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.
Brown MP, Trumble TN, Merritt KA.To investigate effects of osteochondral injury on high-mobility group box chromosomal protein 1 (HMGB-1) concentrations in synovial fluid (SF) from Thoroughbreds and to compare these results with radiographic and arthroscopic scores of severity of joint injury. Methods: 40 clinically normal rested Thoroughbreds (group 1) and 45 Thoroughbreds with osteochondral injury as a result of racing. Methods: SF was obtained from the metacarpophalangeal (MCP) joints, metatarsophalangeal (MTP) joints, middle carpal joints, and radiocarpal joints. For group 2, radiographic and arthroscopic scores were dete...
Ellison S, Witonsky S.Sarcocystis neurona is the principal etiologic agent of equine protozoal myeloencephalitis (EPM). An immunodominant protein of S. neurona, SnSAG-1, is expressed by the majority of S. neurona merozoites isolated from spinal tissues of horses diagnosed with EPM and may be a candidate for diagnostic tests and prophylaxis for EPM. Five horses were vaccinated with adjuvanted recombinant SnSAG1 (rSnSAG1) and 5 control (sham vaccinated) horses were vaccinated with adjuvant only. Serum was evaluated pre- and post-vaccination, prior to challenge, for antibodies against rSnSAG1 and inhibitory effects on...
Checura CM, Beg MA, Parrish JJ, Ginther OJ.The functional relationships among intrafollicular free insulin-like growth factor 1 (IGF1), circulatory gonadotropins, and development of the dominant follicle were studied in 40 mares in two experiments. A GnRH antagonist (Acyline) was given i.m. at the expected beginning of follicular deviation (largest follicle or F1> or =20mm; Day 0) alone (Acyline group) or in combination with intrafollicular treatment of F1 with rhIGF1 (Acyline/IGF1 group). In Experiment 1, blood samples, follicular-fluid samples, and diameter of F1 were taken on Days 1 and 2. In Experiment 2, daily follicular diamet...
Bell C, Tatarniuk D, Carmalt J.To describe and evaluate an endoscope-guided balloon sinuplasty technique for dilation of the equine nasomaxillary opening (NMO). Methods: Experimental study. Methods: Equine cadaver heads (n=5); Quarter Horses (n=4). Methods: A custom rigid balloon introducer was passed into position within the NMO at the caudal recess of the middle meatus. Under endoscopic guidance, a balloon catheter was passed via the introducer into the NMO and inflated to 6 atmospheres, for 30 seconds 3 times, to dilate the NMO. Drainage rates after sinuplasty were evaluated for the caudal maxillary sinus in 5 cadaver he...
Hellberg W, Mellor PS, Torsteinsdóttir S, Marti E.Insect bite hypersensitivity (IBH) is an IgE-mediated allergic dermatitis of horses caused by bites of insects such as Culicoides or Simulium spp. The aim of the present study was to compare the IgE-binding pattern of sera of IBH-affected horses to Culicoides nubeculosus and Simulium vittatum salivary gland extracts (SGE). Individual IgE responses to proteins of S. vittatum and C. nubeculosus SGEs were evaluated in 15 IBH-affected and three healthy horses on immunoblots. Fourteen out of the 15 IBH-affected but none of the healthy horses showed individual IgE binding patterns to seven and six m...
Delgado MA, Monreal L, Armengou L, Segura D, Ríos J.Peritoneal D-Dimer concentration can be determined to assess peritoneal fibrinolysis activity in horses with gastrointestinal disorders. However, blood contamination of peritoneal fluid may occur during collection and could alter peritoneal D-Dimer concentration. Objective: Blood contamination in peritoneal fluid does not affect interpretation of peritoneal D-Dimer concentration in horses with colic. Methods: Thirty-four horses with colic and 4 healthy horses. Methods: Peritoneal fluid and blood samples were simultaneously collected upon admission. Then, peritoneal fluid was serially contamina...
Mienaltowski MJ, Huang L, Frisbie DD, McIlwraith CW, Stromberg AJ, Bathke AC, Macleod JN.Full-thickness articular cartilage lesions that reach to the subchondral bone yet are restricted to the chondral compartment usually fill with a fibrocartilage-like repair tissue which is structurally and biomechanically compromised relative to normal articular cartilage. The objective of this study was to evaluate transcriptional differences between chondrocytes of normal articular cartilage and repair tissue cells four months post-microfracture. Methods: Bilateral one-cm2 full-thickness defects were made in the articular surface of both distal femurs of four adult horses followed by subchond...
Capucchio MT, Márquez M, Pregel P, Foradada L, Bravo M, Mattutino G, Torre C, Schiffer D, Catalano D, Valenza F, Guarda F, Pumarola M.Many age-related changes are described in the nervous system of different species, but detailed studies of brain lesions in ageing horses are lacking. The aim of the present study was to systematically characterize lesions in the brains of 60 horses aged from 7 to 23 years. No gross changes were present in any brain. Microscopically, spongiform changes, lipofuscin storage, corpora amylacea, gliosis and satellitosis were common, together with axonal and neuronal swellings. The most important findings were the presence of pseudocalcium-calcium (pCa-Ca) deposits and arterial wall degeneration. Sc...
Musilova P, Kubickova S, Horin P, Vodicka R, Rubes J.Cross-species chromosome painting has been applied to most of the species making up the numerically small family Equidae. However, comparative mapping data were still lacking in Asiatic asses kulan (Equus hemionus kulan) and kiang (E. kiang). The set of horse arm-specific probes generated by laser microdissection was hybridized onto kulan (E. hemionus kulan) and kiang (E. kiang) chromosomes in order to establish a genome-wide chromosomal correspondence between these Asiatic asses and the horse. Moreover, region-specific probes were generated to determine fusion configuration and orientation of...
Peretich AL, Abbott LL, Andrews FM, Dhar MS.To determine whether expression of mRNA for sodium-potassium adenosine-triphosphatase (NAKA) and sodium-hydrogen exchanger (NHE) in samples of the nonglandular portion of the equine gastric mucosa was altered by exposure to volatile fatty acids (VFAs) in an acidic environment. Methods: 10 horses (5 or = 12 years old). Methods: Samples of the nonglandular portion of the gastric mucosa were collected and exposed in Ussing chambers to Ringer's solution (control samples), Ringer's solution containing a mixture of VFAs (pH, 1.5 or 4.0), or Ringer's solution containing acetic acid (pH, 1.5 or 4.0)....
Lampe V, Dierks C, Distl O.Osteochondrosis (OC) is an inherited developmental disease in young horses most frequently observed in thoroughbreds, trotters, warmblood and coldblood horses. Quantitative trait loci (QTL) for equine OC have been identified in Hanoverian warmblood horses employing a whole genome scan with microsatellites. A QTL on ECA16 reached the genome-wide significance level for hock osteochondrosis dissecans (OCD). The aim of this study was to refine this QTL on ECA16 using an extended marker set of 34 newly developed microsatellites and 15 single nucleotide polymorphisms (SNPs). We used the same 14 pate...
Goehring LS, van Maanen C, Berendsen M, Cullinane A, de Groot RJ, Rottier PJ, Wesselingh JJ, Sloet van Oldruitenborgh-Oosterbaan MM.Equid herpesvirus type 1 (EHV-1)-associated myeloencephalopathy (EHM) may follow an infection with the virus in horses. This study tested three hypotheses: (1) a large inhaled dose of a neuropathogenic EHV-1 strain would induce a cell-associated viraemia in all infected horses; (2) neurological disease will only occur in viraemic horses, and (3) the cerebrospinal fluid (CSF) composition following EHV-1 viraemia will be an indicator for EHM. Four EHV-1 seronegative horses were inoculated with EHV-1 by inhalation. Three developed clinical signs of neurological disease, which were mild in two hor...
Bosch G, van Schie HT, de Groot MW, Cadby JA, van de Lest CH, Barneveld A, van Weeren PR.Tendon injuries are notorious for their slow and functionally inferior healing. Intratendinous application of platelet-rich plasma (PRP) has been reported to stimulate the repair process of tendon injuries, but there is little conclusive evidence for its effectiveness. A placebo-controlled experimental trial was performed to test the hypothesis that a single intratendinous PRP treatment enhances the quality of tendon repair, as evidenced by improved biochemical, biomechanical, and histological tissue properties. In six horses, tendon lesions were created surgically in the Superficial Digital F...
Skiöldebrand E, Ekman S, Heinegård D, Hultenby K.The present study was designed to delineate the presence of COMP at the ultrastructural level comparing concentrations between two areas of articular cartilage from the equine third carpal bone, subjected to different loading, from trained and untrained horses. We also analyzed the fibril thickness of collagen type II in the same compartments and zones. Samples were collected from high load-bearing areas of the dorsal radial facet (intermittent high load) and an area of the palmar condyle (low constant load) in five non-trained and three trained young racehorses. The data show that COMP is muc...
Fintl C, Pearson GT, Mayhew IG, Stewart Lowden C, Hopwood PA, Palgrave CJ, Proudman CJ, Barrie Edwards G, Taylor SE, Hudson NP.Previous immunohistochemical studies targeting the receptor tyrosine kinase (c-Kit) have demonstrated an apparent reduction in the number of gastrointestinal pacemaker cells--the interstitial cells of Cajal (ICC)--in horses with intestinal motility disorders. This study compared the level of transcription of the c-kit gene encoding this receptor in horses with and without such motility disorders. Transcription levels of this gene were also compared to the density of ICC immunohistochemically positive for the c-Kit antigen. Intestinal samples were collected from 18 horses with intestinal diseas...
DeRossi R, Coelho AC, Mello GS, Frazílio FO, Leal CR, Facco GG, Brum KB.To establish a low-cost method to prepare platelet-rich plasma (PRP) and evaluates the potential of platelet derived factors to enhance wound healing in the surgical wounds in equine. Methods: To obtain a PRP gel, calcium gluconate and autologous thrombin were added to platelet-rich plasma. For the tests six saddle horses were used and two surgical incisions were made in each animal. Wounds were treated with PRP gel or untreated. Sequential wound biopsies collected at Treatment 1: at days 5 and 30 and Treatment 2: at days 15 and 45 post wounding permitted comparison of differentiation markers ...
Zipplies JK, Hauck SM, Schoeffmann S, Amann B, van der Meijden CH, Stangassinger M, Ueffing M, Deeg CA.Equine recurrent uveitis (ERU) is an incurable disease affecting the inner eye that leads to blindness, through activated T cells that pass the blood-retinal barrier and destroy the retina. Serum markers are a desirable choice for monitoring development of disease, as serum is easy accessible and the markers could serve to predict the beginning of disease or an imminent relapse. Methods: In this study, serum proteomes (depleted of high-abundance serum proteins) of horses with ERU and healthy controls were compared with the 2-D DIGE (two-dimensional gel electrophoresis) technique to identify di...
Spizziri BE, Fox MH, Bruemmer JE, Squires EL, Graham JK.Irreversible damage occurs to spermatozoal membranes, during the phase transition, when spermatozoa are cooled from room temperature to 5 degrees C. Some of this damage can be ameliorated by adding cholesterol to the membrane, thereby altering membrane lipid composition. Adding cholesterol-loaded cyclodextrins (CLCs) to stallion spermatozoa prior to freezing, increases cell cryosurvival. However, the fertilizing potential of CLC-treated stallion spermatozoa is unknown. To address this, experiments were conducted which evaluated the ability of CLC-treated stallion spermatozoa to capacitate, acr...
Sessions DR, Vick MM, Fitzgerald BP.Matrix metalloproteinases (MMP) and tissue inhibitors of MMP (TIMP) regulate tissue remodeling events necessary for ovulation. Thus, changes in MMP and TIMP expression and protein enzyme activity were examined in vivo and in vitro during follicular development and atresia in the horse. Equine granulosa cells and follicular fluid from medium (15 to 29 mm) healthy and atretic follicles and from large (>30 mm) healthy and preovulatory follicles were collected by transvaginal aspiration. The cells were either snap-frozen (in vivo study) or cultured for 48 h (in vitro study) to determine gene ex...
Schmitz A, Theurillat R, Lassahn PG, Mevissen M, Thormann W.CE with multiple isomer sulfated-CD as selector was used for the simultaneous analysis of the stereoisomers of ketamine, norketamine, 5,6-dehydronorketamine and hydroxylated metabolites of norketamine in liquid/liquid extracts of (i) in vitro incubations with ketamine or norketamine and equine liver microsomes and (ii) plasma and urine of ponies receiving a target-controlled infusion of ketamine under isoflurane anesthesia. Hydroxynorketamine metabolites with the hydroxy group at the cyclohexanone ring could be shown to be formed stereoselectively both in vitro and in vivo. Due to the lack of ...
White SD, Foley JE, Spiegel IB, Ihrke PJ.Equine sarcoidosis is a rare, multisystemic, noncaseating, granulomatous and lymphoplasmacytic disease of unknown etiology. A recent report described a horse with granulomatous skin disease displaying histologic, electron microscopic, and polymerase chain reaction (PCR) findings consistent with equine herpesvirus 2 (EHV-2). Objective: To investigate the presence of EHV-2 and equine herpesvirus 1 (EHV-1) in 8 horses with sarcoidosis. Methods: Eight horses with sarcoidosis, reported previously. Methods: Retrospective study. PCR assays of the tissues were performed to detect DNA associated with E...
Garré B, Baert K, Nauwynck H, Deprez P, De Backer P, Croubels S.The aim of the current study was to investigate whether multiple oral dosing of valacyclovir could result in plasma concentrations exceeding the EC(50)-value of acyclovir against equine herpesvirus 1 (EHV1) during the majority of the treatment period. Additionally, we wanted to determine the concentration of acyclovir in nasal mucus and cerebrospinal fluid (CSF). Valacyclovir was administered to four horses and two ponies, three times daily, at a dosage of 40 mg/kg, for four consecutive days. Blood was collected prior to each administration and 1 h after dosing. Nasal mucus samples and CSF wer...
Poulin Braim AE, MacDonald MH, Bruss ML, Grattendick KJ, Giri SN, Margolin SB.To characterize effects of IV administration of pirfenidone on clinical, biochemical, and hematologic variables and circulating tumor necrosis factor (TNF)-alpha concentrations in horses after infusion of a low dose of endotoxin. Methods: 18 healthy adult horses. Methods: Horses were randomly assigned to 3 groups (n = 6 horses/group) and administered an IV infusion of 30 ng of endotoxin/kg or saline (0.9% NaCl) solution during a 30-minute period. Lipopolysaccharide-pirfenidone horses received endotoxin followed by pirfenidone (loading dose of 11.6 mg/kg and then constant rate infusion [CRI] at...
Echigoya Y, Sato T, Itou T, Endo H, Sakai T.The species-specific properties of LDH isozymes are essentially determined by M (muscle) and H (heart) subunit proteins encoded by the LDHA and LDHB genes, respectively. In the present study, we molecularly characterized the full-length equine lactate dehydrogenase A (eLDHA) and B (eLDHB) cDNAs. The eLDHA cDNA consisted of a 999-bp open reading frame (ORF), while the eLDHB and newly acquired bat LDHB consisted of a 1002-bp ORF, which is 3 bp shorter than the LDHB ORF of other registered mammals. The alignment of amino acid sequences showed that eLDHA acquired positively charged His 88 and 226,...
Bugno M, Słota E, Pieńkowska-Schelling A, Schelling C.Fluorescent in situ hybridisation (FISH) using a panel of molecular probes for all chromosome pairs obtained by chromosome microdissection of the domestic horse ( Equus caballus ) was used to diagnose karyotype abnormalities in 35 horses (32 mares, 2 stallions and 1 intersex), which were selected for the study due to infertility (23 horses), reduced fertility (10 horses) and developmental anomalies (2 horses). The use of the FISH technique with probes for each horse chromosome pair enabled the diagnosis of many different chromosome aberrations in this population. Among the horses analysed, 21 ...
Hosaka YZ, Takahashi H, Uratsuji T, Tangkawattana P, Ueda H, Takehana K.The aim of this study was to determine the characteristic differences in tendinocytes derived from tendons in the equine forelimb, superficial digital flexor tendon (SDFT), deep digital flexor tendon (DDFT) and common digital extensor tendon (CDET), in morphology, proliferation, collagen production ability and ability for synthesis of matrix metalloproteinases (MMPs). Significant differences were observed in cell number in vivo. The cellular number was largest in the SDFT and smallest in the CDET. The values of in vitro proliferation ratios and ability for synthesis of collagen and MMPs were l...
Labeda DP, Price NP, Kroppenstedt RM, Donahue JM, Williams NM, Sells SF.Two actinomycete strains, NRRL B-24165(T) and NRRL B-24166(T), isolated from lesions on equine placentas in Kentucky, USA, were analysed using a polyphasic taxonomic approach. On the basis of phylogenetic analysis of 16S rRNA gene sequences, morphological observations and the presence of ll-diaminopimelic acid as the diagnostic diamino acid in whole-cell hydrolysates, the new isolates clearly belonged to the genus Streptomyces. Analyses of the phylogenetic positions of strains NRRL B-24165(T) and NRRL B-24166(T) based on 16S rRNA gene sequences of all recognized species of the genus Streptomyc...
Alm YH, Sukjumlong S, Kindahl H, Dalin AM.Sex steroid hormone receptors have been identified in the adrenal gland of rat, sheep and rhesus monkey, indicating a direct effect of sex steroids on adrenal gland function. Methods: In the present study, immunohistochemistry using two different mouse monoclonal antibodies was employed to determine the presence of oestrogen receptor alpha (ERalpha) and progesterone receptor (PR) in the mare adrenal gland. Adrenal glands from intact (n = 5) and ovariectomised (OVX) (n = 5) mares, as well as uterine tissue (n = 9), were collected after euthanasia. Three of the OVX mares were treated with a sing...
Dirikolu L, Karpiesiuk W, Lehner AF, Hughes C, Granstrom DE, Tobin T.Triazine-based antiprotozoal agents are known for their lipophylic characteristics and may therefore be expected to be well absorbed following oral administration. However, although an increase in lipid solubility generally increases the absorption of chemicals, extremely lipid-soluble chemicals may dissolve poorly in gastrointestinal (GI) fluids, and their corresponding absorption and bioavailability would be low. Also, if the compound is administered in solid form and is relatively insoluble in GI fluids, it is likely to have limited contact with the GI mucosa, and therefore, its rate of abs...
Spriet M, Wisner ER, Anthenill LA, Buonocore MH.Seven isolated equine front limbs were used to establish the normal T1 relaxation time of equine superficial digital flexor tendon (SDFT), deep digital flexor tendon (DDFT), and suspensory ligament (SL) using magic angle magnetic resonance (MR) imaging. MR imaging of the metacarpi was performed with the limbs positioned at 55° (the magic angle) relative to the main magnetic field. Transverse spin-echo proton density and inversion recovery images were acquired. T1 relaxation time was calculated based on ratios of signal intensity determined from the different pulse sequences. T1 relaxation tim...
Albers L, Albers J, Dullin C, Staszyk C, Bienert-Zeit A.In clinical practice, early diagnosis of Equine Odontoclastic Tooth Resorption and Hypercementosis (EOTRH) and other resorptive incisor diseases is difficult to achieve. The radiographic appearance of subtle pathological changes has not been described in detail and might be confused with age-related changes. Objective: The study was performed to define typical radiographic signs of early incisor lesions and to evaluate the reliability of the radiographic findings. Methods: Descriptive and comparative study using post mortem clinical, radiographic, macroscopic and µCT examination. Methods: The...
Klei TR, Torbert B, Chapman MR, Foil L.Microfilariae of Onchocerca cervicalis were detected in midventral skin biopsy samples in 64 of 84 (76%) mixed-breed ponies greater than 2 years old from the Gulf Coast area and in 42 of 51 (82.4%) horses from Louisiana breeding herds. The number of microfilariae per 8 mm of biopsied skin (ponies) ranged from 1 to 21,570. The number of microfilariae per 6 mm of biopsied skin (horses) ranged from 8 to 55,600.
Cassotis NJ, Schiffman P.A 12-year-old Paso Fino mare was evaluated for a chronic nasal and ocular discharge. A calcification was identified eroding through the nasal mucosa of the middle meatus. Differential considerations for this mass included dacryolith, nasal calculus, or calcified tooth root abscess. Anatomical location and case history and progression supported a dacryolith. Following removal, the calculus was submitted for mineralogic analysis. The calculus was primarily carbonate hydroxylapatite (Ca10(PO4)3(CO3)3(OH)2) with a minor NaCl halite constituent. Dacryoliths, or nasolacrimal calculi, are an uncommon...
Stokol T, Serpa PBS, Brooks MB, Divers T, Ness S.Equine herpesvirus type 1 (EHV-1) is a major cause of infectious respiratory disease, abortion and neurologic disease. Thrombosis in placental and spinal vessels and subsequent ischemic injury in EHV-1-infected horses manifests clinically as abortion and myeloencephalopathy. We have previously shown that addition of heparin anticoagulants to equine platelet-rich plasma (PRP) can abolish ex vivo EHV-1-induced platelet activation. The goal of this study was to test whether platelets isolated from horses treated with unfractionated heparin (UFH) or low-molecular-weight heparin (LMWH) were resista...
Elce YA, Orsini JA, Blikslager AT.To assess expression of cyclooxygenase (COX)-1 and -2 in naturally occurring squamous cell carcinomas (SCCs) and the analogous normal tissues in horses. Methods: Tissue samples collected from 3 conjunctival, 2 vulvar, 4 preputial, and 5 penile SCCs during surgical excision in 14 horses and from corresponding body regions (conjunctiva [n = 5 horses], vulva [2], prepuce [3], and penis [3]) in 5 horses euthanized for reasons unrelated to neoplasia. Methods: Tissue samples were snap frozen in liquid nitrogen and stored at -80 degrees C until analysis. Protein was extracted from the frozen tissues,...
Pascoe PJ.A 16 year old Thoroughbred mare was presented to the Ontario Veterinary College because of an acute episode of colic. An exploratory laparotomy was performed and a neurofibroma was identified and successfully removed from the small colon. The clinical and pathological features of this case are discussed.
Mills PC, Roberts CA, Smith NC.To investigate the effects of ozone and airway inflammation on indices of oxidant injury in horses. Methods: 5 clinically normal horses and 25 horses referred for poor performance. Methods: Blood, tracheal wash, and bronchoalveolar lavage fluid samples were collected before and after ozone exposure (n = 5) or from clinical cases (n = 25), and were analyzed for reduced glutathione (GSH), glutathione disulfide (GSSG), and free and total iron (Fe) values. A scoring system (0 to 5) was used to assess airway inflammation on the basis of clinical signs and cytologic analysis of the tracheal wash and...
Munday JS, Gedye K, Daudt C, Chaves Da Silva F.Bovine papillomavirus (BPV) types 1 and 2 are recognized as the main cause of equine sarcoids. However, some studies report that up to a quarter of these tumors do not contain detectible BPV1 or BPV2 DNA. The absence of detectible BPV1 or BPV2 in these sarcoids suggests the possible involvement of other papillomavirus types. Currently, five are recognized to cause mesenchymal neoplasia after cross-species infection. In addition to BPV1 and BPV2, BPV13 has been associated with equine sarcoids in Brazil, BPV14 has been associated with feline sarcoids, and Ovis aries papillomavirus 2 caused a sa...
Murray DR, Ladds PW, Johnson RH, Pott BW.Extensive subcutaneous phycomycosis of the lower hindlimb developed over a period of 8 months in a Thoroughbred filly. There was no response to treatments such as trichlorphon, sodium iodide, or etisazole. Extension of the limb lesion over the following 3 months was associated with an enlarged inguinal lymph node, which was removed. Characteristic phycomycotic lesions were observed in the node, and a fungus having the morphologic features of Hyphomyces destruens was isolated from both the limb and nodal lesions.
Honnas CM, Dabareiner RM, McCauley BH.Because of the hoof capsule, surgery of the equine foot is often perceived to be quite difficult. Knowledge of the specific disease entities that require surgical intervention as well as an in-depth understanding of the anatomy of the tissues beneath the hoof capsule is a definite prerequisite to successful surgical treatment. This article details the surgical approaches used to treat septic navicular bursitis, septic pedal osteitis, infection of the collateral cartilages, and keratomas. The principles used to treat these conditions can be applied to a variety of other conditions for which acc...
Jann HW, Stein LE, Good JK.Size 3-0 polydioxanone was used as a single strand, single braid (3 strands), or double braid (6 strands) to create six suture material-pattern combinations for equine tenorrhaphy: single-strand locking loop, single-braid locking loop, double-braid locking loop, single-strand three-loop pulley, single-braid three-loop pulley, and double-braid three-loop pulley. Maximum load to failure for the single-strand locking loop (46.1 +/- 2.9 newtons [N]) was less than for all other sutures (range, 103-155 N). The load required to form a 2 mm gap between tendon ends was greater for the single-braid thre...
Németh F, Dik KJ.A sagittal fracture of the navicular bone in five horses was treated by means of lag screw. Intra-operative radiographic monitoring and a specially developed guide apparatus was necessary to implant the screw precisely along the transverse axis of the navicular bone. Internal fixation resulted in progressive radiographic narrowing of the fracture zone. In all five patients the fracture healed (bony union) without superfluous callus formation.
Dacre IT, Shaw DJ, Dixon PM.Histological measurements of dimensions of primary, regular secondary and irregular secondary dentine, pulp diameter and assessment of the levels of predentine, resting lines and enlarged areas of intertubular dentine were performed in apically infected mandibular and maxillary cheek teeth (CT). These examinations showed significantly reduced regular and irregular secondary dentine thickness in diseased as compared to control CT, with 21/26 infected maxillary CT and 15/18 infected mandibular CT having reduced regular secondary dentine (varying between 27.4% and 89.1% reduced secondary dentine ...
Weiss DJ, Evanson OA, Fagliari JJ, Valberg S.To determine whether platelets become activated and form platelet-neutrophil aggregates during near-maximal treadmill exercise in horses. Methods: 4 Thoroughbreds. Methods: Horses were subjected to 4 standardized exercise tests on a treadmill, and blood samples were collected before exercise, at treadmill speed of 12 m/s, and 5 minutes after exercise. Flow cytometric techniques were used to identify activated platelets, and flow cytometric and microscopic techniques were used to identify platelet-neutrophil aggregates. Results: Platelet-neutrophil aggregates increased from 2.8 +/- 0.4% at rest...
Dubin A, Potempa J, Kurdowska A, Pajdak W, Koj A.Alpha-1-proteinase inhibitors isolated from plasmas of horse, ox, pig, rabbit and man were used for determination of some kinetic parameters of interaction with three horse leucocyte proteinases and bovine pancreatic trypsin and chymotrypsin. Effective molar ratio of enzyme-to-inhibitor, inactivation rate constant and inhibition constant were measured. In horse, ox, pig and rabbit two principal electrophoretic forms of alpha 1-PI could be distinguished. Both forms effectively inhibited trypsin but usually only one form reacted promptly and stoichiometrically with chymotrypsin and leucocyte ela...
Galera PD, Brooks DE.Keratomycosis in the horse exists in several unique clinical forms. This paper discusses the diagnosis and clinical management of keratomycosis in the horse associated with tear film instability, epithelial keratopathy, subepithelial infiltrates, superficial and deep ulcers, plaques, melting ulcers, descemetoceles, iris prolapse, and stromal abscesses. Prompt diagnosis and aggressive treatment of equine keratomycosis can make a major difference in the maintenance of a cosmetic and visual eye.
Sedrish SA, Moore RM, Valdes-Vasquez MA, Haynes PF, Vicek T.Pythiosis, caused by Pythium insidiosum, is a common cutaneous granulomatous disease in horses. Surgical removal is the most common treatment; however, high rates of recurrence have been reported. Results of examination of 2 horses with pythiosis granulomas in which a neodymium:yttrium-aluminum-garnet laser was used to photoablate the bed after removal are reported. The mass had not recurred in either horse 1 year after surgery. Photoablation results in collateral thermal necrosis and may kill organisms that have infiltrated surrounding tissues, thus reducing the risk of recurrence.
Heath TJ, Nikles SA.Secondary lymphoid nodules in lymph nodes of the horse are surrounded by a network of lymph sinuses, including the subcapsular sinus and its extensions around tabeculae, tubular and tubule-like sinuses deeper in the cortex, and sinuses between cord-like projections of cortical tissue. The precise role of this close association between sinuses and nodules in the transport of immune complexes, cells and cytokines is not known.
Spriet M, Murphy B, Vallance SA, Vidal MA, Whitcomb MB, Wisner ER.Magic angle magnetic resonance (MR) imaging consists of imaging tendons at 55° to the magnetic field. In people, magic angle MR imaging is valuable for detection of chronic tendon lesions and allows calculation of tendon T1 values. Increased T1 values occur in people with chronic tendinopathy. The T1 values of normal equine tendons have been reported but there are no available data for abnormal equine tendons. Twelve limbs were studied. Two limbs had diode laser tendon lesions induced postmortem, four limbs had diode laser tendon lesions induced in vivo and six limbs had naturally occurring t...
Meireles MC, Riet-Correa F, Fischman O, Zambrano AF, Zambrano MS, Ribeiro GA.Equine pythiosis was studied in five animals from two farms located in a swampy region of southern Brazil (Rio Grande do Sul State). Granulomatous lesions exuding necrotic material and containing a central yellow and firm tissue core, the 'kunker', were observed on the top of the nose of one horse, on the abdomen of two horses and on the hind limbs of two other animals. Direct microscopic preparations, histopathological examination of lesion material, and macroscopic and microscopic characteristics of the isolates confirmed the diagnosis of pythiosis. Surgical intervention of the inflammatory ...
Dong B, Bergman D, Holst BS.Heterophilic antibodies in serum and plasma can interfere with mammalian antibodies in immunoassays and result in false test results, usually false positive. Although studies screening for heterophilic antibodies as well as elimination studies have been conducted in dogs and cats, knowledge of the presence of heterophilic antibodies in other species in veterinary medicine is limited. In this study, a 2-site sandwich-type interference assay that detects anti-mouse antibodies was used to detect heterophilic antibodies in a population of horses treated in an animal hospital. Results: A total of 1...
Beck C, Charles JA, Maclean AA.A 16-year-old thoroughbred stallion developed sudden swelling of the left testicle. The stallion had previously been regarded as a unilateral cryptorchid. Ultrasound examination of the left testicle revealed a diffusely heterogeneous parenchyma. The testicle was diffusely hypoechoic with ill defined regions of hyperechogenicity giving the appearance of hypoechoic nodules throughout the testicular parenchyma. No normal testicular tissue was identifiable. An echogenic band, representing a pseudocapsule could be seen surrounding the testicle. Histopathologic diagnosis a seminoma.
Hatfield CL, McDonell WN, Lemke KA, Black WD.To determine the pharmacokinetics and toxic effects associated with IV administration of lithium chloride (LiCl) to conscious healthy horses. Methods: 6 healthy Standardbred horses. Methods: Twenty 3-mmol boluses of LiCl (0.15 mmol/L) were injected IV at 3-minute intervals (total dose, 60 mmol) during a 1-hour period. Blood samples for measurement of serum lithium concentrations were collected before injection and up to 24 hours after injection. Behavioral and systemic toxic effects of LiCl were also assessed. Results: Lithium elimination could best be described by a 3-compartment model for 5 ...
Atiba A, Ghazy A, Hamad MH.Cutaneous pythiosis in horses is a chronic ulcerative granulomatous disease caused by the oomycete Pythium insidiosum. Objective: The objective of the present study was to evaluate the response of cutaneous pythiosis in horses to surgical excision and topical dimethyl sulphoxide (DMSO). Methods: Thirty horses were presented clinically with pruritus, fistulae discharging serosanguineous fluid, and output kunkers in different body areas (limb, abdomen, neck, and face). The clinical diagnosis was confirmed by isolation of the causative agent and histopathology. All animals were treated by surgica...
Toscan G, Cezar AS, Pereira RC, Silva GB, Sangioni LA, Oliveira LS, Vogel FS.Several formulations of macrocyclic lactones (abamectin, ivermectin, moxidectin), including ivermectin combined with pyrantel (tetrahydropyrimidine) and ivermectin combined with praziquantel (pyrazinoisoquinolin derivative), were tested regarding their efficacy to control gastrointestinal nematodes of horses on a stud farm in southern Brazil. In addition, we tested a pharmaceutically produced generic paste containing ivermectin 4%. Similar formulations of avermectins had different efficacies measured by reduction of EPG. Levels of efficacy of the tested drugs varied against Strongylus edentatu...
Townsend WM, Jacobi S, Bartoe JT.Presently, intraocular lenses (IOLs) are not routinely implanted after equine cataract surgery. Subsequently, horses are visual but markedly farsighted (hyperopic). This report describes the surgical results and visual status after phacoemulsification and implantation of IOLs in mature horses with spontaneous cataracts. Six eyes of 5 mature horses underwent phacoemulsification and implantation of a +14 diopter (D) foldable IOL. Recheck ocular examinations were performed at 1, 4 and 24 weeks post operatively. Refractive error was recorded at 4 weeks post operatively. Visual status, refractive e...
Brown CM, Kaneene JB, Walker RD.A survey of 584 veterinarians in equine practice was performed to determine their intramuscular injection techniques and the influence of those techniques on the development of clostridial myositis or cellulitis. Usable responses were obtained from 439 veterinarians (75.2%). Of these, 414 used a new needle and syringe for each injection, 241 swabbed the site with a cleansing/disinfectant agent, and 242 swabbed the top of multidose injection bottles with a similar solution. Only 2 clipped the hair at the injection site. Twenty eight of the respondents reported that at least 1 horse developed a ...
Seabaugh KA, Schumacher J.Many urogenital procedures of the mare are commonly performed with the mare standing. Ovariectomy via colpotomy was described as early as 1903, and the Caslick vulvoplasty was first described in 1937. As knowledge expands and instruments become more specialized, techniques will improve. With the introduction of laparoscopy, clinicians have not only been able to improve the previously described urogenital procedures but also to devise new procedures. This article describes multiple surgeries of the female urogenital tract, all of which can be performed with the mare standing, and describes a va...
