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.
The efficacy of a single chain recombinant equine luteinizing hormone (reLH) in mares: induction of ovulation, hormone profiles, and inter-ovulatory intervals. The objectives of this study were to determine the efficacy of recombinant equine luteinizing hormone (reLH) in shortening the time to ovulation in cycling mares and to determine the effects of treatment on endogenous hormones and inter-ovulatory intervals. In study 1, mares of light horse breeds (3-20 years) were treated with either a vehicle, various doses of reLH, or human chorionic gonadotropin (hCG). Cycling mares were examined by palpation and ultrasound per rectum daily or every 12h from the time of treatment to ovulation. In studies 2 and 3, jugular blood samples were collected daily o...
Negative effect of estradiol on luteinizing hormone throughout the ovulatory luteinizing hormone surge in mares. The negative effect of estradiol-17beta (E2) on LH, based on exogenous E2 treatments, and the reciprocal effect of LH on endogenous E2, based on hCG treatments, were studied throughout the ovulatory follicular wave during a total of 103 equine estrous cycles in seven experiments. An initial study developed E2 treatment protocols that approximated physiologic E2 concentrations during the estrous cycle. On Day 13 (ovulation = Day 0), when basal concentrations of E2 and LH precede the ovulatory surges, exogenous E2 significantly depressed LH concentrations to below basal levels. Ablation of all f...
eFSH in clinical equine practice. Equine follicle stimulating hormone (eFSH) has been used to induce follicular development in transitional mares and problem acyclic mares, as well as superovulate cycling mares. The most efficacious protocol is to administer 12.5 mg eFSH, intramuscularly, twice daily beginning 5 to 7 days after ovulation when the diameter of the largest follicle is 20 to 25 mm. Prostaglandins are to be administered on the second day of eFSH therapy. Treatment with eFSH is continued for 3 to 5 days until follicle(s) are >or=35 mm in diameter. The mare is subsequently allowed to 'coast' for 36 h, after which hum...
Postmortem diagnosis of idiopathic hyperammonemia in a horse. A 6-year-old Quarter Horse stallion was referred to Oklahoma State University Veterinary Medical Teaching Hospital for evaluation of abdominal pain that developed after breeding activity earlier in the day. The horse developed diarrhea and progressively worsening neurologic signs (circling, ataxia, head pressing) within 22 hours of presentation and was subsequently euthanized due to severe self-destructive behavior. Antemortem biochemical and hematologic abnormalities included hypocalcemia but no evidence of hepatic disease. Idiopathic hyperammonemia and encephalopathy were suspected; cerebros...
Continuous administration of low-dose GnRH in mares I. Control of persistent anovulation during the ovulatory season. Three experiments were conducted during the operational breeding season to confirm that continuous, subcutaneous infusion of low-dose GnRH would not disrupt established estrous cycles (Experiment 1), and test the hypotheses that a similar treatment would stimulate secretion of LH and induce development of ovulatory follicles in persistently anovulatory mares (Experiments 2 and 3). Treatment with GnRH (5 microg/h) increased (P<0.001) serum P4 during the luteal phase (7.7+/-0.5 versus 6.4+/-0.5 ng/mL), tended to increase serum LH (2.6+/-0.27 versus 1.9+/-0.25 ng/mL), and did not modify intero...
Intra-abdominal adhesions in horses: a retrospective evaluation of repeat laparotomy in 99 horses with acute gastrointestinal disease. The objectives of this study were (1) to determine the prevalence of pathological abdominal adhesion formation following exploratory laparotomy; (2) to establish the site of adhesion formation and its relationship to the initial lesion; (3) to ascertain whether the development of intra-abdominal adhesions decreases long-term survival and (4) to identify risk factors for adhesion formation. Of 1014 horses treated surgically for acute gastrointestinal disease, 113 (10.1%) were subjected to repeat laparotomy, with surgical records available for 99 of these cases. Pathological adhesions were the m...
Potential involvement of EGF-like growth factors and phosphodiesterases in initiation of equine oocyte maturation. Human chorionic gonadotropin (hCG) was administered to mares in estrus with large, dominant ovarian follicles to initiate follicular and oocyte maturation. Follicular contents were collected at 0, 2, 4 and 6 h after hCG. Epiregulin, amphiregulin and phosphodiesterase (PDE) mRNA contents of granulosa cells (PDE 4D) were determined by reverse transcription and real-time PCR; PDE 3A mRNA content of single oocytes was determined similarly. Copy numbers of mRNA did not increase for PDE 3A or 4D over the time interval studied. Amounts of epiregulin and amphiregulin mRNA were correlated (r=0.98) when...
Equestrian injuries: incidence, injury patterns, and risk factors for 10 years of major traumatic injuries. Horseback riding is more dangerous than motorcycle riding, skiing, football, and rugby. The purpose of this study was to identify the incidence and injury patterns, as well as risk factors associated with severe equestrian trauma. Methods: All patients with major equestrian injuries (injury severity score > or = 12) admitted between 1995 and 2005 were reviewed. A 46-question survey outlining potential rider, animal, and environmental risk factors was administered. Results: Among 7941 trauma patients, 151 (2%) were injured on horseback (mean injury severity score, 20; mortality rate, 7%). In...
Metabolic and clinical traits in horses undergoing feed deprivation for elective orthopaedic surgery. The objective of this study was to investigate some metabolic and clinical effects of feed deprivation in horses that were submitted for orthopaedic surgery. The effects of preoperative feed restriction were investigated in 20 horses submitted for elective orthopaedic surgery. The patients were fasted from 12 hours before until 4 hours after surgery. Serum free amino acids, glucose,free fatty acids (FFA), white blood cell counts, creatine kinase (CK) and aspartate aminotransferase (AST) were determined 24 hours before surgery, 2 hours after the end of anaesthesia and 24 and 72 hours after surg...
Temporal relationships among LH, estradiol, and follicle vascularization preceding the first compared with later ovulations during the year in mares. Diameter of the preovulatory follicle, plasma concentrations of LH and estradiol, and vascularization of the follicle wall, based on color-Doppler signals, were characterized in 40 pony mares for 6 days preceding ovulation (Days -6 to -1; preovulatory period). Comparisons between the preovulatory periods preceding the first compared with a later ovulation during the year were used to study the relationships between LH and estradiol and between vascularization and estradiol. Diameter of the preovulatory follicle was greater (P<0.02) and concentration of LH was less (P<0.02) during the fir...
Cryptorchidism in common eutherian mammals. Cryptorchidism is failure of one or both testes to descend into the scrotum. Primary fault lies in the testis. We provide a unifying cross-species interpretation of testis descent and urge the use of precise terminology. After differentiation, a testis is relocated to the scrotum in three sequential phases: abdominal translocation, holding a testis near the internal inguinal ring as the abdominal cavity expands away, along with slight downward migration; transinguinal migration, moving a cauda epididymidis and testis through the abdominal wall; and inguinoscrotal migration, moving a s.c. cauda...
Plethysmographic comparison of breathing pattern in heaves (recurrent airway obstruction) versus experimental bronchoconstriction or hyperpnea in horses. Horses with recurrent airway obstruction (heaves) are described as exhibiting "increased abdominal effort," but it is unknown whether this translates to an effective contribution to ventilation. Objective: We hypothesized that heaves is characterized by asynchrony between rib cage and abdominal motions, and that the abdominal component is the major contributor to ventilation. Methods: The rib cage versus abdominal motion in naturally occurring heaves (n = 15) was compared to controls at rest (n = 7) and during hyperpnea because of lobeline treatment, and the effects of histamine-induced bronch...
Molecular cloning of equine 17beta-hydroxysteroid dehydrogenase type 1 and its downregulation during follicular luteinization in vivo. The type 1 form of 17beta-hydroxysteroid dehydrogenase (17betaHSD1) was the first isoform to be identified and is capable of converting estrone to 17beta-estradiol. This study was aimed at characterizing the molecular structure of the equine 17betaHSD1 gene and cDNA, as well as its molecular regulation during human chorionic gonadotropin (hCG)-induced follicular luteinization/ovulation in vivo. The equine 17betaHSD1 gene was cloned from an equine genomic library and shown to have a conserved genomic structure composed of six exons. Its cDNA sequence was also identified and coded for a 308 amin...
Predisposing factors for small colon impaction in horses and outcome of medical and surgical treatment: 44 cases (1999-2004). To identify factors associated with development of small colon impaction in horses and with selection of medical versus surgical treatment and to determine the prognosis for affected horses following medical or surgical management. Methods: Retrospective case series. Methods: 44 horses with primary impaction of the small colon. Methods: Medical records were reviewed for signalment, history, clinical findings, treatment (medical vs surgical), hospitalization time, and outcome. For comparison purposes, the same information was collected for 83 horses with primary impaction of the large colon. Re...
Strategies for construction of luteinizing hormone beta subunit analogs with carboxyl terminal extensions in non-primate, non-equid mammalian species. Chorionic gonadotropins (CG) are unique because they have a carboxyl terminal peptide (CTP) extension on their beta subunits that prolongs circulatory survival. CGbeta genes from the human being and horse have evolved from ancestral luteinizing hormone (LH) beta genes by different pathways that involve deletions that change the reading frames and yield a CTP. Here we further review our previous analysis, aimed at determining whether LHbeta genes in non-primate, non-equid species inherently possess DNA sequences that encode CTP-like domains. In multiple mammalian species, simple frame-shift mut...
Expression and bioactivity of a single chain recombinant equine luteinizing hormone (reLH). To study structure-activity relationships and the role of equine gonadotropins in the normal and pathophysiology of equine reproduction, the availability of purified hormones is essential. Previous expression studies in transfected CHO cells showed inefficient assembly of the human and bovine alpha and beta subunits, resulting in low levels of recombinant LH. The ability to express a single chain bearing genetically linked alpha and beta subunits bypasses this rate-limiting assembly step. A chimera was constructed by overlap PCR in which the carboxy terminal end of the eLHbeta subunit was gene...
Equine histoplasmosis presenting as a tumor in the abdominal cavity. A 3.5-year-old Thoroughbred mare presented at necropsy with a large mass at the root of the mesentery and multiple smaller mesenteric masses. The mucosa of the small intestine contained numerous raised nodules. Histologic examination revealed severe granulomatous mesenteric lymphadenitis and enteritis. Epithelioid macrophages and multinucleated giant cells frequently contained numerous intracytoplasmic yeast organisms, which were strongly positive on immunohistochemical staining when using a polyclonal antibody against Histoplasma spp. A diagnosis of abdominal histoplasmosis was made based on ...
Evaluation of three equine FSH superovulation protocols in mares. Superovulation could potentially increase embryo recovery for immediate transfer or cryopreservation. The objectives were to evaluate the effect of pretreatment with progesterone and estradiol (P+E) on follicular response to eFSH and compare doses of eFSH and ovulatory agents on follicular development and ovulation in mares. In Experiment 1, 40 mares were assigned to one of four treatment groups. Group 1 consisted of untreated controls. Group 2 mares were administered eFSH without pretreatment with P+E. Group 3 mares were administered P+E for 10 days starting in mid-diestrus followed by eFSH t...
Cardiopulmonary effects of buprenorphine in horses. To investigate the effects of buprenorphine on cardiopulmonary variables and on abdominal auscultation scores in horses. Methods: 6 healthy adult horses. Methods: Horses were restrained in stocks and allocated to 2 treatments in a randomized crossover design, with 1-week intervals between each treatment. Saline (0.9% NaCl) solution was administered IV as a control, whereas buprenorphine (10 mug/kg, IV) was administered to the experimental group. Cardiopulmonary data were collected for 120 minutes after buprenorphine or saline solution administration. Abdominal auscultation scores were monitore...
Follicle selection in cattle and horses: role of intrafollicular factors. The eminent event in follicle selection during a follicular wave in monovular species is diameter deviation, wherein one follicle continues to grow (developing dominant) and other follicles (subordinates) begin to regress. In cattle, the IGF system, oestradiol and LH receptors are involved in the intrafollicular events initiating deviation as indicated by the following: (1) concentrations of free IGF-I and oestradiol in the follicular fluid and number of LH receptors in the follicular wall increase more dramatically in the future dominant follicle than in the future subordinate follicles befor...
Follicle deviation and diurnal variation in circulating hormone concentrations in mares. The temporal relationships between follicle deviation and systemic hormone concentrations were studied in mares. Blood samples were obtained at 01:00, 07:00, 13:00, and 19:00 h from nine mares throughout an interovulatory interval. Diurnal variation in progesterone occurred on Days 4-12 and in LH on Days 4 and 5; the lowest concentration for both hormones was at 13:00 h. Ultrasonically observed deviation in the ovulatory follicular wave began on Day 15.7+/-0.5 (ovulation=Day 0). An increase (P<0.002) in LH began on Day 14 before the beginning of deviation, and an increase (P<0.05) in est...
Panniculitis in a horse with peripancreatitis and pancreatic fibrosis. A 22-year-old pinto mixed breed mare was admitted for evaluation of severe colic signs and gastric reflux. Multiple nonpainful, variably sized hard masses were palpated in the subcutis over the thorax, abdomen, and hindquarters of the horse. The mare was diagnosed with sterile peritonitis and had systemically high gamma-glutamyltransferase, amylase, and lipase. Three days into treatment she became febrile with signs of persistent and mild abdominal discomfort; euthanasia was elected. Necropsy revealed peripancreatitis, pancreatic fibrosis, abdominal steatitis and panniculitis. Panniculitis ass...
Infections in the equine abdomen and pelvis: perirectal abscesses, umbilical infections, and peritonitis. This article addresses the pathophysiology, diagnosis, management, and prognosis of several different infections within the equine abdomen and pelvic region. The latest advances in the diagnosis and treatment of perirectal abscesses, umbilical infections, and local and diffuse peritonitis are discussed. Emphasis is placed on recent advances in diagnostics and therapeutics with reference to human literature that may be useful in equine practice.
Prevalence of gastric squamous ulceration in horses with abdominal pain. Prevalence of gastric ulcerations differs widely according to breed and circumstances of management. Further study of the biological variables involved is required in order to identify more exactly the reasons for the reported range. Objective: The objectives of this present study, which do not appear to have been addressed previously in the literature, were 1) the prevalence of gastric ulceration in horses with abdominal pain. 2) difference in prevalence in horses responding to medical therapy and those requiring surgical intervention. 3) whether gastric ulceration is associated with any part...
A preliminary study on the induction of dioestrous ovulation in the mare–a possible method for inducing prolonged luteal phase. Strong oestrous symptoms in the mare can cause problems with racing, training and handling. Since long-acting progesterone treatment is not permitted in mares at competition (e.g. according to FEI rules), there is a need for methods to suppress unwanted cyclicity. Spontaneous dioestrous ovulations in the late luteal phase may cause a prolongation of the luteal phase in mares. Methods: In this preliminary study, in an attempt to induce ovulation during the luteal phase, human chorionic gonadotropin (hCG) (3000 IU) was injected intramuscularly in four mares (experimental group) in the luteal pha...
Superovulation in mares. Embryo recovery from single ovulating mares is approximately 50 per cent per estrous cycle. Superovulation could be used to increase embryo recovery and provide extra embryos for embryo freezing. This review addresses some historical approaches to superovulation, as well as examines factors that affect the response of mares to equine FSH. eCG, GnRH and inhibin vaccines have been of limited success in stimulating multiple ovulation. Numerous studies have shown that injection of equine pituitary extract (EPE) will result in three to four ovulations per estrous cycle and two embryos. A purified, ...
Human chorionic gonadotropin-dependent induction of an equine aldo-keto reductase (AKR1C23) with 20alpha-hydroxysteroid dehydrogenase activity during follicular luteinization in vivo. Aldo-keto reductases (AKRs) are multifunctional enzymes capable of acting on a wide variety of substrates, including sex steroids. AKRs having 20alpha-hydroxysteroid dehydrogenase (20alpha-HSD) activity can reduce progesterone to 20alpha-hydroxy-4-pregnen-3-one (20alpha-DHP), a metabolite with lower affinity for the progesterone receptor. The objective of this study was to investigate the regulation of equine AKR1C23 during human chorionic gonadotropin (hCG)-induced ovulation/luteinization. The equine AKR1C23 cDNA was cloned and shown to encode a 322 amino acid protein that is conserved (71-81...
Use of transabdominal ultrasonography to determine the location of cryptorchid testes in the horse. Transrectal ultrasonography is a reliable technique to identify intra-abdominal testes, but can be hazardous or impractical in fractious, juvenile or small equids. The transabdominal approach therefore requires validation. Objective: To evaluate the sensitivity and specificity of transabdominal ultrasonography to localise cryptorchid testes. Methods: Thirty-eight horses admitted for cryptorchidism underwent transabdominal ultrasonography to locate errant testes. Location of the testes was confirmed during surgery (n = 37) or necropsy (n = 1). Results: Horses weighed 175-760 kg. Twenty-two test...