"Horses" is a broad topic that encompasses various aspects of equine biology, behavior, and management. This category includes studies on the anatomy, physiology, and genetics of horses, as well as their behavior, nutrition, and care. Research in this area may also cover the historical and cultural significance of horses, their roles in agriculture, sport, and therapy, and the challenges associated with their conservation and welfare. The page aggregates peer-reviewed research articles and scholarly studies that explore the multifaceted relationships between humans and horses, examining both scientific and socio-economic perspectives.
Celaya R, Ferreira LM, García U, Rosa García R, Osoro K.As the number of horses is steadily increasing in Cantabrian less-favoured areas, mostly occupied by nutritionally poor heathland communities, the objective of this research was to study and compare diet selection and performance of crossbred horses and beef cattle (Asturiana de los Valles breed) grazing these areas during the summer. A total of 20 cows (seven lactating their calves and thirteen dry) and 20 mares (eight lactating their foals and twelve dry) were managed during 3 years on a heathland area from June to September and October. The proportion of grass (mostly Pseudarrhenatherum lon...
Leisson K, Alev K, Kaasik P, Jaakma Ü, Seene T.This study investigates the myosin heavy chain (MyHC) isoform composition in the gluteus medius muscle of the Akhal-Teke horses using SDS-PAGE (sodium dodecyl sulfate polyacrylamide gel electrophoresis). Fifteen horses aged between 1.5 and 23.5 years were used in this study and divided into three age groups: 1.5 to 4 (n = 6), 9 to 13 (n = 5) and 18.5 to 23.5 years (n = 4). The average content of the MyHC I isoform was 11.72 ± 1.07% (variation between individuals: 7.09% to 20.14%). The relative content of the MyHC IIa and IIx isoforms was subsequently 38.20 ± 1.46% (30.73% to 48.78%) and 50.0...
Virén T, Huang YP, Saarakkala S, Pulkkinen H, Tiitu V, Linjama A, Kiviranta I, Lammi MJ, Brünott A, Brommer H, Van Weeren R, Brama PA, Zheng YP....The aim of this study was to compare sensitivity of ultrasound and optical coherence tomography (OCT) techniques for the evaluation of the integrity of spontaneously repaired horse cartilage. Articular surfaces of horse intercarpal joints, featuring both intact tissue and spontaneously healed chondral or osteochondral defects, were imaged ex vivo with arthroscopic ultrasound and laboratory OCT devices. Quantitative ultrasound (integrated reflection coefficient (IRC), apparent integrated backscattering coefficient (AIB) and ultrasound roughness index (URI)) and optical parameters (optical refle...
Purzyc H, Kobryńczuk F, Bojarski J.The purpose of this study has been to evaluate the applicability of discriminant function analysis to determine gender dimorphism in Hucul horses, based on morphological indices obtained in different stages of life. A total of 243 horses, divided into six age groups, have been examined in its course. For each horse we have measured 12 metric traits, which were then used to calculate 13 biometric indices commonly used in horse breeding in Poland. These have become the basis for defining functions classifying the animals by gender in each of the six age groups. This study answers the question of...
Ault A, Zajac AM, Kong WP, Gorres JP, Royals M, Wei CJ, Bao S, Yang ZY, Reedy SE, Sturgill TL, Page AE, Donofrio-Newman J, Adams AA, Balasuriya UB....Equine influenza A (H3N8) virus infection is a leading cause of respiratory disease in horses, resulting in widespread morbidity and economic losses. As with influenza in other species, equine influenza strains continuously mutate, often requiring the development of new vaccines. Current inactivated (killed) vaccines, while efficacious, only offer limited protection against diverse subtypes and require frequent boosts. Research into new vaccine technologies, including gene-based vaccines, aims to increase the neutralization potency, breadth, and duration of protective immunity. Here, we demons...
Asadi F, Asadian P, Shahriari A, Pourkabir M, Kazemi A.Patterns of serum biochemical parameters vary among horse breeds. The objective of the present study was to compare serum lipoproteins of Iranian Caspian ponies with those of other horses (Arabs and Thoroughbreds) in the Iranian region. Serum lipoprotein values were determined by agar-agarose gel electrophoresis and measured by scan densitometry. Moreover, serum triglyceride and cholesterol concentrations were determined and the results were analysed by one-way analysis of variance. Serum triglyceride and cholesterol values were 1.13 +/- 0.23 and 2.38 +/- 0.18 mmol/l in Caspian ponies, 1.96 +/...
De Marco M, Miraglia N, Peiretti PG, Bergero D.Several studies have reported data on comparisons between two methods: the total collection of feces and the internal markers method. The aim of this study was to assess the apparent digestibility of two concentrates and to compare the apparent digestion coefficients using the total collection of feces and acid-insoluble ash (AIA) as the internal marker method. In 2009, six adult geldings aged between 3 and 11 years, with an average weight per trial of 543, 540 and 542 kg, respectively, were used to determine the apparent digestibility by means of three in vivo digestibility trials on hay, hay...
Mori E, Borges AS, Delfiol DJ, Oliveira Filho JP, Gonçalves RC, Cagnini DQ, Lara MC, Cunha EM, Villalobos EM, Nassar AF, Castro AM, Brandao PE....This report describes the first detection of an equine herpesvirus 1 (EHV-1) neuropathogenic variant (G2254/D752) in Brazil from a case of fatal equine herpesvirus myeloencephalopathy (EHM) in a mare. The results of nucleotide sequencing of the EHV-1 ORF30 gene showed that two other Brazilian EHV-1 isolates from EHM cases are representatives of the non-neuropathogenic variant (A2254/N752), suggesting that other unidentified factors are probably also involved in the neuropathogenicity of EHV-1 in horses. These findings will contribute to the epidemiological knowledge of EHV-1 infection in Brazi...
Moraveji M, Hosseini MH, Amrabadi O, Rahimian A, Namazi F, Namavari M.Neospora caninum, an apicomplexan protozoan parasite, is recognized as a major cause of abortion in cattle. However, limited information is presently available on the seroprevalence of Neospora antibodies in horses worldwide. The aim of the present study is to determine serological prevalence of Neospora infection in horses in Iran. Blood samples were obtained from 200 horses and tested for serum antibodies against Neospora spp. by the Neospora modified direct agglutination test (N-MAT). Antibodies were found in 64 (32%) horses being tested with titers of 1:80. This is the first serological su...
Knox J, Cowan RU, Doyle JS, Ligtermoet MK, Archer JS, Burrow JN, Tong SY, Currie BJ, Mackenzie JS, Smith DW, Catton M, Moran RJ, Aboltins CA....Murray Valley encephalitis virus (MVEV) is a mosquito-borne virus that is found across Australia, Papua New Guinea and Irian Jaya. MVEV is endemic to northern Australia and causes occasional outbreaks across south-eastern Australia. 2011 saw a dramatic increase in MVEV activity in endemic regions and the re-emergence of MVEV in south-eastern Australia. This followed significant regional flooding and increased numbers of the main mosquito vector, Culex annulirostris, and was evident from the widespread seroconversion of sentinel chickens, fatalities among horses and several cases in humans, res...
Smith MA, Dyson SJ, Murray RC.To determine the reliability of 2 magnetic resonance imaging (MRI) systems for detection of cartilage and bone lesions of the equine fetlock. Objective: To test the hypotheses that lesions in cartilage, subchondral and trabecular bone of the equine fetlock verified using histopathology can be detected on high- and low-field MR images with a low incidence of false positive or negative results; that low-field images are less reliable than high-field images for detection of cartilage lesions; and that combining results of interpretation from different pulse sequences increases detection of cartil...
Sommerauer S, Muelling CK, Seeger J, Schusser GF.Anaesthesia of the external ear canal (external acoustic meatus) is usually performed by blocking both the great and internal auricular nerves by regional infiltration. However, exact landmarks for blocking the internal auricular nerve to accomplish effective anaesthesia have not been described yet. In this study, detailed anatomical dissection of the equine external ear canal and its nerve supply was carried out on fifteen cadaver heads. Tissue samples of the dissected nerves were taken from two cadaver heads processed and were evaluated microscopically. Prior to the dissection, the region of...
Zipplies JK, Hauck SM, Eberhardt C, Hirmer S, Amann B, Stangassinger M, Ueffing M, Deeg CA.In equine recurrent uveitis (ERU), immune reactions are directed toward known antigens like S-antigen, interphotoreceptor retinoid-binding protein, and cellular retinalaldehyde-binding protein, and anti-retinal antibodies were detected in vitreous samples. The aim of this study was the investigation of intraocular immunoglobulin M (IgM) reactivities to retinal proteome. Methods: Retina was separated by one- and two-dimensional gel electrophoresis and blotted semidry on PVDF membranes. To identify intraocular IgM antibody responses to retinal tissue, blots were incubated with vitreous samples o...
Fuchs S, Klier J, May A, Winter G, Coester C, Gehlen H.Delivering active ingredients using biocompatible and biodegradable carriers such as gelatin nanoparticles (GNPs) to the lung constitutes a promising non-invasive route of administration. However, the pulmonary delivery of nanoparticle-based immunotherapy is still a field that requires more clarification. In this study, GNPs loaded with cytosine-phosphate-guanine oligodeoxynucleotides (CpG-ODN)-loaded and plain GNPs were aerosolised either by a conventional pressured metered dose inhaler (pMDI) or by active or passive vibrating-mesh (VM) nebulisers. GNP sizes after nebulisation by active and p...
Piskoty G, Jäggin S, Michel SA, Weisse B, Terrasi GP, Fürst A.There are no detailed studies describing the resistance of equine tibiae and radii to side impact loads, such as a horse kick and a better understanding of the general long bone impact behavioural model is required. Objective: To quantify the typical impact energy required to fracture or fissure an equine long bone, as well as to determine the range and time course of the impact force under conditions similar to that of a horse kick. Methods: Seventy-two equine tibiae and radii were investigated using a drop impact tester. The prepared bones were preloaded with an axial force of 2.5 kN and wer...
Finno CJ, Aleman M, Ofri R, Hollingsworth SR, Madigan JE, Winfield L, Bannasch DL.Neuroaxonal dystrophy (NAD) is a disease characterized by the sudden onset of neurologic signs in horses ranging from 4 to 36 months of age. Equine degenerative myeloencephalopathy (EDM), a disease that has been associated with low vitamin E concentrations, is considered a more advanced form of NAD. The objective of this report is to describe the electrophysiological features of NAD/EDM in American Quarter horses (QHs). HORSES: Six NAD/EDM-affected QHs and six unaffected QHs were evaluated by ophthalmic examination and electroretinography. Five of the NAD/EDM-affected QH and five unaffected QH...
McGreevy PD, Corken RA, Salvin H, Black CM.The use of whips by jockeys is an issue. The current study viewed opportunistic high-speed footage of 15 race finishes frame-by-frame to examine the outcomes of arm and wrist actions (n = 350) on 40 horses viewed from the left of the field. Any actions fully or partially obscured by infrastructure or other horses were removed from the database, leaving a total of 104 non-contact sweeps and 134 strikes. For all instances of arm actions that resulted in fully visible whip strikes behind the saddle (n = 109), the outcomes noted were area struck, percentage of unpadded section making conta...
Linardi RL, Stokes AM, Andrews FM.Methadone is an effective analgesic opioid that may have a place for the treatment of pain in horses. However, its absorption seems to be impaired by the presence of a transmembrane protein, P-glycoprotein, present in different tissues including the small intestine in other species. This study aims to determine the effect of the P-glycoprotein on methadone flux in the equine intestinal mucosa, as an indicator of in vivo drug absorption. Jejunum tissues from five horses were placed into the Ussing chambers and exposed to methadone solution in the presence or absence of Rhodamine 123 or verapami...
Friedman R.The value of providing equine reproductive services in ambulatory setting is well established. Ambulatory practice has been, and will most likely continue to be, the primary provider of equine reproductive veterinary services. The limitations for performing various reproductive procedures in an ambulatory setting are those imposed by the amount of equipment and supplies that must be brought to the patient, as well as those imposed when procedures require additional assistance. This is analogous to human medical care: the ambulance cannot substitute for a hospital but it can certainly provide s...
Gryspeerdt AC, Vandekerckhove AP, Baghi HB, Van de Walle GR, Nauwynck HJ.Equine herpes virus (EHV)-1 replicates in the epithelial cells of the upper respiratory tract and reaches the lamina propria and bloodstream in infected mononuclear cells. This study evaluated expression of the late viral proteins gB, gC, gD and gM in respiratory epithelial and mononuclear cells using: (1) epithelial-like rabbit kidney cells and peripheral blood mononuclear cells infected with EHV-1 in vitro; (2) an equine ex vivo nasal explant system; and (3) nasal mucosa tissue of ponies infected in vivo. The viral proteins were expressed in all late-infected epithelial cells, whereas expres...
Seo JP, Tsuzuki N, Haneda S, Yamada K, Furuoka H, Tabata Y, Sasaki N.A three dimensional scaffold is essential in mesenchymal stem cells (MSCs) delivery in cell-based therapy for facilitating cell adherence, migration, proliferation, and differentiation. The objectives of this study were to evaluate the possibility of β-tricalcium phosphate incorporated gelatin sponges (Gelatin/β-TCP sponge) as scaffolds for equine MSCs and to examine the effects of seeding density and seeding method on the proliferation of equine MSCs in the Gelatin/β-TCP sponges. Mononuclear cells and MSCs isolated from bone marrow were seeded into Gelatin/β-TCP sponges at different densi...
Hamond C, Martins G, Lawson-Ferreira R, Medeiros MA, Lilenbaum W.The objective of this study was to demonstrate the presence of leptospires in equine urine, as evidence for a potential role of horses in transmission of this organism. Thoroughbred horses (aged 2-5 years, n = 276) from Rio de Janeiro, Brazil, were studied. After a severe storm, the premises of the animals remained flooded for 72 h. Blood samples for serology were collected on days 20 and 35 (day of storm = day 0). On day 20, 132 (47·8%) horses were seroreactive (titre ≥200) and, of these, 23 (31·0%) had increased antibody titres on day 35. Furthermore, 34 urine samples (for PCR and cultur...
Schumacher J, Schumacher J, Wilhite R.Clinical experiences indicate that centesis of the lateral compartment of the femorotibial joint is often unsuccessful. Objective: To determine the accuracy of 2 published and 2 unpublished techniques of centesis of the lateral compartment of the femorotibial joint. Objective: It was hypothesised that a drug can be administered into the lateral compartment of the femorotibial joint via a diverticulum of this joint that surrounds the medial aspect of the long digital extensor tendon and that this technique is more accurate than described techniques of centesis of this compartment. Methods: Twen...
Denwood MJ, Love S, Innocent GT, Matthews L, McKendrick IJ, Hillary N, Smith A, Reid SW.The faecal egg count (FEC) is the most widely used means of quantifying the nematode burden of horses, and is frequently used in clinical practice to inform treatment and prevention. The statistical process underlying the FEC is complex, comprising a Poisson counting error process for each sample, compounded with an underlying continuous distribution of means between samples. Being able to quantify the sources of variability contributing to this distribution of means is a necessary step towards providing estimates of statistical power for future FEC and FECRT studies, and may help to improve t...
van Galen G, Saegerman C, Marcillaud Pitel C, Patarin F, Amory H, Baily JD, Cassart D, Gerber V, Hahn C, Harris P, Keen JA, Kirschvink N, Lefere L....Appropriate management of atypical myopathy (AM) requires the establishment of an accurate diagnosis and prognosis. Furthermore, preventive measures to avoid AM need to be refined. Objective: The aims of the study were as follows: 1) to improve the diagnosis of AM; 2) to identify prognostic predictors; and 3) to refine recommended preventive measures based on indicators of risk factors. Methods: An exploratory analysis of cases in Europe between 2006 and 2009 reported to the Atypical Myopathy Alert Group was conducted. Based on clinical data, reported cases were allocated into 2 groups: ...
Canisso IF, Beltaire KA, Bedford-Guaus SJ.Premature luteal demise or luteal insufficiency is not well characterised as a cause of pregnancy loss in domestic species, including horses. In this report, a mare inseminated with cooled-transported semen at our facility returned for a routine pregnancy diagnosis at 15 days post ovulation. Ultrasonography per rectum revealed endometrial oedema and the absence of visual indication of a corpus luteum on either ovary. Nonetheless, an embryonic vesicle small for the gestational age was identified. Daily oral altrenogest treatment was implemented immediately. Serum progesterone concentration was ...
Roberts VL, Perkins JD, Skärlina E, Gorvy DA, Tremaine WH, Williams A, McKane SA, White I, Knottenbelt DC.Idiopathic headshaking is often a facial pain syndrome, but a diagnostic protocol has not been described. In a previous study, caudal compression of the infraorbital nerve for treatment offered a fair success rate, but low case numbers and short follow-up time were limitations. Objective: To describe a diagnostic protocol for headshaking, examining the role of bilateral local analgesia of the posterior ethmoidal nerve (PET block). To report longer-term follow-up after surgery of the original cases and further cases and to determine whether changes to the technique influence success rates and c...
Watts AE, Fubini SL.This report describes a modification of the parainguinal approach for removal of cystic calculi: a ventral midline laparotomy-guided parainguinal laparocystotomy. The ventral midline approach to the abdomen is rapid and routinely used by equine surgeons. With an arm introduced to the abdomen via the ventral midline, the surgeon is able to select the ideal parainguinal laparotomy incision location that allows bladder exteriorisation with the minimum amount of tension. Because the surgeon's hand is introduced via the ventral midline incision, the parainguinal incision can be sized to just allow ...
Gonçalves R, Malalana F, McConnell JF, Maddox T.For accurate interpretation of magnetic resonance (MR) images of the equine brain, knowledge of the normal cross-sectional anatomy of the brain and associated structures (such as the cranial nerves) is essential. The purpose of this prospective cadaver study was to describe and compare MRI and computed tomography (CT) anatomy of cranial nerves' origins and associated skull foramina in a sample of five horses. All horses were presented for euthanasia for reasons unrelated to the head. Heads were collected posteuthanasia and T2-weighted MR images were obtained in the transverse, sagittal, and do...
Kenny LB, Ward D, Robson MG, Williams CA.Many methods exist for estimating species composition, but few studies compare those useful in improved horse pastures. The objective of this study was to examine 4 techniques for estimating desirable forage species composition in 2 cool-season horse pastures based on prevalence estimates, repeatability, bias, and practicality, and to select a method for use in a subsequent grazing study. The techniques included Equine Pasture Evaluation Disc (EPED), Line-Point Intercept with 3 transects of 50 observations each (LPI 3-50), LPI with 5 transects of 30 observations each (LPI 5-30), and Step Point...
Tatarniuk DM, Bell C, Carmalt JL.Disease of the paranasal sinuses of the horse is common and treatment often involves lavage and sometimes surgery. The development of minimally-invasive, sinus-specific treatments, such as balloon sinuplasty, requires a thorough understanding of this complex anatomical region. To improve this understanding, 10 heads from dead horses of various ages were grossly dissected. The heads were transected sagittally and each half was dissected to expose the left and right nasomaxillary apertures and associated structures which were then photographed and measured. Entrances from the rostral and caudal ...
Hreinsdóttir I, Hreinsdóttir A, Eydal M, Tysnes KR, Robertson LJ.In Iceland, there is at least 1 horse for every 5 human inhabitants, mostly kept on uncultivated rangelands. Although the Icelandic horse is considered robust compared with other breeds, it is nevertheless susceptible to disease. Few studies have investigated the prevalence of intestinal parasites in horses in Iceland. The purpose of this study was to determine the prevalence of the tapeworm, Anoplocephala perfoliata, in horses in Iceland and to explore associations between intensity of infection and the severity of macroscopic pathological lesions in this population. In addition, the relation...
Fazio E, Medica P, Trifiletti C, Ferlazzo A.The objective of this study was to compare in detail the total and free iodothyronines' pattern of mares from the first ovulation of the year over an extended period of 12 weeks. A total of 20 mares were used in the study. The mares were classified into two groups: mares mated at the ovulation (n = 10) used as observational group and mares unmated at the ovulation (n = 10) used as control group. Serum total and free triiodothyronine (T3, fT3) and thyroxine (T4, fT4) levels were measured in baseline conditions at the first ovulation of year and once a week until 12 weeks later. For the experi...
O'Callaghan MW, Pascoe JR, O'Brien TR, Hornof WJ, Mason DK.This study was initiated to determine if the extent and intensity of lung lesions associated with exercise-induced pulmonary haemorrhage (EIPH) in horses could be predicted from thoracic radiographs. Sets of thoracic radiographs from 24 horses with varied histories of EIPH were subjectively coded for radiographic quality, and perceived extent and intensity of diffuse interstitial opacity by three radiologists who had no knowledge of the corresponding autopsy results. Codes assigned from radiographs for the chosen parameters were compared with coded estimates of lung surface staining assigned a...
Bonicel J, Couchoud P, Foglizzo E, Desnuelle P, Chapus C.The complete sequence of the 96 residues composing horse colipase B has been determined by automated analysis of the intact protein, of two CNBr peptides and two tryptic peptides arising, respectively, from the citraconylated chain and from the unreduced protein. The single histidine of the protein is located at position 29 as in horse colipase A. His86, present in the C-terminal region of the pig cofactor and supposed to play a role in the folding molecule, is not conserved in horse B. Large pieces of the pig and horse B chains were found to be identical or very similar, especially the N-term...
Sharp DC, Vernon MW, Zavy MT.Oestrous behaviour, ovarian follicular development, ovulation and changes in hair coat were observed in Pony mares which were unoperated, sham-ganglionectomized control or bilaterally superior cervical ganglionectomized. Surgery was performed during the winter anoestrus (1975--1976). Reproductive patterns in all groups were similar during the first breeding season (1976) after operation but in ganglionectomized mares the onset of the next breeding season (date of first ovulation in 1977), the pattern of follicular development, date of first oestrus and pattern of hair coat changes were all sig...
Jones JH, Ohmura H, Stanley SD, Hiraga A.Human athletes run faster and experience fewer injuries when running on surfaces with a stiffness 'tuned' to their bodies. We questioned if the same might be true for horses, and if so, would running on surfaces of different stiffness cause a measurable change in the amount of energy required to move at a given speed? Objective: Different brands of commercial treadmills have pans of unequal stiffness, and this difference would result in different metabolic power requirements to locomote at a given speed. Methods: We tested for differences in stiffness between a Mustang 2200 and a Säto I comme...
Tulamo RM, Houttu J, Tupamäki A, Salonen M.To investigate the presence of large molecular weight (MW) proteoglycans (PG) and hyaluronate (HA) in synovial fluid (SF) from horses with various arthritides and from control joints. Methods: Horses with acute (< 2 weeks) or chronic (> 4 weeks) lameness were examined by clinical examination, intrasynovial anesthesia, radiography, arthroscopy, and SF analysis. Joints were grouped on the basis of diagnosis: acute traumatic arthritis, chronic traumatic arthritis (with a subgroup of degenerative joint disease), intra-articular fracture, and infectious arthritis. Methods: 31 horses with arthritis ...
Sumbria D, Singla LD, Sharma A, Bal MS, Kumar S.Multiplex PCR for simultaneous detection of Trypanosoma evansi and Theileria equi in single-step reaction was optimized and employed on 108 equids (99 horses and 9 donkeys/mules) blood samples collected from two agro-climatic zones (Sub-mountain undulating zone and Undulating plain zone) of Punjab to evaluate the status of concurrent infection and associated risk factors. The amplification products of 257 and 709 bp targeting repetitive nucleotide sequence of variable surface glycoproteins of T. evansi and 18S rRNA gene of T. equi, respectively expressed high fidelity of the primer pairs with ...
Caspar GL, Dhand NK, McGreevy PD.Human preferences for certain morphological attributes among domestic animals may be entirely individual or, more generally, may reflect evolutionary pressures that favor certain conformation. Artificial selection for attributes, such as short heads and crested necks of horses, may have functional and welfare implications because there is evidence from other species that skull shape co-varies with behaviour. Crested necks can be accentuated by flexion of the neck, a quality that is often manipulated in photographs vendors use when selling horses. Equine head-and-neck positions acquired through...
Dart AJ, Dowling BA, Smith CL.To report dynamic collapse of the apex of the left corniculate process under the right corniculate process into the airway at the dorsal apposition of the paired arytenoid cartilages during exercise as a cause of upper airway dysfunction in horses. Methods: Retrospective study. Methods: Fifteen horses with a history of poor performance and/or upper respiratory tract noise during exercise. Methods: Video recordings of all horses referred for upper airway evaluation using high-speed treadmill videoendoscopy (HSTV) between January 1998 and December 2003 were reviewed. Records of horses that devel...
Drudge JH, Lyons ET, Tolliver SC.Three formulations of cambendazole were evaluated for anthelmintic activity by critical testing method in 21 horses. Cambendazole suspension was administered via stomach tube at the dose rate of 10 mg/kg to 3 horses and at the dose rate of 20 mg/kg to 3 horses. Cambendazole paste was given intraorally to 8 horses, and the pellet formulation was fed to 7 horses at the dose rate of 20 mg/kg. Anthelmintic activity of cambendazole was similar for all dose rates and formulations. Gasterophilus intestinalis, Gasterophilus nasalis, Draschia megastoma, Anoplocephala perfoliata, and Anoplocephala magna...
Hazel SJ, Thrall MA, Severin GA, Lauerman LH, Lavach JD.Using routinely available clinical laboratory methods, aqueous humor samples were evaluated from 12 healthy dogs, 15 healthy cats, 7 healthy horses, and 6 healthy cows. Aqueous humor was almost acellular; cells that were present had degenerated beyond recognition. Protein concentration was low; only albumin was detectable on electrophoresis. Creatine phosphokinase and lactate dehydrogenase isoenzymes were not detected. Artifacts induced by sampling were insignificant compared with alterations in aqueous humor composition that occur with ocular diseases.
Cooley SD, Scrivani PV, Thompson MS, Irby NL, Divers TJ, Erb HN.Early diagnosis of high intracranial pressure (ICP) is critical for minimizing progressive brain injury due to reduced cerebral perfusion. In people, detecting enlargement of the optic nerve sheath diameter (ONSD) by transpalpebral ultrasonography has been found to be an accurate test for high ICP. Aims of this prospective, observational, cross-sectional study were to test hypotheses that (1) ultrasonographic measurement of ONSD would be repeatable in horses, (2) have acceptable interobserver agreement, and (3) would be correlated with age and body weight. The sample population included 48 hor...
Thibault CJ, Wilson DV, Robertson SA, Sharma D, Kinsley MA.To determine time to first passage of feces, total fecal piles and incidence of colic in the first 24 hours postprocedure in horses undergoing standing sedation with detomidine, or general anesthesia with or without detomidine. Methods: Retrospective cohort study. Methods: A total of 246 horses. Methods: Records of all horses that underwent standing sedation or general anesthesia between December 2012 and March 2016 were reviewed. Horses aged <6 months, admitted for colic or cesarean section, with inadequate data, and those not administered xylazine and/or detomidine were excluded. Records inc...
Sellon DC, Papich MG, Palmer L, Remund B.A two-way cross-over study of the pharmacokinetics of butorphanol after intravenous and intramuscular administration at 0.08 mg/kg in six adult horses was performed. Heparinized venous blood samples were obtained prior to drug administration and at 10, 20, 30, 45, 60, 120, 180, 240, and 360 min after IV injection. Samples were obtained at the same time points and at 6 h and 12 h after IM injection. Physical examination parameters were recorded at each time point. Plasma butorphanol concentrations were determined by high performance liquid chromatography. No significant differences in any physi...
Norman TE, Chaffin MK, Norton PL, Coleman MC, Stoughton WB, Mays T.Representatives from a herd of horses with acute onset of neurologic signs after administration of ivermectin presented for evaluation and treatment. Objective: Describe clinical signs of horses intoxicated by ingestion of Solanum sp. and administered ivermectin. Methods: Six of 11 affected unrelated horses presented for evaluation and treatment. The remaining 5 affected horses were treated at the farm. Four additional horses, housed separately, were unaffected. Methods: Case series is presented. Serum ivermectin concentrations were evaluated in the 6 hospitalized horses. The remnants of the t...
Whitehair KJ, Willits NH.To identify factors associated with various arterial partial pressures of oxygen (Pao2) in anesthetized horses. Methods: Retrospective study. Methods: 1,450 horses anesthetized a total of 1,610 times with isoflurane or halothane. Methods: Anesthesia records, particularly results of blood gas analyses, were reviewed, and horses were grouped on the basis of lowest Pao2. Results: For horses with lowest Pao2 < 120 mm Hg, those with low pulse pressure, that underwent anesthesia on an emergency basis, or that were males were more likely to have Pao2 < 80 mm Hg. For horses with lowest Pao2 <...
Serena A, Joiner KS, Schumacher J.Hemangiopericytoma (HP) is a well-recognized neoplasm arising from vascular pericytes that has been reported only in the dog and man. In this study, we describe a 14-year-old female Arabian horse that was presented for surgical excision of a 2-cm-diameter expansile subcuticular mass in the right lower eyelid. Histologically, the mass consisted of loosely arranged interlacing streams and storiform bundles of spindle cells that often formed distinct whorls around a central capillary and bundles of collagen (Antoni A-like pattern). Immunohistochemical analysis revealed strong diffuse cytoplasmic ...
Grosenbaugh DA, Hood DM.In this study, we described water-insoluble proteins extracted from the germinative regions (stratum internum and coronary band epithelium) and the cornified outer surface (stratum medium) of the equine hoof wall. Two major types of polypeptides were identified: the intermediate filaments (IF) and the IF-associated proteins. The IF, including keratins, composed a major portion of this fraction, had electrophoretic mobilities on sodium dodecyl sulfate-polyacrylamide gel electrophoresis in the range of 40 to 80 kDa, and reacted with acidic or basic keratin-specific monoclonal antibodies. Differe...
Posner LP, Kasten JI, Kata C.To document the suitability of intravenous propofol and ketamine following sedation with xylazine for routine anaesthetic induction in horses. Retrospective. 100 client-owned horses. Anaesthetic records were evaluated to determine: signalment, anaesthetic drug and dosages, need for additional induction agents, notation of any adverse events, duration of anaesthesia and recovery characteristics (rough or smooth, and rapid or prolonged). Horses were sedated with xylazine 0.99±(0.2) mg/kg intravenous and 23 horses were also administered butorphanol 0.02±(0.001) mg/kg intravenous. Horses were an...
Masset A, Staszyk C, Gasse H.Corrosion casts of blood vessels in the periodontium of cheek teeth from eight horses were observed three-dimensionally with a dissection microscope. Selected specimens were examined in a scanning electron microscope. Periodontal blood vessels communicated with those from the gingiva, the alveolar bone, and the apical region. In the upper jaw, there were anastomoses with the blood vessels of the mucosa of the maxillary sinus. The periodontal vascular system was organized in two or three layers. The peripheral layer was mainly composed of large venules, the inner one consisted of capillaries. I...
Bailly-Chouriberry L, Loup B, Popot MA, Dreau ML, Garcia P, Bruyas JF, Bonnaire Y.Since the availability on the European market of the vaccine Improvac® dedicated to male pig immunological castration, the risk of misuse of this product in horses is now considered as a threat for the horseracing industry. Immunological castration is not allowed by the racing codes (immune system, Article 6). Indeed, this vaccination against the hypothalamic hormone luteinizing hormone-releasing hormone or gonadotropin-releasing hormone (GnRH) will prevent the release from the anterior pituitary of luteinizing hormone and follicle stimulating hormone, which are required for the development a...
Pelletier N, Leith DE.Thoroughbred horses (TB) have no ventilatory response to added CO2 during near-maximal exercise. To see whether that reflects mechanical limits to ventilation or the control of breathing, we examined the effects of varying inspired O2 fraction (0.16, 0.21, or 0.30) in five normal TB standing quietly and galloping at 10 and 14 m/s on a level treadmill. We measured gas exchange (O2 consumption and CO2 production) and ventilation with a flow-through mask system. We also measured PO2, PCO2, and O2 contents in arterial and mixed venous blood and calculated cardiac output by using the Fick equation....
Cummings JF, Fubini SL, Todhunter RJ.Digital neurectomies, performed to relieve pain and lameness, are often complicated postoperatively by formation of painful neuromas. In this study attempts were made to deliver lethal doses of neurotoxin to the cell bodies of the transected digital nerve fibres via long-distance retrograde axon transport and, thereby, prevent the regenerative changes that lead to neuroma formation. After applying doxorubicin in various ways to the digital nerve stumps of ponies, degenerating or necrotic neurones appeared only sporadically in the spinal ganglia. Although doxorubicin was largely ineffective in ...
Hobo S, Matsuda Y, Yoshida K.A total of 350 thoroughbred racehorses found clinically as having coughs or abnormal breath sounds underwent endoscopic examination of the upper respiratory tract at rest. As a result, abnormal endoscopic findings were obtained in all horses, demonstrating that thoroughbred racehorses with a clinical abnormality in the respiratory system necessarily had disorders in the upper respiratory tract. Whereas 11 types of disorder were observed, a combination of three different types of disorder were found in the highest frequencies in 3-, 4- and 5-year-old horses (27.8%, 29.2% and 29.7%, respectively...
