American journal of veterinary research.
Publisher:
American Veterinary Medical Assn.. Schaumburg, Ill. : American Veterinary Medical Association
Frequency: Monthly
Country: United States
Language: English
Author(s):
American Veterinary Medical Association.
Start Year:1940 -
Identifiers
| ISSN: | 0002-9645 (Print) 1943-5681 (Electronic) 0002-9645 (Linking) |
| NLM ID: | 0375011 |
| (DNLM): | A25065000(s) |
| (OCoLC): | 01480202 |
| Coden: | AJVRAH |
| LCCN: | 42050041 |
| Classification: | W1 AM53 |
Evaluation of a single intra-articular injection of autologous protein solution for treatment of osteoarthritis in horses. To evaluate intra-articular autologous protein solution (APS) for the treatment of osteoarthritis in horses. Animals-40 client-owned horses with naturally occuring osteoarthritis. Methods: APS was generated from a dual-device system that concentrated plasma and WBC proteins and enriched platelet growth factors. Horses were randomly assigned to receive an intra-articular injection of 5 mL of saline (0.9% NaCl) solution (n = 20) or APS (20), exercised on a treadmill, and evaluated on the basis of lameness grades, kinetic gait analysis, joint circumference, and range of motion for 14 days. Horses...
Characteristics of respiratory tract disease in horses inoculated with equine rhinitis A virus. To develop a method for experimental induction of equine rhinitis A virus (ERAV) infection in equids and to determine the clinical characteristics of such infection. Methods: 8 ponies (age, 8 to 12 months) seronegative for antibodies against ERAV. PROCEDURES-Nebulization was used to administer ERAV (strain ERAV/ON/05; n = 4 ponies) or cell culture medium (control ponies; 4) into airways of ponies; 4 previously ERAV-inoculated ponies were reinoculated 1 year later. Physical examinations and pulmonary function testing were performed at various times for 21 days after ERAV or mock inoculation. Va...
Effects of interleukin-6 and interleukin-1β on expression of growth differentiation factor-5 and Wnt signaling pathway genes in equine chondrocytes. To determine the effects of interleukin (IL)-6 and IL-1β stimulation on expression of growth differentiation factor (GDF)-5 and Wnt signaling pathway genes in equine chondrocytes. Methods: Macroscopically normal articular cartilage samples from 6 horses and osteochondral fragments (OCFs) from 3 horses. Methods: Chondrocyte pellets were prepared and cultured without stimulation or following stimulation with IL-6 or IL-1β for 1, 2, 12, and 48 hours; expression of GDF-5 was determined with a quantitative real-time PCR assay. Expression of genes in various signaling pathways was determined with ...
Comparison between palpation and ultrasonography for evaluation of experimentally induced effusion in the distal interphalangeal joint of horses. To ultrasonographically quantify experimentally induced effusion of the distal interphalangeal (DIP) joint of horses and compare results with those obtained with palpation. Methods: 8 forelimbs from equine cadavers and forelimbs of 5 mares. Methods: Preliminary ex vivo experiments were performed to validate the methods. Then, the DIP joints of the forelimbs of standing horses were serially distended with saline (0.9% NaCl) solution (1, 4, and 10 mL) by injection through an intra-articular catheter. Two ultrasonographers measured distension of the dorsal recess of the DIP joint, and 2 surgeons,...
Effect of anesthetizing individual compartments of the stifle joint in horses with experimentally induced stifle joint lameness. To evaluate the effects of sequential anesthesia of the individual compartments of the equine stifle joint on lameness induced by intra-articular deposition of interleukin (IL)-1β. Methods: 6 horses. Methods: For each horse, baseline hind limb lameness was first evaluated. A randomly selected compartment of 1 stifle joint was then injected with IL-1β to induce synovitis and lameness; subsequently, the same compartment was anesthetized with 2% mepivacaine hydrochloride, and lameness was reevaluated. Two weeks later, baseline lameness was evaluated, and lameness was similarly induced; thereaft...
Microvasculature of the suspensory ligament of the forelimb of horses. To determine the microvascular anatomy of the suspensory ligament of the forelimb of horses. Methods: 17 cadaveric forelimbs from 9 adult horses with no known history of forelimb lameness. Methods: The median artery of the forelimb was cannulated proximal to the antebrachiocarpal joint and injected with contrast medium for CT evaluation of the gross vasculature (n = 2) or India ink to evaluate the microvasculature (12). Routine histologic evaluation was performed on an additional 3 forelimbs to confirm the microvascular anatomy. Results: The vascular supply of the suspensory ligament of the fo...
Short-term effect of ovariectomy on measures of insulin sensitivity and response to dexamethasone administration in horses. To evaluate the effect of ovariectomy on insulin sensitivity in horses and determine whether the effects of suppression of the hypothalamo-pituitary-adrenal axis differ before and after ovariectomy. Methods: 6 healthy mares. Methods: The horses underwent an IV glucose tolerance test (IVGTT), an insulin sensitivity test, and a dexamethasone suppression test before and 5 weeks after ovariectomy. Body weight, serum cortisol and plasma ACTH concentrations, serum insulin-to-blood glucose concentration ratios, and changes in blood glucose concentration with time after injection of glucose or insulin...
Effects of advanced age on whole-body protein synthesis and skeletal muscle mechanistic target of rapamycin signaling in horses. To determine the effects of advanced age on whole-body protein synthesis and activation of the mechanistic target of rapamycin (mTOR) signaling pathway in skeletal muscle of horses. Methods: Six 22- to 26-year-old (aged) and six 7- to 14-year-old (mature) horses. Methods: Whole-body protein synthesis was measured with a 2-hour primed constant infusion of (13)C sodium bicarbonate, followed by a 4-hour primed constant infusion of 1-(13)C phenylalanine. After the infusions, a biopsy specimen was obtained from a gluteus medius muscle and activation of protein kinase B (Akt), p70 riboprotein S6 kin...
Evaluation of the use of atropine sulfate, a combination of butylscopolammonium bromide and metamizole sodium, and flunixin meglumine to ameliorate clinical adverse effects of imidocarb dipropionate in horses. To evaluate the ability of atropine sulfate, butylscopolammonium bromide combined with metamizole sodium, and flunixin meglumine to ameliorate the clinical adverse effects of imidocarb dipropionate in horses. Methods: 28 horses with piroplasmosis. Methods: 28 horses were randomly assigned to 4 equal groups according to the pretreatment administered. Fifteen minutes before administration of 2.4 mg of imidocarb dipropionate/kg IM, horses in the first group were pretreated with 0.02 mg of atropine sulfate/kg IV, the second group with a combination of 0.2 mg of butylscopolammonium bromide/kg IV an...
Localization of the cutaneus trunci muscle reflex in horses. To determine the magnitude and location of skin movement attributable to the cutaneus trunci muscle reflex in response to localized stimulation of the skin of the dorsolateral aspect of the thoracic wall in horses. Methods: 8 horses. Methods: A grid of 56 reflective markers was applied to the lateral aspect of the body wall of each horse; markers were placed at 10-cm intervals in 7 rows and 8 columns. A motion analysis system with 10 infrared cameras was used to track movements of the markers in response to tactile stimulation of the dorsolateral aspect of the thoracic wall at the levels of T6...
Effect of large colon ischemia and reperfusion on concentrations of calprotectin and other clinicopathologic variables in jugular and colonic venous blood in horses. To determine the effect of large colon ischemia and reperfusion on concentrations of the inflammatory neutrophilic protein calprotectin and other clinicopathologic variables in jugular and colonic venous blood in horses. Methods: 6 healthy horses. Methods: Horses were anesthetized, and ischemia was induced for 1 hour followed by 4 hours of reperfusion in a segment of the pelvic flexure of the large colon. Blood samples were obtained before anesthesia, before induction of ischemia, 1 hour after the start of ischemia, and 1, 2, and 4 hours after the start of reperfusion from jugular veins and ve...
Pharmacokinetics and safety of silibinin in horses. To determine the oral bioavailability, single and multidose pharmacokinetics, and safety of silibinin, a milk thistle derivative, in healthy horses. Methods: 9 healthy horses. Methods: Horses were initially administered silibinin IV and silibinin phospholipid orally in feed and via nasogastric tube. Five horses then consumed increasing orally administered doses of silibinin phospholipid during 4 nonconsecutive weeks (0 mg/kg, 6.5 mg/kg, 13 mg/kg, and 26 mg/kg of body weight, twice daily for 7 days each week). Results: Bioavailability of orally administered silibinin phospholipid was 0.6% PO in...
Evaluation of antioxidant capacity and inflammatory cytokine gene expression in horses fed silibinin complexed with phospholipid. To evaluate antioxidant capacity and inflammatory cytokine gene expression in horses fed silibinin complexed with phospholipid. Methods: 5 healthy horses. Methods: Horses consumed increasing orally administered doses of silibinin phospholipid during 4 nonconsecutive weeks (0 mg/kg, 6.5 mg/kg, 13 mg/kg, and 26 mg/kg of body weight, twice daily for 7 days each week). Dose-related changes in plasma antioxidant capacity, peripheral blood cell glutathione concentration and antioxidant enzyme activities, and blood cytokine gene expression were evaluated. Results: Plasma antioxidant capacity increase...
Qualitative and quantitative interpretation of computed tomography of the lungs in healthy neonatal foals. To qualitatively describe lung CT images obtained from sedated healthy equine neonates (≤ 14 days of age), use quantitative analysis of CT images to characterize attenuation and distribution of gas and tissue volumes within the lungs, and identify differences between lung characteristics of foals ≤ 7 days of age and foals > 7 days of age. Methods: 10 Standardbred foals between 2.5 and 13 days of age. Methods: Foals were sedated with butorphanol, midazolam, and propofol and positioned in sternal recumbency for thoracic CT. Image analysis software was used to exclude lung from nonlung str...
Effects of exercise on markers of venous remodeling in lungs of horses. To determine the effects of 2 weeks of intense exercise on expression of markers of pulmonary venous remodeling in the caudodorsal and cranioventral regions of the lungs of horses. Methods: 6 horses. Methods: Tissue samples of the caudodorsal and cranioventral regions of lungs were obtained before and after conditioning and 2 weeks of intense exercise. Pulmonary veins were isolated, and a quantitative real-time PCR assay was used to determine mRNA expression of matrix metalloproteinase-2 and -9, tissue inhibitor of metalloproteinase-1 and -2, collagen type I, tenascin-C, endothelin-1, platelet...
Effect of forelimb lameness on hoof kinematics of horses at a walk. To determine kinematic changes to the hoof of horses at a walk after induction of unilateral, weight-bearing forelimb lameness and to determine whether hoof kinematics return to prelameness (baseline) values after perineural anesthesia. Methods: 6 clinically normal Quarter Horses. Methods: For each horse, a sole-pressure model was used to induce 3 grades of lameness in the right forelimb, after which perineural anesthesia was administered to eliminate lameness. Optical kinematics were obtained for both forelimbs with the horse walking before (baseline) and after induction of each grade of lame...
Effects of clopidogrel on the platelet activation response in horses. To evaluate the platelet activation response before and after treatment with clopidogrel in horses. Methods: 12 healthy adult mares. Methods: In a masked study, horses (6/group) were randomly allocated to alternately receive placebo or clopidogrel via nasogastric tube at a loading dose of 4 mg/kg followed by 2 mg/kg every 24 hours. Blood samples were collected before and 72 hours after initiation of treatment for ADP- and collagen-induced light transmission aggregometry; determination of closure time in collagen-ADP cartridges; modified thrombelastography for comparison of maximal amplitudes g...
Effect of forelimb lameness on hoof kinematics of horses at a trot. To determine kinematic changes to the hoof of horses at a trot after induction of unilateral, weight-bearing forelimb lameness and to determine whether hoof kinematics return to prelameness values after perineural anesthesia. Methods: 6 clinically normal Quarter Horses. Methods: For each horse, a sole-pressure model was used to induce 3 grades (grades 1, 2, and 3) of lameness in the right forelimb, after which perineural anesthesia was administered to alleviate lameness. Optical kinematics were obtained for both forelimbs with the horse trotting before (baseline) and after induction of each gr...
Comparison of two analyzers for measurement of plasma total carbon dioxide concentration in horses. To determine the degree of agreement between 2 analyzers for measurement of total CO₂ concentration (ctCO₂) in equine plasma. Methods: 6 healthy untrained horses, 6 trained Standardbreds undergoing a simulated race protocol, and 135 trained Standardbreds at a racetrack. Methods: Jugular venous blood samples were obtained from all horses. Two analyzers (commonly used analyzer A and less expensive analyzer B) were used to measure plasma ctCO₂ in each sample. Validation of both analyzers was conducted in accordance with guidelines established by the Clinical and Laboratory Standards Institu...
Effects of ketamine, propofol, or thiopental administration on intraocular pressure and qualities of induction of and recovery from anesthesia in horses. To assess the effects of ketamine hydrochloride, propofol, or compounded thiopental sodium administration on intraocular pressure (IOP) and qualities of induction of and recovery from anesthesia in horses. Methods: 6 healthy adult horses. Methods: Horses were sedated with xylazine hydrochloride (0.5 mg/kg), and anesthesia was induced with guaifenesin followed by ketamine (2 mg/kg), propofol (3 mg/kg), or thiopental (4 mg/kg) in a crossover study with ≥ 1 week between treatments. For each horse, IOP in the right eye was measured with a handheld applanation tonometer before and after xylazine ...
In vivo and in vitro evaluation of the effects of domperidone on the gastrointestinal tract of healthy horses. To determine the effects of domperidone on in vivo and in vitro measures of gastrointestinal tract motility and contractility in healthy horses. Methods: 18 adult horses and tissue samples from an additional 26 adult horses. Methods: Domperidone or placebo paste was administered to healthy horses in a 2-period crossover study. Gastric emptying was evaluated after oral administration of domperidone paste (1.1 or 5.0 mg/kg) or placebo paste by means of the acetaminophen absorption test in 12 horses. Frequency of defecation, weight of feces produced, fecal moisture, and stomach-to-anus transit ti...
Effect of underwater treadmill exercise on postural sway in horses with experimentally induced carpal joint osteoarthritis. To evaluate the effect of underwater treadmill exercise on static postural sway in horses with experimentally induced carpal joint osteoarthritis under various stance conditions. Methods: 16 horses. Methods: On day 0, osteoarthritis was induced arthroscopically in 1 randomly selected middle carpal joint of each horse. Beginning on day 15, horses were assigned to either underwater or overground (without water) treadmill exercise at the same speed, frequency, and duration. Two serial force platforms were used to collect postural sway data from each horse on study days -7, 14, 42, and 70. Horses ...
Pharmacokinetics of single-dose intragastric and intravenous pregabalin administration in clinically normal horses. To assess pharmacokinetics of pregabalin in horses after a single intragastric or IV dose. Methods: 5 healthy adult mares. Methods: Horses received 1 dose of pregabalin (approx 4 mg/kg) via nasogastric tube in a crossover-design study; after a 3-week washout period, the same dose was administered IV. Food was not withheld. Plasma pregabalin concentrations in samples obtained 0 to 36 hours after administration were measured by use of ultra-performance liquid chromatography with triple quadrupole tandem mass spectrometry. Pharmacokinetic variables were estimated by means of noncompartmental anal...
Evaluation of neutrophil apoptosis in horses with acute abdominal disease. To quantify peripheral blood neutrophil apoptosis in equine patients with acute abdominal disease (ie, colic) caused by strangulating or nonstrangulating intestinal lesions and compare these values with values for horses undergoing elective arthroscopic surgery. Methods: 20 client-owned adult horses. Methods: Peripheral blood was collected from horses immediately prior to and 24 hours after surgery for treatment of colic (n = 10) or elective arthroscopic surgery (10), and neutrophils were counted. Following isolation by means of a bilayer colloidal silica particle gradient and culture for 24 h...
Evaluation of the effects of age and pituitary pars intermedia dysfunction on corneal sensitivity in horses. To determine effects of age and pituitary pars intermedia dysfunction (PPID) on corneal sensitivity in horses. Methods: 20 adult horses allocated into 3 groups (PPID group, old [> 15 years old] horses with PPID [n = 5]; old group, old [> 15 years old] horses without PPID [9]; and young group, young [≤ 10 years old] horses without PPID [6]). All horses with PPID had hirsutism and abnormal fat deposition or laminitis; none of the old or young horses had hirsutism, abnormal fat deposition, or laminitis. Methods: A Cochet-Bonnet aesthesiometer was used to measure the corneal touch threshold (CTT...
Effects of intravenous lipopolysaccharide infusion on glucose and insulin dynamics in horses with equine metabolic syndrome. To test the hypothesis that glucose and insulin dynamics during endotoxemia differ between healthy horses and horses with equine metabolic syndrome (EMS). Methods: 6 healthy adult mares and 6 horses with EMS. Methods: Each horse randomly received an IV infusion of lipopolysaccharide (20 ng/kg [in 60 mL of sterile saline {0.9% NaCl} solution]) or saline solution, followed by the other treatment after a 7-day washout period. Baseline insulin-modified frequently sampled IV glucose tolerance tests were performed 27 hours before and then repeated at 0.5 and 21 hours after infusion. Results were ass...
Effects of equine metabolic syndrome on inflammatory responses of horses to intravenous lipopolysaccharide infusion. To test the hypothesis that inflammatory responses to endotoxemia differ between healthy horses and horses with equine metabolic syndrome (EMS). Animals-6 healthy horses and 6 horses with EMS. Methods: Each horse randomly received an IV infusion of lipopolysaccharide (20 ng/kg [in 60 mL of sterile saline {0.9% NaCl} solution]) or saline solution, followed by the other treatment after a 7-day washout period. Baseline data were obtained 30 minutes before each infusion. After infusion, a physical examination was performed hourly for 9 hours and at 15 and 21 hours; a whole blood sample was collect...
Accelerometric comparison of the locomotor pattern of horses sedated with xylazine hydrochloride, detomidine hydrochloride, or romifidine hydrochloride. To evaluate the duration of effects on movement patterns of horses after sedation with equipotent doses of xylazine hydrochloride, detomidine hydrochloride, or romifidine hydrochloride and determine whether accelerometry can be used to quantify differences among drug treatments. Methods: 6 healthy horses. Methods: Each horse was injected IV with saline (0.9% NaCl) solution (10 mL), xylazine diluted in saline solution (0.5 mg/kg), detomidine diluted in saline solution (0.01 mg/kg), or romifidine diluted in saline solution (0.04 mg/kg) in random order. A triaxial accelerometric device was used f...
Performance of a gravitational marrow separator, multidirectional bone marrow aspiration needle, and repeated bone marrow collections on the production of concentrated bone marrow and separation of mesenchymal stem cells in horses. Objective-To determine the efficiency of a novel point-of-care gravitational marrow separator and bone marrow aspiration needle for concentrated bone marrow production and bone marrow-derived mesenchymal stem cell (MSC) separation and assess the effect of repeated bone marrow collections in horses. Animals-8 healthy adult horses. Procedures-Bone marrow aspiration was performed twice (1 month apart) from sternebral bodies with a standard or prototype multidirectional needle. Concentrated bone marrow was obtained by gravitational marrow separation and evaluated for WBC and platelet counts, autom...
Effect of gluteus medius muscle sample collection depth on postprandial mammalian target of rapamycin signaling in mature Thoroughbred mares. To determine the effect of biopsy collection depth on the postprandial activation of mammalian target of rapamycin (mTOR) signaling factors, particularly protein kinase B, ribosomal protein S6 kinase, ribosomal protein S6, and eukaryotic initiation factor 4E binding protein 1 in middle-aged horses. Methods: 6 healthy Thoroughbred mares (mean ± SD age, 13.4 ± 3.4 years). Methods: Horses were fed a high-protein feed at 3 g/kg. Sixty minutes after horses were fed, the percutaneous needle biopsy technique was used to collect biopsy specimens from the gluteus medius muscle at 6, 8, and 10 cm belo...