Omneity® Pellets
All-In-One Vitamin & Mineral Pellet
Topic:Horses
"Horses" is a broad topic that encompasses various aspects of equine biology, behavior, and management. This category includes studies on the anatomy, physiology, and genetics of horses, as well as their behavior, nutrition, and care. Research in this area may also cover the historical and cultural significance of horses, their roles in agriculture, sport, and therapy, and the challenges associated with their conservation and welfare. The page aggregates peer-reviewed research articles and scholarly studies that explore the multifaceted relationships between humans and horses, examining both scientific and socio-economic perspectives.
Cytogenetic and clinical findings in mares with gonadal dysgenesis. Gonadal dysgenesis in the mare is associated with several different karyotypes, including sex chromosome aneuploidy (63,X; 63,X/64,XX; 63,X/64,XY or 65,XXX), the normal male complement (64,XY) and autosomal deletion (64,XX?del2q-). The 63,X is the most common karyotype found in gonadal dysgenesis. Aneuploid cases probably represent spontaneous chromosome non-disjunction during oogenesis, spermatogenesis or early embryonic development. Cases with XY or autosomal deletion may be inherited defects or of spontaneous origin.
Epidemiology of equine upper respiratory tract disease on standardbred racetracks. The outbreaks of upper respiratory tract infections in horses at Standardbred racetracks were investigated over a three year period. The most serious epidemics of respiratory disease occurred in the winter and spring seasons. Both influenza viruses and equine herpesvirus 1 were shown to be present in the horse population. The herpesvirus was associated with respiratory disease particularly in the winter but the equine influenza viruses apparently were responsible for the major epidemics of respiratory disease at these tracks. Younger horses, two or three years of age, were particularly suscept...
Survival of Haemophilus equigenitalis in different antibiotic-containing semen extenders. The ability of Haemophilus equigenitalis, the causal agent of contagious equine metritis 1977, to survive in various antibiotic-containing semen extenders was studied at different environmental temperatures. Gentamicin sulphate was found to be markedly superior to ampicillin or a combination of sodium benzyl penicillin and polymyxin B sulphate, Semen treated with the former antibiotic was either sterile at cultural examination or else yielded appreciably fewer colonies of H. equigenitalis than the untreated semen control. Ampicillin had no observable effect on the survival of this organism. Ge...
Observations on the length and angle of declination of the vulva and its relation to fertility in the mare. An instrument has been designed to measure the effective length (l) and angle of declination (a) of the vulva in the mare. The product, la, provides an index (Caslick Index) suitable for determining the necessity for Caslick's operation in mares not exhibiting the classical symptoms associated with pneumovagina. The value l showed a significant increase (P less than 0.05) with increased age in breeding mares. Studies on 9020 mares revealed that all caslicked mares, and mares with a Caslick Index of less than 150, had a significantly higher pregnancy rate than non-caslicked mares of similar age...
Internal fixation of fractures of the third phalanx in three horses. The technique of internal fixation of intra-articular fractures of the third phalanx using lag screw interfragmentary compression is described. Three cases are discussed and the successful treatment of infection and osteomyelitis described in one of them. Despite this potential complication internal fixation offers a better prognosis and also a more rapid return to work than non-operative treatments.
[Myocardial changes following experimental protein sensitization]. Guinea pigs were sensitized by three subcutaneous injections of 0.1 ml native horse serum at 2-day intervals, 21 days after the third injection the animals developed marked sensitization to this antigen which was manifested by anaphylactic reaction to the subcutaneous challenge with this antigen. At this time, the myocardium of the sensitized animals showed signs of extra- and intracellular oedema, a sharp increase in the number of lysosomes, damage of their membranes, 2 1/2 months after sensitization the animals showed no anaphylactic reaction to the challenge dose of the antigen. There were ...
Fractures of the proximal sesamoid bones in thoroughbred foals. Eighteen cases of fractures of the proximal sesamoid bones in Thoroughbred foals are described. Most of the fractures were in foals under 2 months old and all but one occurred in the forelegs. The bones commonly fractured when the foal galloped to exhaustion trying to keep up with its dam in the paddock. The types of fracture varied but a simple fracture of the medial sesamoid was most frequent and the majority were towards the base of the bone. Six foals sustained a fracture of more than one sesamoid bone and one foal fractured all 4 proximal sesamoid bones in its front legs. Treatment includ...
Effect of diethylstilboestrol on the relationship between LH, PMSG and progesterone during pregnancy in the mare. Two studies were conducted to determine the relationship between LH and progesterone and between PMSG and progesterone during pregnancy in mares. In the first, samples of jugular blood were collected daily from 7 mares from the first day of oestrus until Day 28 of pregnancy, and in the second, samples were collected weekly from 14 mares from Day 35 of gestation until parturition. In an attempt to prolong secretion of progesterone from accessory corpora lutea, 7 of these 14 mares were injected with increasing doses (2--10 mg) of diethylstilboestrol (DES) between Days 84 and 142 of gestation. Th...
The bacteriological culture of equine uterine contents, in-vitro sensitivity of organisms isolated and interpretation. A total of 19 pathogenic bacterial species was isolated from uterine swabs of 498 out of 1539 mares over 4 years. The swabs were taken by 5 veterinary clinicians using 2 different techniques. Bacterial contamination during swabbing was minimized by scrupulous attention to cleansing of the external genitalia and the perineal area, and in the handling of the culture specimen. The most prevalent organisms isolated were beta-haemolytic streptococcus (39%), Escherichia coli (27%) and Klebsiella pneumoniae (7%). Interpretation of microbiological findings correlated well with clinical findings when n...
[Architectonics of the blood vessels in the wall of the allantoamnion of the mare]. Alantoamnion vascularization was studied on clarified preparations from three mares in advanced pregnancy. Two large blood vessels (artery and vein) beginning from the umbilical vessels were found in the alantoamnion wall. Numerous anastomoses were observed at the passage between the arterial and the vein section. The large arteries had a thick, jely-like vascular wall and snake-like folded lumen. In separate sections of the alantoamnion wall a well developed capillary net was observed consisting of individual particles, polygonal in shape. Vast avascular zones surrounded by numerous vascular ...
An outbreak of contagious equine metritis in 1977 and its effect the following season. An outbreak of contagious equine metritis occurred in Newmarket in 1977. This survey records the effect on fertility of 20 of the stallions which were infected. Swabbing of mares since then has detected 37 carrier mares harbouring the organism, most frequently in the clitoral area. This swabbing programme reduced the incidence of new cases in 1978 to 3 mares and 1 stallion.
The density of equine tissue at 37 degrees C. The density of the following equine tissues was measured: white and grey brain matter, myocardium, lung parenchyma, liver, spleen, gastrointestinal tract and contents, renal medulla and cortex, muscle, fat, tendon and bone. Statistical analysis indicated that there were highly significant differences in the values for density between horses and between tissues within horses. Values for density of eight different muscles were obtained for 18 horses and these were shown to differ highly significantly between horses and between muscles within horses. The values for splenic density differed highly...
DNases in milk and blood sera from different species. DNases were demonstrated in samples of colostrum and blood serum from man and various domestic animals. The measurable DNase activity recorded was highest in samples from cat and dog and lowest in samples from goat, horse, pig and sheep. In contrast to DNases produced by certain bacteria, these enzymes were thermo-labile and the activity was maximal in the area pH 5.0–5.5. A modification of an agar medium originally described for the demonstration of bacterial DNases was found to be suitable for assays of DNases from colostrum, milk and serum. DNaser ble påvist i prøver fra kolostrum og bl...
Treatment of ringworm in horses with natamycin. A suspension based on the antibiotic, natamycin, was applied by sponging to 83 horses of various breeds and ages with signs of clinical ringworm. A number of different causative agents were involved of which Trichophyton equinum was the most common. Treatment successfully eliminated the disease within 4 weeks. After treatment the recovered animals did not show any evidence of re-infection for up to 6 months. The mycological clearance rate was 97 per cent and apart from the efficacy against ringworm, the preparation had the advantage of being non-irritant and odourless. It was also useful for t...
Tendon and ligament from the horse: an ultrastructural study of collagen fibrils and elastic fibres as a function of age. A study has been made of the ultrastructural organization of the collagen fibrils and elastic fibres in tendons and ligaments from horses of ages ranging from 2 months premature to 19 years. Diameter distributions of the collagen fibrils in the common digital extensor tendon, the superficial flexor tendon and the suspensory ligament are unimodal in the foetal tissue and at birth, and at these stages of development the three collagenous tissues are virtually indistinguishable. However, at maturity, the ligament and flexor tendon have bimodal distributions similar to that found for rat-tail tend...
A rapid and simple method for the isolation of pure eosinophilic leukocytes from horse blood. An improved and short method is described for the isolation of intact eosinophilic leukocytes from horse blood with high yield (1--1.5 g/20 l). Viability and purity of the preparations were verified by light and electron microscopy and by the trypan blue exclusion test. Isolated eosinophils were 98--100% pure, intact and viable, and they could be shown to phagocytise immune-complexes.
Shunting in intracranial microvasculature demonstrated by SEM of corrosion-casts. The use of methyl methacrylate corrosion-casts has made it possible to examine the intracranial microvasculature on a three-dimensional scale with the scanning electron microscope. By this means we have compared regions of four cerebral and cerebellar arteries among three domestic animal species. The results of this study suggest that there are from one to three different levels of interarteriolar anastomosis between branches of the same or adjacent vessels. In the horse and ox anastomoses were demonstrated (1) at the level of the precapillary arterioles, (2) along the arterioles, and (3) betw...
Formation of steroids by the pregnant mare. VI. Metabolism of [14C]farnesyl pyrophosphate and [3H]dehydroepiandrosterone injected into the fetus. A mixture of [4,8,12-14C]farnesyl pyrophosphate and [3H]dehydroepiandrosterone was injected into a horse fetus im during laparotomy, after which maternal urine was collected for 6 days. Steroid conjugates in the urine were extracted with Amberlite XAD-2 resin, hydrolyzed, and separated into phenolic and neutral fractions. Estrone, 17 alpha-estradiol, equilin [3-hydroxy-1,3,5(10),7-estratetraen-17-one], and 17 alpha-dihydroequilin [1,3,4(10),7-estratetraene-3,17 alpha-diol] were isolated from the phenolic fraction and their radiochemical purities were established. Only estrone and 17 alpha-estr...
