Topic:Abdominal
Research in the abdominal health and conditions category examines digestive physiology, gastrointestinal disorders, and treatment protocols in horses. This page compiles peer-reviewed studies and journal articles on the pathophysiology of common digestive issues, diagnostic techniques for conditions like colic and gastric ulcers, and evaluations of various treatment strategies.
Radioimmunoassay and in-vitro bioassay of serum LH throughout the equine oestrous cycle. Mares were bled once daily throughout a cycle, or 3 times daily from the first day of oestrus to the 2nd day after ovulation. LH was measured by heterologous radioimmunoassay and by an in-vitro bioassay based on LH-stimulated testosterone production by mouse Leydig cells. The patterns of bio- and immuno-active LH during the oestrous cycle were similar but not identical, so that in both groups of mares the ratio of biological: immunological (B:I) activity during the LH surge was significantly higher before than after ovulation (P less than 0 . 001). Considerable individual variation in cycle me...
Importance of testicular hormones in maintaining the annual pattern of LH secretion in the male horse. Serum LH was measured by radioimmunoassay in 5 long-term (greater than or equal to 3 years) castrated male horses bled at 30-min intervals for 2 h twice a month from March to February. There was no significant effect of month on LH levels; however, mean levels were significantly lower in spring than autumn (P less than 0.05). By contrast, stallions in the same environment showed a markedly seasonal pattern of LH secretion, with LH rising at the onset of the breeding season to reach levels in late spring 3-4 times those in early winter. Despite differences in seasonal patterns of secretion, ann...
Pituitary and chorionic gonadotrophic control of ovarian function during early pregnancy in equids. Concentrations of FSH, LH, chorionic gonadotrophin (CG) and progesterone were measured during early pregnancy in mares and donkeys carrying normal intraspecies and transferred extraspecies conceptuses. A secondary rise in progesterone concentrations occurred in normal intraspecies horse and donkey pregnancy soon after the appearance of CG but FSH concentrations continued to fluctuate and were not influenced by CG production. In donkeys carrying transferred horse conceptuses FSH concentrations fell sharply and progesterone concentrations rose steeply, coincidental with the appearance of abnorma...
Comparison of the interaction of equine LH and human chorionic gonadotrophin to equine testicular receptors. Human chorionic gonadotrophin (hCG) can be used to study horse luteinizing hormone (LH) receptors in stallion testicular tissue. hCG was more stable than horse LH during radioiodination when compared by their abilities to bind to testicular receptor sites. During incubation, neither hormone lost binding activity at 4 degrees C. Horse LH lost binding activity during incubation at 25 degrees C and both hormones lost binding activity at 37 degrees C. Both hormones bound to the same receptor sites which are specific for the hormones. The receptor sites were not degraded when incubated at 4 degrees...
Effect of PGF-2 alpha on LH receptors in the equine corpus luteum. As quantified by Scatchard analysis, a 27 000 g crude luteal membrane fraction contained a single population of unoccupied LH receptors characterized by high affinity, ka = 0.647 +/- 0.158 X 10(11) M-1 and low binding capacity, Rt = 4.91 +/- 0.78 X 10(-11) M/mg membrane fraction. Acceptable hormonal specificity, reversibility, saturability, high affinity and tissue specificity indicated that the binding protein was a physiological receptor. To ensure that the methods used for Scatchard analysis were valid, hCG was characterized for specific activity and maximum bindability, non-specific bindin...
Effect of manipulating central catecholamines on puberty and the surge of luteinizing hormone and gonadotropin releasing hormone induced by pregnant mare serum gonadotropin in female rats. We have investigated the effect of manipulating central catecholamines on the timing of puberty (as assessed by vaginal opening) in female rats and the surge of luteinizing hormone (LH) and gonadotropin releasing hormone (GnRH) induced by pregnant mare serum gonadotropin (PMSG) in immature female rats. Manipulation of the catecholamines was carried out with either 6-hydroxydopamine (6-OHDA) administered with or without either desipramine (DMI) or pargyline, or alpha-methyl-p-tyrosine (alpha-MPT). The neonatal administration of 6-OHDA delayed puberty, an effect which was potentiated by pretreat...
Origin an importance of increased alkaline phosphatase activity in peritoneal fluids of horses with colic. The origin of increased alkaline phosphatase (ALP) activity in peritoneal fluid (PF) of horses with clinical signs of abdominal pain was investigated to determine the usefulness of measuring ALP in PF in the diagnosis of small intestinal injury. The ALP isoenzymes in PF from 10 clinically normal horses and from 50 horses with clinical signs of acute abdominal pain were analyzed for their sensitivities to inhibition by L-phenylalanine, L-homoarginine, and levamisole and to inactivation by heat (56 C, 15 minutes). The enzymes also were discriminated by their patterns of migration during polyacry...
Physico-chemical properties of pregnant mare serum gonadotropin. Pregnant mare serum gonadotropin exhibits a dissociation at acid pH as shown by the drop of s20,w values from 3.52 S at pH 8.1 to 2.52 S at pH 2.0. The dissociation is accompanied by an absorbance change with a maximum at 287 nm and a parallel loss of both follicle-stimulating hormone (FSH) and luteinizing hormone (LH) activities as followed by radioreceptor assays. The apparent pKa of the acid transition is 3.45 with an extremely slow and temperature-dependent rate at pH 2.0 (1.8 . 10(-4) s-1 at 37 degrees C). By gel filtration the molecular weight of the active hormone is estimated to be 45 ...
Obstruction of the small colon by intramural haematoma in three horses. Three cases of intramural haematoma of the small colon of horses are presented. In all cases the haematoma obstructed the lumen and caused an accumulation of faeces and gas. The horses were in shock and had acute abdominal pain. Exploratory abdominal surgery revealed the haematomas and showed them to be associated with chronic infection and terminal rupture in one animal which was subsequently killed, and an iatrogenic perforation of the terminal small colon in another which survived after intestinal resection. In the remaining horse, which died without recovering after intestinal resection, n...
Intestinal infarction associated with mesenteric vascular thrombotic disease in the horse. Intestinal infarction associated with cranial mesenteric artery thrombosis, without strangulation obstruction of the intestine, was studied in 18 horses. Findings normally of value in evaluating horses with acute abdominal pain (heart rate, rectal palpation findings, gastric reflux) or classification of the degree of pain were not helpful in diagnosing the problem. Similarly, packed cell volume, plasma total protein, circulating white blood cell count, peritoneal white blood cell count, and peritoneal fluid total protein were not of value in predicting severity of the intestinal damage, locati...
Torsion of the spermatic cord in a horse. A 360-degree torsion of the left spermatic cord was diagnosed in a 2 1/2-year-old Quarter Horse colt. Clinical signs included abdominal discomfort, with slight elevations in heart and respiratory rates. The scrotum on the left side was moist and edematous. The left testicle was enlarged, firm, and retracted slightly toward the abdominal cavity. The colt resented palpation of the testicle. On rectal palpation, the left vaginal ring and the structures passing through the ring were edematous and painful to pressure. Surgical correction was achieved by emasculation. The tail of the epididymis and ...
[An uncommon cause of colic (author’s transl)]. A rare case of colic in an eleven-year-old New Forrest mare is reported. As treatment was ineffective, the animal had to be slaughtered. Post mortem examination showed that the colic was due to bilateral haemorrhagic corpus luteum, from which blood (appr. 20 liter) entered the abdominal cavity.
Variations in the properties of equine chorionic gonadotropin. The objectives of this paper are to review the chemical and biological properties of equine chorionic gonadotropin (eCG, PMSG) isolated from the serum. Comparisons are made with eCG isolated from endometrial cups, trophoblast cell culture medium, and low titer serum. The results show that eCG can vary, depending on the source, in both chemical and biological (LH and FSH activity) properties.
The effects of Clostridium perfringens type A enterotoxin in Shetland ponies–clinical, morphologic and clinicopathologic changes. Severe abdominal pain, classic colic signs and hemorrhagic gastro-entero-cecocolitis were induced in three conventional Shetland ponies by intravenous injection with Clostridium perfringens Type A enterotoxin. Histological examination showed marked congestion, edema and hemorrhage of the large and small intestine and sloughing of the tips of the intestinal villi. Marked vacuolar degeneration of hepatocytes with dilatation of the spaces of Disse also was found. Clinical changes consisted of severe hypoglycemia, markedly increased aspartate aminotransferase levels and leukopenia that occurred ra...
Regulation of the estrous cycle in domestic animals– a review. Neuroendocrine and endocrine factors involved in the regulation of reproductive cycles in domestic animals are discussed. Although research data from many species are considered, emphasis is placed on their relevance for the cow, sow, ewe and, to a lesser extent, the mare. Literature cited is not designed to be complete, but rather to be representative of the large volume of material which has been written on the subject.Gonadotropin-releasing hormone is synthesized and secreted in response to various exteroceptive stimuli, but both its release and its effects on the anterior pituitary are mod...
The effect of season on the ovulatory response of Merino ewes to serum from pregnant mares. Groups of 50 ewes were injected with serum from pregnant mares on 5 occasions, 3 months apart, and ovulation rate was estimated at laparoscopy. In Exp. 1, new ewes were used at each time and 3 dose rates (identical to 400, 630 and 1000 i.u. PMSG) were studied. In Exp. 2, the same ewes were used throughout and only 1 dose was given (1000 i.u.). In both experiments the response in ovulation rate of ewes varied significantly throughout the year, with the lowest response in spring (September) and the highest in autumn (March). The ewes in Exp. 2 were as responsive at the end as at the beginning of...
Response of plasma LH and FSH to gonadotropin-releasing hormone in pony foals and ovariectomized pony mares. Plasma FSH and LH response to a synthetic GnRH analog was measured in adult ovariectomized pony mares (OVX) and in pony foals (<70 days of age) during late spring (May-June). FSH and LH responded in a similar fashion (200% increase) in the OVX mare, which is different from other reports for intact mares. There was a greater mean response to a comparable dose of GnRH in the prepubertal foal for both FSH (500%) and LH (900%) than in the OVX mare. There was a positive correlation between age and the maximum FSH response to GnRH in male and female foals. The LH response was positively correlate...
Peritonitis in horses associated with Actinobacillus equuli. Actinobacillus equuli was the cause of peritonitis in 5 horses. In 3 the onset was sudden with intestinal stasis and acute abdominal pain as predominant findings. Two others presented with chronic disease and weight loss. Characteristically the peritoneal fluid had a high nucleated cell count with non-degenerate neutrophils as the predominant cell type. Four horses were treated and recovered.
Purification and characterization of donkey chorionic gonadotrophin. Serum of the pregnant donkey, like that of the mare, contains a gonadotrophin of chorionic origin. The chorionic gonaditrophin of the donkey (dCG) has been isolated in purified form from the serum of pregnant donkeys using methodology previously employed for the purification of pregnant mare chorionic gonadotrophin (eCG). Unlike eCG, dCG is predominatly an LH in biological tests. In the in-vitro rat Leydig cell assay, dCG was as active as eCG, but in the in-vitro rat seminiferous tubule assay for FSH and in the augmentation assay, dCG was considerably less potent than eCG (1-10%). Specific rat...
Estrus, ovulation, and serum hormones in mares given prostaglandin F2 alpha, estradiol, and gonadotropin-releasing hormone. A gonadotropin-releasing hormone (GnRH) was injected in mares given prostaglandin F2 alpha (PGF2 alpha) to induce luteolysis in an attempt to sunchronize ovulation. Pretreatment with estradiol-17 beta (E2-17 beta) was used to determine whether or not estradiol would enhance the release of luteinizing hormone (LH) after treatment with GnRH. Twelve mares were used in a balanced Latin square crossover design. Mares were injected with PGF2 alpha, treatment A; PGF2 alpha mgnRH, treatment B; or PGF2 alpha me2-17 beta mgnRH, treatment C. The interval +/- SEM from PGF2 alpha injection to estrus was 3....