Omneity® Pellets
All-In-One Vitamin & Mineral Pellet
Topic:Veterinary Research
Veterinary research in horses encompasses the study of diseases, health management, and medical treatments specific to equine species. This field investigates various aspects of horse health, including infectious diseases, metabolic disorders, and musculoskeletal conditions. Researchers focus on understanding the pathophysiology of equine ailments, developing diagnostic tools, and evaluating therapeutic interventions. The study of horse health also involves examining preventive measures such as vaccination protocols and nutritional management to promote overall well-being. This page collects peer-reviewed research studies and scholarly articles that explore the diverse areas of veterinary science related to horses, providing insights into disease mechanisms, treatment strategies, and advancements in equine healthcare.
The action of low dose endotoxin on equine bowel motility. Post operative ileus (POI) is a common and serious complication of colic surgery in the horse. There is a high correlation between the incidence of POI and the presence of ischaemic bowel, suggesting a role for endotoxin. 0.1 micrograms/kg endotoxin was administered intravenously to six ponies with chronically implanted gastrointestinal electromechanical recording devices. It produced profound disruption of normal fasting bowel motility patterns, with an inhibition of gastric contraction amplitude and rate, left dorsal colon contraction product and small colon spike rate. In the small intestin...
Soluble oestrogen and progesterone receptors in the endometrium of the mare. Receptors for progesterone and oestrogen were measured in cytosol extracted from the endometrium of mares. Samples of endometrium were obtained from mares during the oestrous cycle and during other physiological and pathological states, and from mares with persistent endometritis. The concentration of binding sites was high around oestrus and early in dioestrus and was low by mid- to late dioestrus. Numbers of receptors were low in mares sampled on Day 15 of pregnancy and in mares in prolonged dioestrus, whereas receptor concentrations in ovariectomized mares were high. In 2 mares with endomet...
Use of a protected catheter brush for culture of the lower respiratory tract in horses with small airway disease. A protected catheter brush introduced by fiberoptic bronchoscopy was used to sample the tracheai and bronchial mucosa in 28 horses with small airway disease. Tracheal and bronchial brushings were examined for the presence of fungi, aerobic and anaerobic bacteria, and a cytoiogical evaluation was also done on fluid collected by the bronchoalveolar lavage (BAL) technique. Microorganisms (bacteria and fungi) were isolated more often in tracheal brushings (53.6%) than in bronchial brushings (10.7%). Anaerobic bacteria were not isolated. Results of this study indicate that fiberoptic bronchoscopy u...
Relationship between circulating tri-iodothyronine and cortisol in the perinatal period in the foal. Pre- and post partum changes in plasma T3 have been examined in relation to plasma cortisol in 23 newborn foals (12 full term, 6 premature and 5 'twilight'), and in 5 fetuses catheterized in late gestation. Blood samples were collected daily from the fetuses and from the neonates at 30-min intervals for 2 h after birth; the plasma was assayed for T3 and cortisol by standard radioimmunoassay methods. In the full-term foals, plasma cortisol and T3 concentrations were high at birth (67.4 +/- 6.1 and 4.3 +/- 0.3 ng/ml respectively) and rose to a maximum during the following 2-h period to 141.0 +/-...
A new method for continuous recording of motor activity in horses. 1. The use of an electronic recorder for the horse motor activity was described. 2. Examples of different types of motor activities are given in Figs 1-8. 3. The ultradian pattern of activity in all records was stressed. 4. The possibility of receiving of more physiological informations by this type of apparatus is discussed.
Late-stage mediators of the inflammatory response: identification of interleukin-1 and a casein-degrading enzyme in equine acute inflammatory exudates. Interleukin-1 and a casein-degrading enzyme have been identified in an experimental system for studying acute inflammation in the horse. The levels of both the cytokine and the proteinase increased over the first 24 hours following initiation of the inflammatory response, and remained at high levels through to the last sample collected at 48 hours. This is in marked contrast to prostaglandin E2 concentrations which were low initially, peaked at four to eight hours and had returned to low levels by 12 to 24 hours. It is likely that interleukin-1 and various proteinases are involved in the later...
Evaluation of an electronic device used as a quick screening method to detect changes in the red cell content of the blood in horses participating in endurance trail rides. Dehydration, to varying degrees, will inevitably occur in horses participating in endurance trail rides. This water loss is directly related to the amount of body water lost through evaporative cooling, that in turn being related to the amount and rate of work performed, and to the environmental temperature and humidity. An electronic apparatus that can substitute for the conventional and time-consuming venous haematocrit was developed to measure the animals' hydration status. The mechanism of this electrometer is based upon the relationship between the red cell content and the electrical cond...
Post-partum ovarian activity in Finnhorse mares with special reference to seasonal effects. In a previous study, times from parturition to the first ovulation were followed in 55 Finnhorse mares on the basis of milk progesterone determinations. Ninety-six per cent of mares had ovulated by day 20 post-partum. If intervals of more than 19 days are excluded from the data, the time from parturition to 1st ovulation was 117 days. However, in cases of foaling before and after the beginning of June the times were 13.0 days and 8.8 days, respectively (p less than 0.001). Long intervals (over 16 days) occurred mainly before 1st May (in 6 out of 7 cases). In a 2nd study, 25 post-partum Finnhor...
Studies of bone marrow and leucocyte counts in peripheral blood in fetal and newborn foals. Clinical and pathological records of 124 foals were studied. The foals were assigned to six groups; normal, premature, dysmature, bacterially infected, neonatal maladjustment syndrome and Equid herpesvirus type 1 (EHV-1) infected. Also, 6 pony fetuses were sampled via catheters in the umbilical vein and artery between 280 and 310 days gestation. Bone marrow aspiration was performed on a further 14 foals. Premature foals had significantly lower neutrophil counts than normal foals up to 5 h. Foals with bacterial infections had significantly lower neutrophil counts up to age 12 h. EHV-1 infected ...
Maturation of oocytes from normal and atretic equine ovarian follicles as affected by steroid concentrations. The ovaries of 23 mares were collected at slaughter during April-June and follicles (4-40 mm in diameter) were dissected and punctured to obtain oocytes for culture. The follicles were grouped according to histology: (a) normal, (b) showing primary and (c) secondary atresia. Antral fluid was analyzed for steroid content; oestradiol and testosterone (but not progesterone or androstenediol) were closely correlated with follicle size and histological state. Oocytes were cultured early after slaughter in Medium 199 (Difco OSI, France) or Medium B2, the highest percentage of oocytes reaching Metaph...
Effect of constant light exposure on circulating gonadotrophin levels and hypothalamic gonadotrophin-releasing hormone (GnRH) content in the ovariectomized pony mare. Melatonin is thought to play a role in relaying photic information to the central nervous system as part of the seasonal reproductive cycle of the mare. However, the mechanisms by which melatonin may act are unknown. Therefore, this study was designed to determine whether exposure to constant light would, by reducing circulating melatonin concentrations, have any effect on hypothalamic gonadotrophin-releasing hormone (GnRH) content and circulating levels of luteinizing hormone (LH) and follicle-stimulating hormone (FSH). Blood samples were collected for 12 h at 15-min intervals from 8 ovariect...
Comparison of bronchoalveolar lavage and respiratory secretion cytology in horses with histologically diagnosed pulmonary disease. Equine bronchoalveolar lavage (BAL) fluid collected from 70 horses and respiratory secretions (RS) obtained from 61 of these horses were evaluated cytologically and grouped according to the histological diagnosis of the lungs from which they were obtained. The histological categories included: normal lung (8 horses); pulmonary eosinophilic infiltration (9 horses); interstitial pneumonia (5 horses); pulmonary hemorrhage (5 horses); and mild (12 horses), moderate (7 horses) and severe (24 horses) chronic small airway disease. In horses with pulmonary disease, all BAL samples and all but one RS s...
[CEA test in domestic animals]. In human cancer treatment, CEA (carcino embryonic antigen) testing is a routine procedure, even though the test is of low sensitivity (40%) and low specificity (70%). Since tests with polyclonal antibodies render no reproducible results with animal sera, the applicability of a recently available monoclonal CEA test designed for human sera was evaluated. We were able to show that the latter test was of supplemental diagnostic value when testing animal sera. The upper normal limit for dogs is 1.65 ng/ml, for cats 2.81 ng/ml, for cows 2.85 ng/ml, for sheep 2.85 ng/ml and for horses 1.61 ng/ml.
Direct effects of free and conjugated steroids on GnRH stimulated LH release in cultured equine anterior pituitary cells. Enzymatically dispersed anterior pituitary cells from donor mares were cultured for 48 h in alpha-modified Eagles' medium containing 10% steroid-free horse serum. The cells were then incubated for 24 h in fresh medium oestrogen followed by a 4-h incubation with or without GnRH. Media and cell extracts were analyzed for LH by radioimmunoassay. In the first series of experiments, pituitary cells from Day-3 dioestrous mares were preincubated with ethanol (control) or different concentrations of E2 (10(-11) to 10(-7) M) for 24 h prior to a 4-h incubation without (basal) or with 1.0 nM GnRH. E2 inc...
Follicular and endocrine responses of anoestrous mares to administration of native GnRH or a GnRH agonist. Thirty-seven seasonally anoestrous mares were divided into treatment and control groups and given 10 micrograms of native GnRH (GnRH) per hour using a peristaltic pump, or 10 micrograms GnRH agonist (GnRHa) twice daily, beginning on either 13 January, 13 February or 14 March. Treatment with GnRH was equally effective in inducing ovulation in January (4/5), February (4/5) and March (3/4). GnRHa treatment was more effective in inducing ovulation in February (4/5) and March (4/4) than in January (2/8). Peak luteinizing hormone (LH) concentrations in mares induced to ovulate with GnRH (7.4 +/- 1.5...
Renal clearance, urinary excretion of endogenous substances, and urinary diagnostic indices in healthy neonatal foals. Urine (U) and serum (S) were obtained every 2 hours during a 12- or 24-hour period from eight healthy 96-hour-old pony or horse foals. Dams' milk samples were obtained concurrently. Urine volume was measured during this 12- or 24-hour period. The mean amount of urine produced was 148 +/- 20 ml/kg/day. Baseline urinalyses were evaluated on all foals at two days of age, before any manipulation. Urine generally was dilute (less than 1.008) but the specific gravity was as high as 1.027 in one normal foal. Continuous (12 or 24 hour) urinary catheterization resulted in bacteriuria but not white bloo...
Plasma progestagens in the mare, fetus and newborn foal. This study used gas chromatography/mass spectrometry (GC/MS) to identify and measure plasma progestagens. The method included deuterated internal standards, e.g. [17,21,21,21-2H]-5 alpha-pregnane-3,20-dione, solid-phase extraction, derivatization (methoxime/t-butyldimethylsilyl) and GC/MS. Full-scan screening identified 3 5-pregnenes, 2 4-pregnenes and 7 5 alpha-pregnanes (no 5 beta-pregnanes). The selected ion mode was used for routine quantitation from calibration curves; response was linear (r greater than 0.98) from 2 to 2000 ng equivalents/ml (0.5 ng/ml method sensitivity) and intra- and ...
In vitro steroidogenesis by granulosa cells from equine pre-ovulatory follicles. Twenty-three follicles were collected from 14 mares on specific days and grouped to represent follicles from early (Group 1; n = 6), mid (Group 2; n = 11) and late (Group 3; n = 6) oestrus, as described previously (Tucker et al., 1988). Isolated granulosa cells (GC) from each follicle were cultured in multiwell plates containing either Eagle's Minimum Essential Medium (MEM) alone, eLH (300 ng/ml), eFSH (300 ng/ml) or eLH + eFSH (300 ng/ml each), in the presence or absence of 0.5 microM testosterone. Media were collected and replaced at 24 h of culture, and 24 h later, media were again collecte...
Paneth cell degranulation and lysozyme secretion during acute equine alimentary laminitis. The equine Paneth cell response to a shift in the microbial balance of the intestinal tract was studied by inducing an acute episode of alimentary laminitis in 6 mature ponies. The normal bacterial population of the gut was modified by administration of a carbohydrate-rich ration. During acute laminitis a dramatic degranulation of the Paneth cells occurred in the intestinal glands throughout the duodenum, jejunum, and ileum. Bacteriocidal lysozyme, which was immunohistochemically identified as a component of the Paneth cell secretory granule, was evident in the glandular lumina and in degranul...
Viability and ultrastructure of equine embryos following culture in a static or dynamic system. The viability and ultrastructure of equine embryos were assessed following culture in a static or perifusion system. The percentage change in diameter was greater (P less than 0.025) for embryos in the static treatment (71%) than in the perifusion treatment (33%). Fluorescein diacetate (FD) scores, the percentage of fluorescing cells (FC) and fluorescent intensity (FI), also were greater (P less than 0.05 and P less than 0.01) following static culture than for embryos cultured in the perifusion system. Four of 9 control embryos resulted in pregnancies but no embryos cultured in either system p...
Non-invasive assessment of the incidences of pregnancy and pregnancy loss in the feral horses of Sable Island. Field observations of 400 totally unmanaged feral horses on Sable Island, Nova Scotia, were complemented by oestrogen determinations in faecal samples from 154 identified females over a 4-year period (454 mare-years). Of mares that were sampled throughout the year and subsequently produced foals, 92.1% exhibited elevated faecal oestrogens between 15 October and 30 March. The results confirm that faecal oestrogens are a useful indicator of pregnancy after approximately 120 days gestation. Distribution of foaling resembled that seen in other feral populations, with 95% of births occurring from A...
In vitro and in vivo studies of equine prolactin secretion throughout the year. In vitro, the prolactin response of perifused anterior pituitary cells of horses to thyrotrophin-releasing hormone (TRH) (0.1, 1.0, 10 and 100 nM), correlated significantly with hours of daylight (P less than 0.01). Baseline concentrations of prolactin also were significantly correlated with daylength (P less than 0.01). When response and baseline data were fitted by nonlinear least squares to a cosine function, the circannual phase was -0.06072 (+/- 0.02170) and -0.05560 (+/- 0.0255), respectively, which are not significantly different from that of daylength. In vivo, prolactin secretion was ...
In vitro comparison of Thoroughbred and Standardbred racehorses with regard to local fatigue failure of the third metacarpal bone. In vitro local fatigue testing of the third metacarpal bone from Thoroughbred and Standardbred racehorses was performed, using fully reversed cyclic bending. Strain number of cycle data were accumulated and indicated that significant difference did not exist between the 2 breeds. It was concluded that the marked difference in the incidence of fatigue failure in the third metacarpal bone (bucked shins, dorsal metacarpal disease) seen in Thoroughbreds and Standardbreds was not related to any differences between the 2 breeds in mechanical properties of the bone.
The corpus luteum: source of oestrogen during early pregnancy in the mare. Thirty pregnant mares were assigned to 3 groups: Group 1 (n = 10) mares served as controls; Group 2 (n = 10) mares were treated with altrenogest (44 mg/day) from Day 16 to 80 and Group 3 (n = 10) mares were treated with a luteolytic dose of PGF2 alpha on Day 16 followed by altrenogest (44 mg/day) until Day 80. Concentrations of progesterone and chorionic gonadotrophin (CG) in plasma and oestrogen conjugate (OC) in urine were determined between Days 16 and 80 of gestation. In Group 3, complete luteolysis occurred in all 10 mares following administration of PGF2 alpha. Six of the 10 mares did no...
Nonlinear algorithm for identification of a fiducial marker for various cardiac events. We report on a nonlinear algorithm which identifies R-wave peaks on the surface electrocardiogram, consistent reference points on the left ventricular pressure waveform and the initiation of the QRS complex on the epicardial electrogram. The algorithm has been used to evaluate data from horses, ponies, dogs and humans at rest and during exercise. It permits rapid, accurate evaluation of data on a beat-by-beat basis even with noisy signals and varying waveform configurations. The algorithm facilitates the acquisition of detailed information previously difficult or impossible to obtain by more c...
Ovarian teratoma and granulosa cell tumor in two mares. Simultaneous and successive occurrence of ovarian teratoma and granulosa cell tumor is reported in 2 mares. Simultaneous occurrence of the tumors may obscure clinical diagnosis. Whereas size, unilaterality, and the cystic nature of each may be similar, differentiating features include the potentially palpable presence of bone, cartilage, or teeth in teratoma, and the hormone-induced behavioral and reproductive effects of granulosa cell tumors. Thorough examination of surgical specimens may reveal the existence of a neoplastic process, previously obscured by the more obvious presence of another...
Effect of interval between doses on response of the pony to sodium bicarbonate. Three pony geldings were given sodium bicarbonate orally in order to study the effect on blood pH and bicarbonate and to determine if frequency of dosing influences the response. In a preliminary study, it appeared that a carry-over effect might occur if the interval between dosing was only 2 days. The ponies received 2 doses of sodium bicarbonate (400 mg/kg) 7 days apart in trial one and then in trial two they received 2 doses of sodium bicarbonate 4 days apart. The sodium bicarbonate was mixed with 2 liters of warm water and given through a nasogastric tube on each trial day. Blood samples w...
Thermophilic and thermotolerant fungi of animals’ hair. Nine thermophilic genera and 17 species in addition to one variety of Aspergillus flavus, Malbranchea pulchella and Humicola grisea were collected from hair samples in Riyadh, Saudi Arabia at 45 degrees C. Fifty-one hair specimens of rabbit, sheep, camel and horse were examined for the presence of thermophilic fungi. The most frequent species were Aspergillus fumigatus, Aspergillus niger, Thermoascus aurantiacus and Malbranchea pulchella var. sulfurea. In low frequency, Aspergillus flavus, Aspergillus quadrilineatus, Paecilomyces variotii, Paecilomyces aerugineus, Mucor pusillus and Rhizopus s...
