Omneity® Pellets
All-In-One Vitamin & Mineral Pellet
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.
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...
Effects of age, season, and fertility status on plasma and intratesticular immunoreactive (IR) inhibin concentrations in stallions. The nature of the relationship between inhibin and reproductive function in the stallion is yet to be elucidated. Blood and testes from 51 light horse stallions ranging in age from 2 mo to 25 years were collected during the breeding and nonbreeding seasons to study the effects of testicular maturation, aging, season, and fertility status on peripheral and intratesticular concentrations of Ir inhibin and other reproductive hormones. Of the 51 stallions, 12 age-matched stallions (6 fertile, 3 subfertile, and 3 infertile) were used in the fertility study. Blood samples were taken before castratio...
The distribution of cartilage oligomeric matrix protein (COMP) in tendon and its variation with tendon site, age and load. A protein prominent in guanidine hydrochloride extracts of adult bovine and equine digital flexor tendons was confirmed to be Cartilage Oligomeric Matrix Protein (COMP) by non-reducing and reducing SDS-PAGE, reaction with rabbit anti-COMP polyclonal antiserum on Western blots, trypsin digestion followed by HPLC on a C2/C18 column, and identification of COMP mRNA from tendon on Northern blots. Immunohistochemistry and Western blots of extracts showed COMP to be present in all regions of digital flexor tendons. Equine tendon COMP was purified by ion exchange chromatography and gel filtration and...
Is the thoroughbred race-horse under chronic stress? Thoroughbred fillies were divided into three groups according to age: group 1, 7 fillies aged 1 to 2 years (G1) starting the training program; group 2, 9 fillies aged 2 to 3 years (G2) in a full training program; group 3, 8 older fillies 3 to 4 years of age (G3) training and racing. Blood samples were collected weekly from July to December. Cortisol was quantified using a solid phase DPC kit. The intra- and interassay coefficients of variation were 12.5% and 15.65% and sensitivity was 1.9 +/- 0.2 nmol/l. The semester average of cortisol levels varied between groups: G1 = 148.8 +/- 6.7, G2 = 12...
Relationship between race start characteristics and risk of catastrophic injury in thoroughbreds: 78 cases (1992). To investigate relationships of several racehorse characteristics and race conditions with risk of a catastrophic musculoskeletal injury (CMI) resulting in euthanasia in Thoroughbreds during racing in California in 1992. Methods: Retrospective longitudinal study. Methods: Thoroughbreds that incurred CMI during racing and all California race entrants in 1992. Methods: Necropsy records were reviewed, and race start information was obtained. Incidence risk of CMI/1,000 race entrants was estimated. Relationships between CMI during racing and race-meet, entrant age and sex, race type and length, an...
Morphometric study of the equine navicular bone: comparisons between fore and rear limbs. Navicular bones collected from the four limbs of 95 sound horses were studied. The anatomic bases have been laid down about morphometry of the navicular bones and their variations according to limbs, after corrections have been made for morphologic type, gender, weight, size and age. All the dimensions of the navicular bone (except for the thickness) were larger in the fore limb. This phenomenon probably reflects an attempt to compensate for the greater forces exerted upon the fore limbs during exercise and at rest. Navicular bones collected from the four limbs of 61 sound horses were studied ...
Ageing of equine articular cartilage: structure and composition of aggrecan and decorin. In order to identify the pathological processes involved in the destruction of articular cartilage in arthritic diseases, it is first necessary to characterise the normal homeostasis of cartilage in a healthy joint. In particular, normal age-related changes in the biochemistry of cartilage complicate any comparisons that are made between diseased and healthy tissue. There are, however, no reports in the literature detailing the influence of ageing on the biochemistry of proteoglycans in equine articular cartilage. This study addresses the absence of such information by investigating the struct...
The pharmacokinetics of cefadroxil over a range of oral doses and animal ages in the foal. To evaluate the effect of foal age on the pharmacokinetics of cefadroxil, five foals were administered cefadroxil in a single intravenous dose (5 mg/kg) and a single oral dose (10 or 20 mg/kg) at ages of 0.5, 1, 2, 3 and 5 months. Pharmacokinetic parameters of terminal elimination rate constant (beta(po)), oral mean residence time (MRTpo), mean absorption time (MAT), rate constant for oral absorption (Ka), bioavailability F, peak serum concentrations (Cmax) and time of peak concentration (tmax), were evaluated in a repeated measures analysis over dose. Across animal ages, parameters for the in...
Prospective study of equine colic risk factors. A 1 year prospective study was conducted on 31 horse farms to identify risk factors for equine colic. Farms were randomly selected from a list from 2 adjacent counties of Virginia and Maryland, USA. The association between colic and farm or individual horse risk factors related to management, housing, pasture, use, nutrition, health and events was first examined by univariate statistical analysis. Individually significant (P < = 0.25 for farm factors, P < = 0.10 for horse factors) variables were used in a stepwise multivariable forward logistic regression to select explanatory factors (P...
The effect of age and diet on the oral glucose tolerance test in ponies. To evaluate the effects of age and diet on the oral glucose tolerance test (OGTT) in healthy ponies, OGTTs were performed on 2 groups of British native breed ponies (Group A: 7 foals [6-9 months], Group B: 7 mature individuals [6-13 years]) when maintained on either a high fibre pelleted ration only (Groups A and B) or a hay only diet (Group B). Plasma glucose response, following oral glucose administration, for Group A (basal plasma glucose concentration [Glu0] 4.6 +/- 0.4 mmol/l (mean +/- s.d.) increasing to 11.5 +/- 1.3 mmol/l at 90 min) was significantly different (P < 0.05) from that o...
Prospective study of equine colic incidence and mortality. A prospective study of one year was conducted on 31 horse farms to obtain population based estimates of incidence, morbidity and mortality rates of equine colic. Farms with greater than 20 horses were enrolled by randomly selecting horse owners from 2 adjacent counties of Virginia and Maryland. Descriptive information for 1427 horses was collected at the initiation of the study and updated at 3 month intervals. Time on the farm during the study was tabulated for each horse. When colic was reported by the owner, investigators visited the farm to obtain information about the colic. The crude inc...
