In vivo studies involving horses refer to research conducted within living organisms to understand various biological processes, disease mechanisms, and therapeutic interventions in equine species. These studies provide insights into the physiological and pathological responses of horses under natural conditions. In vivo research encompasses a range of investigations, including pharmacokinetics, disease modeling, and the evaluation of treatment efficacy. It often involves the use of controlled environments to simulate real-life scenarios while observing the effects of specific variables on equine health. This page gathers peer-reviewed research articles and scholarly studies that explore the methodologies, findings, and implications of in vivo research in horses, contributing to the advancement of equine science and veterinary medicine.
Acland HM, Allen PZ, Kenney RM.After contagious equine metritis bacteria were inoculated into the uterus of mares, genital tract tissues were examined for presence of the organism by bacteriologic cultural technique and an indirect immunofluorescent staining technique. Up to 14 days after mares were inoculated, the organism was frequently in the lumen of the uterus and in the cervix and, less frequently, in the vagina, vestibule, clitoral fossa, clitoral sinus, and uterine tubes. After 21 to 116 days, the organism was occasionally found on the ovarian surface, in the uterine tubes, uterus, cervix, and vagina and more freque...
Johnson JA, Prescott JF, Markham RJ.The intragastric inoculation of a suspension of Corynebacterium equi on five consecutive days induced severe ulcerative colitis, typhlitis, and lymphadenitis of colonic and cecal nodes in two ponies necropsied three weeks after infection. No gross lesions were observed in two ponies necropsied ten days after infection. A single inoculum of equivalent size failed to induce gross lesions in four ponies killed at ten or 20 days after infection. Microscopic lesions consistent with early C. equi infection of Peyer's patches were seen in two of the ponies killed ten days after infection. Only one sm...
Roberts MC, Seawright AA.Colic was induced in horses and ponies following topical or intravenous (iv) administration of amitraz, a formamidine acaricide. The condition was characterised by rapid cessation of intestinal sounds, stasis, extensive impaction and tympany throughout the large colon. Three animals that were necropsied had a faecalith obstructing the proximal small colon aboral to marked colonic impaction. A reproducible and reversible impaction colic syndrome could be induced by an iv injection of 1 mg amitraz/kg body weight in solvent. There were immediate central nervous system and intestinal signs. Large ...
Nelson R, Hampe DW.Tracheal mucous transport rates were measured in 12 nonanesthetized horses after an intratracheal injection of 99mtechnetium-sulfur colloid. The transport rate of the subsequent bolus of radioactivity was determined, using a portable scaler rate meter fitted with a high-energy gamma-scintillation probe. A gamma-scintillation camera was used to verify bolus form and movement in 1 horse. The mean tracheal mucous transport rate was 1.66 +/- 0.24 cm/min.
Dyer RM, Leid RW.Isolated equine alveolar macrophages obtained by bronchopulmonary lavage of four live ponies demonstrated surface receptors for equine IgG, equine IgM, and complement-coated sheep red blood cells, but not equine IgM or complement-coated erythrocytes alone. In addition, demonstration of IgG receptors was found to depend on the level of erythrocyte sensitization and could not be demonstrated by red blood cell rosetting techniques at low levels of sensitization. Demonstration of receptors for equine complement by red cell rosetting techniques required the presence of both IgM antibody and serum d...
DiPietro JA, Paul A, Todd KS.Forty horses from a herd known to have benzimidazole-resistant small strongyles were treated with mebendazole (8.8 mg/kg) or combinations of mebendazole and piperazine monohydrochloride (25, 40, or 55 mg of piperazine base/kg). Pretreatment and 7-day posttreatment fecal examinations were done. Fecal cultures and strongyle egg per gram (epg) counts, and in vitro testing for benzimidazole resistance were performed. Results of fecal examinations prior to treatment were similar in all horses, and results of testing were positive for benzimidazole resistance. Horses treated with mebendazole and pip...
Donné-Op den Kelder GM, de Haas GH, Egmond MR.At alkaline pH porcine pancreatic phospholipase A2 is known to bind two Ca2+ ions per protein molecule. One Ca2+ ion is strongly bound to the active site and is essential for enzyme activity. A second Ca2+ ion binds more weakly to the protein and improves the affinity of the enzyme for lipid-water interfaces severalfold at high pH values. A group having a pK around 6 controls enzyme binding to lipid-water interfaces in the absence of Ca2+. By use of proton titration techniques this group is now identified to be a carboxylate having an abnormally high pK. Its pK shifts to a value around 4.5 in ...
Davies JV, Gerring EL.The effect of acepromazine, Buscopan (Crown Chemicals), pethidine and methadone was evaluated in ponies prepared with Thiry-Vella (T-V) loops. Motility was assessed by electrophysiological means (bipolar electrodes and strain gauge transducers) and by the passage through the T-V loop of a fluid test meal. Results were obtained from 26 experiments in three ponies and compared with six control experiments, in which saline had been administered to the same ponies. Each pony acted as its own control in each experiment and pre and post treatment values for slow wave frequency, spiking activity, del...
Brown MP, Pool RR.Braided carbon fiber sutures were used to repair surgically transected or lacerated digital flexor tendons of 20 mature horses (10 experimental and 10 clinical cases). In addition, 4 experimental horses had tenectomies that were not surgically repaired; these served as controls for the horses with carbon-implanted tendons. Six of the 10 clinically affected horses were returned to their intended use; 2 were euthanatized because of complications and 2 were still recuperating. The experimental horses were euthanatized at 12 days and 1, 2, 4, 8, and 12 months. Tendon scars were structurally and fu...
Davies JV, Gerring EL.Motility patterns in the equine small intestine were investigated in eight ponies. Muscular activity was assessed by means of extramural strain gauge transducers, bi-polar electrodes and in three of the animals, fitted with Thiry-Vella loops, the transit of fluid. Circular muscle contractions were preceded by spiking superimposed on the slow wave and fluid transit in the loops correlated with both these events.
Klei TR, Chapman MR, Torbert BJ, McClure JR.An indirect fluorescent antibody assay (IFA) was developed using Strongylus vulgaris third stage larvae (L3) as antigens. Observations using the IFA indicate that a species-specific antibody response to S. vulgaris L3 develops in S. vulgaris-infected ponies and that some surface L3 antigens are shared by adult worms. Sequential antibody levels against S. vulgaris were measured in strongyle-naive and in immune ponies following initial and challenge infections using the IFA and an indirect hemagglutination assay (IHA). Antibody levels measured by IFA increased faster following initial infections...
Mishra PC, Leach DH.The extrinsic and intrinsic venous drainage of the equine hoof have previously been poorly described. There is also an absence of information about the venous organisation of both primary and secondary dermal lamellae of the hoof wall. The purpose of this study was to describe the normal venous pattern of the horse hoof, especially that associated with the dermal lamellae of the wall. The venous organisation of 46 pairs of hooves from clinically healthy horses was studied using standard plastic vascular corrosion casts and histological sections. A consistent pattern of venous organisation was ...
Allen GP, Yeargan MR, Bryans JT.The effect of in vitro and in vivo serial virus passage on the genetic stability of equine herpesvirus 1 (EHV-1) was investigated by restriction endonuclease analysis of the viral DNA. DNAs of EHV-1 isolates at different passage levels in cultured cells or in Syrian hamsters were compared by electrophoresis of the DNA cleavage fragments produced by restriction endonuclease digestion. No changes were observed in the restriction profile of the DNAs of EHV-1 strains after 100 sequential passages in cultured equine cells. However, serial passage of the virus in hamsters or in cells of non-equine o...
Thomson JR, McPherson EA, Lawson GH, Wooding P, Brown R.The chymotrypsin activity of seven batches of Micropolyspora faeni and of five batches of Aspergillus fumigatus culture extracts, prepared for inhalation challenge in horses, was assayed and was found to range between 0.29 and 1.45 units/mg protein and 0.02 and 0.20 units/mg protein respectively. Horses affected with chronic obstructive pulmonary disease (COPD) were challenged with two batches of each antigen which had different chymotrypsin activities and no significant correlations were found between the degree of response to challenge and the chymotrypsin activity of the antigens. Inhalatio...
Ginther OJ.Fixation and orientation of the conceptus within the uterine lumen of 40 barren mares were examined by ultrasound daily on days 11-21 and at three-day intervals thereafter until day 48. The growth curve of the in situ conceptus had a distinct plateau between days 17-24, as determined by measurements of the width and area of conceptuses on the ultrasound images. The vesicle expanded at an average daily rate of 3-4 mm before the plateau and 2-3 mm after the plateau. Dramatic changes occurred in the shape of conceptus. The predominant shapes were approximately as follows: days 11-16, spherical; d...
Nara PL, Krakowka S, Powers TE, Garg RC.Fourteen young outbred horses, divided into 2 groups on the basis of 18- or 24-hour skin-test reactions to Streptococcus equi, were inoculated nasopharyngeally with virulent S equi. Animals (n = 6, group I) with evidence of previous exposure to S equi (positive dermal response and existing serum antibodies), with one exception, developed minimal or no signs of disease after inoculation. In contrast, S equi skin-test negative and seronegative horses (n = 8, group II) developed predictable and severe clinical signs of infection after their inoculation, including shedding of the organism from nas...
Cho SN, Collins MT, Reif JS, McChesney AE.Attempts to infect horses with Legionella pneumophila were undertaken to determine pathogenicity and to evaluate the possibility that horses serve as a reservoir for the organism. A previous study showed that the prevalence of antibodies to L pneumophila in the equine population exceeded 30% of over 600 sera examined. Horses were infected experimentally with the Philadelphia 1 or Bloomington 2 strain of L pneumophila IV or by aerosolization. Signs of clinical illness were restricted to a transient febrile response. A transient decrease in circulating lymphocytes occurred 2 days after inoculati...
Morris DD, Garcia M.Adult horses showed a mild diurnal variation in equine plasma thyroxine (T4) concentrations, but not triiodothyronine (T3). Plasma T4 concentrations tended to be higher between 5 PM and 8 PM than at 8 AM. Increases in plasma T4 and T3 were similar in adult healthy horses given 5, 10, or 20 IU of thyroid-stimulating hormone (TSH). The T4 peaked at approximately twice (2.0 +/- 0.4 times) as high as the base line at 6 to 12 hours after the TSH was given. The greatest change from base line T3 occurred at 1 to 3 hours after the TSH was given, but the magnitude of increase was widely variable (4.36 ...
Igwe OJ, Blake JW.The disposition kinetics of pemoline after iv and oral administration of 2.4 mg/kg of the drug were studied. The elimination half-life was 39.4 hr. The mean volume of distribution was 1.5 liters/kg indicating extensive tissue distribution and sequestration for an amphoteric drug. Plasma protein binding determined by in vitro equilibrium dialysis was concentration dependent. The mean binding capacity was found to be 0.80 mu-mol/g, an apparent dissociation constant of 3.73 X 10(-5) molar, and a total plasma protein concentration of 64.7 g/liter. The mean systemic availability by oral administrat...
Rose RJ, Hodgson DR, Leadon DP, Rossdale PD.The effect of intranasal administration of oxygen at a flow rate of 10 litres per minute for 10 minutes, was studied in a total of 19 foals (thoroughbred and pony) aged between 0.5 and 12 hours. Arterial blood samples were collected before and after oxygen administration for the determination of paO2, paCO2, pHa and base excess. The foals were divided into three groups: five spontaneously delivered thoroughbred and pony foals (group 1), seven term induced thoroughbred foals (group 2) and seven induced premature pony foals (group 3). To examine the effect of duration of oxygen administration on...
Seide RK, Kehoe JM.Studies of the molecular biology of lymphoid cells have markedly increased our understanding of how millions of different antibodies can be synthesized by a single animal. To date, the most detailed understanding has been achieved for the mouse, primarily because of the relatively greater experimental availability of this species. These studies, as well as those involving other species, have shown that the complete genes for antibody polypeptide chains are assembled from disparate genetic elements which are originally widely separated in the genome. The assembly process itself, together with t...
Bonagura JD, Pipers FS.Contrast M-mode echocardiography was utilized to study animals with congenital and acquired cardiac defects. Contrast was produced through the rapid injection of isotonic NaCl solution, the patient's blood, or indocyanine green dye into the circulation. Peripheral vein and intracardiac injections of contrast material were used to document ventricular septal defect, tetralogy of Fallot, atrial septal defect, and mitral valve regurgitation. The technique was safe and useful for both small and large animals.
Ralston SL, Baile CA.This series of experiments was designed to investigate gastrointestinal (GI) stimuli that contribute to the normal control of feed intake in ponies. Osmotic stimuli were tested using intragastric (IG) infusion of .83 osmolar solutions of xylose (250 g) and NaCl (48 g) vs 2-liter water controls. Treatments were given 15 min before ponies were allowed ad libitum access to pelleted feed after a 4-h fast. Both hyperosmotic solutions delayed onset of the first meal (xylose: 72 ± 32 min, P<.05; NaCl: 71 ± 40 min, P<.1), resulting in an immediate reduction (P<.01) in feed intake. No effects were ob...
Threlfall WR, Keefe TJ.Serum levels of ticarcillin disodium, a semi-synthetic penicillin (Beecham Laboratories, Bristol, Tennessee, 37620), were measured at various time intervals up to and including 24 h after intrauterine and intramuscular administration in adult female horses. Three separate studies were conducted in Part I: in the first and second studies, serum levels were measured after intrauterine administration of 1 and 3 g of ticarcillin, respectively, and in the third study, levels were measured after intramuscular administration of 6 g of ticarcillin. In Part II, serum levels of ticarcillin were measured...
Nilsson O, Klingborn B.The effect of oxfendazole (Synanthic vet. Syntex) on the strongyle egg output of naturally infected horses was evaluated. It was demonstrated that the compound, administered orally as an 18,5% paste or as 6,48% pellets mixed in feed (46.3 grams per 300 kg bodyweight) at a dose-rate of 10 mg per kg bodyweight, markedly reduced the strongyle egg output over a 10 week period. As this period to egg reappearance is considerably longer than for most other anthelmintics at recommended dose levels, oxfendazole may be considered a valuable compound for the control of strongylosis in horses.
Simpson KS, Adams MH, Behrendt-Adam CY, Baker CB, McDowell KJ.Complex changes in gene expression must occur at the proper time and in the appropriate tissues for pregnancy to be successful. Therefore, research aimed at defining the regulation of gene expression in conceptuses is of critical importance. However, information on developmentally regulated changes in gene expression in horse conceptuses is sparse and inadequate. In the present study, suppression subtractive hybridization was used to identify genes that are expressed more highly at day 15 than on day 12 of gestation. This period encompasses maternal recognition of pregnancy and the beginning o...
Higgins AJ, Lees P, Taylor JB.In a two part cross-over experiment, acute inflammatory exudates were induced in 7 ponies by subcutaneous implantation of 3 sterile carrageenin-soaked polyester sponge strips. Treatment comprised a single therapeutic geenin-soaked polyester sponge strips. Treatment comprised a single therapeutic dose of 4.4 mg/kg phenylbutazone (PBZ) administered intravenously at the time of sponge implantation. Exudates were harvested at 6, 12 and 24 hours and examined for leukocyte and erythrocyte numbers using the improved Neubauer technique; for eicosanoids by radioimmunoassay and by high performance liqui...
Horohov DW, Keadle TL, Pourciau SS, Littlefield-Chabaud MA, Kamerling SG, Keowen ML, French DD, Melrose PA.Intense exercise affects various parameters of the immune system. The overall effect of exercise on immune function is dependent upon the physical condition of the subject, the intensity and duration of the exercise period, and the immune parameter assessed. Unconditioned horses subjected to a single bout of intensive exercise exhibit multiple alterations in immune function, including an augmentation of lymphokine activated killer (LAK) cell function. This increase in LAK cell activity is not due to an increase in circulating LAK precursors. While peripheral blood mononuclear cells from exerci...
Palozzo A, Celani G, Guerri G, Straticò P, Varasano V, Petrizzi L.Segmental posthetomy, also referred to as circumcision, reefing or posthioplasty, consists of removing a circumferential segment of the internal preputial lamina (internal preputial fold) followed by end-to-end anastomosis of skin edges. The purpose of this case series is to describe the successful outcome of segmental posthetomy for treating different diseases involving the internal or/and external preputial fold, while restoring the normal telescopic function. In this paper, we report the first case of complete degloving injury of the equine penis in the literature (case 1) and describe thre...
Ross KA, Kolb DS, Macedo A, Anderson M, Klein C.This study tested the hypothesis that the presence of prostaglandin E2 in seminal plasma would aid in the transport of phenolsulfonphthalein (PSP) across the uterotubal junction. Five mares in estrus were inseminated during estrus with PSP dissolved in phosphate-buffered saline and during the subsequent estrus with PSP added to a standard insemination dose. Serum and urine samples were obtained at hours 0, 1, 2, and 3 following treatment and examined for the presence of PSP. Phenolsulfonphthalein could not be detected in any of the urine samples collected from mares following either treatment....
Bracamonte JL, Duke-Novakovski T.This study evaluated the use of an articulating automated suturing device for laparoscopic closure of the nephrosplenic space in standing horses. Closure of the nephrosplenic space was performed in 4 horses using an automated suturing device. Second-look laparoscopy was performed at 5 weeks. A smooth fibrous adhesion formed between the spleen, the perirenal fascia, and the nephrosplenic ligament in 3 of the 4 horses in which the nephrosplenic space was closed using the automated suturing device. In 1 horse, closure of the nephrosplenic space was not possible due to constant breakage of the end...
Weatherall KM, Boone LH, Caldwell FJ, Cole RC, Cattley RC, Lascola KM, Clark-Price SC, Farag R, Perkins E, Hanson RR.To compare the biomechanical properties and healing of ventral midline celiotomies (VMC) closed with a self-locking knot combination and forwarder start and Aberdeen end (F-A) vs a traditional knot combination and surgeon's start and end (S-S). Methods: In vivo, experimental. Methods: Twenty-one horses. Methods: Fourteen horses underwent VMC, which was closed with either an F-A (n = 7) or an S-S (n = 7) knot combination. Incisions were subjectively graded by masked evaluators for dehiscence, edema, and drainage. Biomechanical testing was performed on three abdominal segments, and histology was...
Vernunft A, Löhrke B, Tuchscherer A, Weitzel JM, Viergutz T.Anti-Muellerian hormone (AMH) is synthesized only by granulosa cells in female mammals as an inhibiting factor for early follicular recruitment. Especially in preantral and small antral follicles, expression of AMH is very intensive. However, we hypothesize that AMH affects also the development of large follicles by an estrogenesis modification. This current investigation provides for the first time information about concentrations of AMH in equine follicular fluid and demonstrates their relationship to functional characteristics of follicle development. Therefore, fluids of follicles in diffe...
Hunyadi L, Papich MG, Pusterla N.The purpose of this study was to determine if a low dose of diclazuril (0.5mg/kg of 1.56% diclazuril pellets) given to six healthy adult horses every 3-4 days for a total of five administrations would achieve steady-state plasma concentrations known to be inhibitory to Sarcocystis neurona and Neospora caninum. Blood was collected via venipuncture immediately before (trough concentrations) and 10h after (peak concentrations) each diclazuril administration and analysed by high-pressure liquid chromatography. The mean population-derived peak concentration was 0.284μg/mL and the mean terminal hal...
Iqbal J, Edington N.Equid herpesvirus 1 (EHV-1) is the most common cause of virus-induced abortion in horses. After primary infection the virus becomes latent predominantly in the respiratory tract lymph nodes and the genome can also be detected in the peripheral nervous system. The role of mouse as a feasible model for the establishment of latency and reactivation of EHV-1 was investigated. Intracerebral and intranasal infections of 3- and 17-day-old mice were made and virus replication was confirmed by virus isolation and detected by indirect immunofluorescence (IIF) in brain. For reactivation studies, the mice...
Hendrix DV, Newkirk KM.To determine whether epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 2 (HER2) are expressed in periocular squamous cell carcinomas (SCCs) of horses. Methods: Biopsy specimens of SCCs from 46 horses. Methods: Pathology records were searched retrospectively for biopsy specimens of periocular SCCs obtained from horses. Slides of the specimens were reviewed histologically to confirm the SCC diagnosis and stained for EGFR and HER2 by immunohistochemical methods. For both EGFR and HER2, the immunohistochemical staining intensity and percentage of stain-positive cel...
Ludders JW, Palos HM, Erb HN, Lamb SV, Vincent SE, Gleed RD.To determine if horses before undergoing anesthesia for surgical correction of colic would have lower plasma arginine vasopressin (AVP) concentrations than healthy horses undergoing anesthesia for arthroscopic surgery, and would not increase their plasma AVP concentrations in response to anesthesia and surgery. Methods: Prospective clinical study. Methods: University teaching hospital. Methods: Fourteen horses with colic and 8 healthy horses. Methods: Horses with colic underwent anesthesia and surgery for alleviation of colic, and healthy horses underwent anesthesia and surgery for arthroscopy...
DiPietro JA, Lock TF, Todd KS, Davis JL.Eighteen pony foals inoculated with 1,500 +/- 109 infective Parascaris equorum eggs were given 0.02 ml of ivermectin vehicle (liquid)/kg of body weight, PO, (control); 0.2 mg of ivermectin paste/kg, PO; or 0.2 mg ivermectin liquid/kg, PO, on postinoculation day (PID) 28. Foals were euthanatized on PID 42, and the small intestinal contents were examined for P equorum larvae. The mean number of fourth-stage P equorum larvae in foals treated with ivermectin paste and liquid were 3.5 and 6, respectively. Significantly (P less than 0.01) higher mean numbers of larvae (1,250) were detected in foals ...
Vanderwall DK, Woods GL, Weber JA, Lichtenwalner AB.Transrectal ultrasonography was used to test the hypothesis that prostaglandin E(2) (PGE(2)) would increase the uterine transport of simulated embryonic vesicles in mares. Uterine transport of PGE(2)-releasing (PGE) vesicles, vehicle-releasing (sham) vesicles, and equine embryos was contrasted on Day 12 or Day 13 post ovulation. In Experiment 1, there was no difference (P>0.10) in transport of PGE vesicles, sham vesicles, Day-12 embryos, and Day-12 embryos after cervical manipulation (n = 3 per group). In Experiments 2 and 3, respectively, transport of PGE and sham vesicles was contrasted with...
Hefner EM, Lin HC, Cole RC, Moore PA, McMullen RJ.To compare image quality and acquisition time of corneal and retinal spectral domain optical coherence tomography (SD-OCT) under 3 different sedation-anesthesia conditions in horses. Methods: 6 middle-aged geldings free of ocular disease. Methods: 1 randomly selected eye of each horse was evaluated via SD-OCT under the following 3 conditions: standing sedation without retrobulbar anesthetic block (RB), standing sedation with RB, and general anesthesia with RB. Five regions of interest were evaluated in the cornea (axial and 12, 3, 6, and 9 o'clock positions) and fundus (optic nerve head). Thre...
Glaze MB, McGuire TC, Schmidt GM, Leid RW.A quantitative investigation of equine tear and aqueous humor immunoglobulins was done using normal horses and ponies as well as horses and ponies infected with Onchocerca cervicalis. The equine immunoglobulin isotypes IgGa, IgM, IgA and IgG(T) were quantitated by either single radial immunodiffusion (SRID) or radioimmunoassay (RIA). Tear immunoglobulin levels for IgGa (128 +/- 151 micrograms/ml), IgA (1,664 +/- 1,038 micrograms/ml) and IgM (106 +/- 74 micrograms/ml) were measured, while IgG(T) was not detectable. In horses with ocular inflammation the IgGa was 18-fold higher in the tears, 2,2...
Olive J, Lambert N, Bubeck KA, Beauchamp G, Laverty S.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,...
Winder NC, von Fellenberg R.In lungs from 22 horses, the number and type of mast cells in histologically normal specimens were compared with those in specimens with various histological lesions. Tissues fixed in Carnoy's solution were superior to those fixed in formalin for the identification of mast cells. Fixation of lung specimens from eight horses in Carnoy's solution and formalin allowed the identification of two subpopulations of mast cells: formalin-sensitive, which predominated and formalin-resistant. Specimens with mild chronic tracheitis and mild and moderate chronic bronchitis generally had slight increases in...
Vanderstraeten E, Bogaert L, Bravo IG, Martens A.Squamous cell carcinoma (SCC) represents the most common malignant tumour of the eye and external genitals in horses. Comparable to humans, papillomaviruses (PV) have been proposed as etiological agents of cancer in horses and recently, Equine papillomavirus type 2 (EcPV2) has been identified in genital SCCs. Hitherto it had never been demonstrated in ocular SCCs. The first goal of this study was to determine the prevalence of EcPV2 DNA in tissue samples from equine genital and ocular SCCs, genital papillomas and penile intraepithelial neoplasia (PIN) lesions, using EcPV2-specific PCR. The sec...
Suagee-Bedore JK, Hebrock S, Sundin O, Lengi AJ, Corl BA, Worth M.LinPro™ (LP) is a commercial dietary supplement marketed to increase hoof growth and quality. Ten mature (5-15 years) non-pregnant Quarter Horse mares without existing hoof quality issues were used to test the hypothesis that 32 weeks of daily supplementation with 113 g of LP would increase hoof growth rates as compared to non-supplemented controls. Hooves were trimmed at the start of the study and every 8 weeks thereafter. A mark was applied on the hoof wall surface at 2.5 cm below the junction of the hoof wall and coronary band. At each trimming, the distance between the mark and coronary ...
Williamson JA, Dascanio JJ, Christmann U, Johnson JW, Rohleder B, Titus L.Simulation in veterinary education offers a solution for bridging the gap between observation and performance of clinical skills. An equine neck model was created that allows repetitive practice of jugular phlebotomy, intramuscular (IM) injection, and intravenous catheterization. The aim of this study was to validate the model for jugular phlebotomy and IM injection. We surveyed experienced veterinarians on the model's realism and the comprehensiveness of its features. In a randomized experimental study, we compared the learning outcomes of first-year veterinary students trained on the model (...
Skov Hansen S, Tóth T.To report the frequency of radiocarpal joint (RCJ) perforation during two proximolateral carpal sheath (CS) approaches and to investigate whether the presence or absence of a natural communication between the RCJ and CS. Methods: Experimental, randomized, controlled study. Methods: Twelve adult horses and 12 cadaver front limbs. Methods: Proximolateral CS tenoscopy was performed on both carpi of 12 horses under general anaesthesia. Limbs were randomly assigned into two groups. In group 1, the instrument portal was centered at the level of the distal radial physeal remnant (PR). In group 2, the...
Moore AB, Roesel OF, Fessler JF, Bottoms GD.The value of naloxone (1 mg/kg of body weight/hr for 4 hrs), a beta-endorphin antagonist, was assessed in the management of endotoxin-induced shock in ponies. Three groups of 5 ponies each were used: controls, ponies given Escherichia coli endotoxin put untreated, and ponies given endotoxin and then treated with naloxone. Endotoxin-induced changes in hemodynamics, blood chemical values, regional blood flow, plasma enzymes, and energy supplies were measured at selected times during the first 6 hours after endotoxin was given. There was no evidence that beta-endorphins released during shock were...
Nishita T, Anezaki R, Matsunaga K, Orito K, Kasuya T, Sakanoue H, Matsunaga A, Arishima K.Although endoscopy is the definitive diagnostic method for the detection of colonic ulcers, the equipment required for performing the test is costly and difficult to use. Therefore, a simple cost-effective and reliable screening test for intestinal tract bleeding is needed. To this end, we measured carbonic anhydrase isozymes (CA-I and CA-II) originating from erythrocytes by ELISA in order to determine if they could be used as markers of occult blood in feces. For fecal extract preparation, 2 g of feces were mixed with 4 ml of 0.01 M Tris-HCl (pH 8.0) containing 0.01% thimerosal. The concentra...
Taniguchi K, Obitsu T, Ohmura H, Hiraga A, Hata H, Aida H, Akiyama K, Tanaka K.A rigid-type of polyethylene T-cannula was fitted into the anterior ileum of six horses in order to improve the cannulation techniques. A piece of polyethylene net was fastened onto the intestinal wall around the cannula to prevent dislodgment of the cannula by promoting a secure adhesion between the ileum and the abdominal wall. The cannula barrel sheathed with silicone tubing was exteriorized through a stab incision at the lateral ventral wall on the transverse line of the second lumber vertebra, and a flange was screwed onto the barrel. The feeding regime gradually increased concentrate wit...
Lean NE, Zedler ST, Van Eps AW, Engiles JB, Ford M, Stefanovski D, Walsh DM, Pollitt CC.Surgical stabilisation of the distal phalanx (DP) is a potential therapeutic strategy for severe acute laminitis. Objective: To evaluate the effects of locking compression plate (LCP) fixation of the DP to the dorsal hoof wall. Methods: Ex vivo and in vivo experiments. Methods: A T-shaped LCP was applied to one limb per pair in six pairs of cadaver forelimbs subjected to a combination of thermally induced lamellar failure and vertical load to simulate severe acute laminitis. Standard radiographic measurements were used to compare DP displacement. The LCP was then applied to one forefoot in 12 ...
Valpotić I, Kastelan M, Rudolf M, Gerencer M, Jukić B, Basić I.The percentage of T and B lymphocytes in the peripheral blood of horses chronically infected with equine infectious anaemia (EIA) virus was determined and the results were compared with the percentage of these cells in healthy uninfected horses. Cells with membrane receptors for sheep erythrocytes (T and active T lymphocytes) were determined by E and A rosette techniques, while cells with receptors for the C3b component of complement and those with receptors for mouse erythrocytes (B lymphocytes), were determined by the EAC rosette method. The percentage of Fe positive cells was assayed by the...
Zachar EK, Burgess HJ, Wobeser BK.Fine-needle aspiration (FNA) is commonly used to diagnose skin disease in companion animals, but its use in horses appears to be infrequent. Equine veterinarians in western Canada were surveyed to determine their opinions about FNA and 15 years of diagnostic submissions were used to compare the perceived to actual value of FNA in the diagnosis of skin disease in horses. Practitioners viewed FNA as quick, easy, economical, and minimally invasive. However, most veterinarians rarely chose to use FNA due to a perception that sample quality and diagnostic yield were poor and there was a narrow rang...
de Oliveira AC, Rosenbruch M, Schulz LC.The morphology of asteroid bodies in equine arteries is demonstrated by light microscopy as well as by scanning and transmission electron microscopy combined with chemical analysis. Asteroid bodies first occur in horses at four weeks of age in all investigated tissues except the esophagus and always are located in the subendothelial space. The number, shape, ultrastructure and chemical composition of asteroid bodies differ markedly--depending on the age of the horse. Asteroid bodies are round and smooth in foals, but are shaped irregularly and have several projections and marked stratified cal...
Herdan CL, Nicholson CL, Firth EC.The third carpal bone (C3) responds to exercise by adaptive modeling of bone and articular calcified cartilage along the dorsal load path. Canals penetrating articular calcified cartilage, thought to contain vascular tissue, are reported in numerous species. Their significance remains unclear. Our objective was to determine if the number of canals was significantly different in strenuously exercised and control young horses and in a site of intermittent high loading compared to sites sustaining lower habitual loads. Volumetric bone mineral density in the radial facet of C3 of strenuously exerc...
