assigned to one of three treatment group...
Clinical biochemical parameters of the endangered Catalonian donkey breed: normal values and the influence of sex, age, and management practices effect. Twelve clinical biochemical parameters were determined in 97 animals of all age groups and both sexes of the endangered Catalonian donkey breed. Significant sex differences were observed for phospholipid concentration (P<0.01). Evaluating the effect of management practices on the various parameters showed significant differences for total bilirubin (P<0.001) and creatinine (P<0.05) concentrations and gamma-glutamyltransferase (P<0.05) activity. Moreover, it was observed that inorganic phosphorus concentration decreased with age (P<0.001), whereas albumin and triglyceride concent...