"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.
Augustinsson KB, Bartfai T, Mannervik B.The steady-state kinetics of the butyrylcholinesterase-catalysed hydrolysis of butyrylthiocholine and thiophenyl acetate were shown to deviate from Michaelis-Menten kinetics. The ;best' empirical rate law was selected by fitting different rate equations to the experimental data by non-linear regression methods. The results were analysed in view of two alternative interpretations: (1) the reaction is catalysed by a mixture of enzymes, or (2) the activity is due to a single enzyme displaying deviations from Michaelis-Menten kinetics. It was concluded that the second alternative applies, and this...
Nakajima H, Yoshino T, Ushimi C.Equine infectious anemia virus was purified from infected horse serum samples. Electron microscope observation on negatively stained preparations of purified virus showed roughly spherical particles sized between 100 and 200 nm in diameter. In disrupted particles, an envelope was visible but no internal structure could be resolved. Since the purified virus fraction had a strong antigenic activity to antiserum in immunodiffusion reaction, these particles are thought to be the causative virus of equine infectious anemia.
Van Der Vekens N, Hunter I, Timm A, Decloedt A, De Clercq D, Deprez P, Goetze JP, van Loon G.Equine atrial natriuretic peptide (ANP) plasma concentrations are correlated with left atrial size. However, species-specific assays are lacking and the results from human assays are poorly reproducible. A new methodology called processing independent analysis (PIA) that measures the total proANP product in plasma has proven to be successful in human medicine, but has never been used in horses. The aims were to establish an equine proANP reference interval by measurement of the total proANP product using PIA and to examine the proANP concentrations in horses with atrial dilatation. Sample stab...
Fritsch R, Hausmann R.In 26 horses measurings of blood pressure, using the Dinamap 1255 research monitor, were performed and compared for accuracy with blood pressure values obtained by direct measurement in the arteria carotis. It was found that oscillometrically ascertained initial blood values in standing horses have a sufficient correlation to initial blood pressure values obtained by direct measurement. But every blood pressure change is registered too late, when using the oscillometric blood pressure apparatus. This temporal delay becomes unacceptable, when a considerable increase in blood pressure occurs. A ...
Auer DE, Ng JC, Seawright AA.Polymorphonuclear leukocytes (PMNLs) were isolated from an inflammatory exudate induced in the intercarpal joints of horses by an administration of carrageenin. Their superoxide production at rest and following stimulation with either serum-treated zymosan (STZ) or phorbol myristate acetate (PMA) was measured by cytochrome-c reduction. Stimulation of the cells increased the cytochrome-c reduction 10-15 times that of resting cells. The maxima were 20 nmol of reduced cytochrome-c per 10(6) cells per ml at 120 min (STZ) and 35 nmol of reduced cytochrome-c per 10(6) cells per ml at 60 min (PMA). T...
May-Davis S, Doveren A, Sweere R, Smak J, Vermeulen Z.Hereditary multiple exostoses (HME) is a condition rarely diagnosed in horses, which has not been previously reported in Dutch Warmblood horses. Its presentation resembles that diagnosed in humans, and it is predominantly active during periods of skeletal maturation. This case study reports a link between a granddam with no obvious HME lesions and its first and second generations presenting with HME, albeit with different sires. The severity in affected horses (n = 5) varied from one foreleg to the other with extensive multiple lesions of 123 of 205 bones in a half sibling in the first genera...
Tsuzuki N, Seo JP, Haneda S, Yamada K, Furuoka H, Tabata Y, Sasaki N.A 13-month-old Thoroughbred filly was diagnosed with osteochondritis dissecans (OCD) of the medial tibial malleolus. A sponge impregnated with platelet-rich plasma, bone morphogenetic protein-2, mesenchymal stem cells and gelatin β-tricalcium phosphate was applied to the OCD site following arthroscopy and debridement. Postoperative radiography (every week for 16 weeks), computed tomography (CT) (16 weeks postoperatively), arthroscopy (16 weeks postoperatively) and biopsy of the regenerated tissue (16 weeks postoperatively) were performed to evaluate the outcome. Radiographically, the defect b...
van den Hoven R, Meijer AE, Wensing T, Breukink HJ.Gluteal muscle specimens were taken from 4 horses. From 1 of the 4 gluteal muscles, serial sections were prepared. Individual muscle fibers were identified and studied, using photomicrographs of sections stained by different enzyme histochemical methods. In specimens in which cytoplasmic soluble enzymes were studied, use was made of the semi-permeable membrane technique to hamper enzyme diffusion into reaction fluids. Enzymes involved in glycogenolysis, glycolysis, the tricarboxylic acid cycle, synthesis of reduced nicotinamide adenine dinucleotide phosphate, the pentose phosphate cycle, the a...
Cavasin JP, Miller AD, Duhamel GE.An 8-year-old Anglo-European gelding with progressive neurological signs was humanely destroyed and submitted for necropsy examination. The right parietal cortex was disrupted by a well-demarcated, intraparenchymal, 1.5 cm diameter, tan, homogeneous, dense mass. Microscopical examination was consistent with an astrocytoma, which was confirmed on the basis of strong immunohistochemical labelling for glial fibrillary acidic protein. The neoplastic population lacked immunolabelling for oligodendrocyte transcription factor 2. Labelling for ionized calcium binding adaptor molecule 1 highlighted la...
Clarke CJ, Roeder PL, Dixon PM.A severe, advanced case of nutritional osteodystrophia fibrosa is described in a 10-year-old gelding with primary upper respiratory obstruction and chronic weight loss, which was one of a group of similarly affected horses in Ethiopia. The diagnosis was based on the clinical signs, gross lesions, histopathology and management history. The affected bones had suffered severe mineral depletion.
Hauspie S, Martens A, Declercq J, Busoni V, Vanderperren K, van Bree H, Saunders JH.To describe the radiographic appearance of the dorsoproximal aspect of the sagittal ridge of the third metacarpal/metatarsal bone in Warmblood horses. Methods: The lateromedial radiographic projections of the metacarpo-/metatarsophalangeal joints performed on horses as a part of stallion selection were used. The dorsal aspect of the distal third metacarpal/metatarsal bone was divided in two areas. The appearance of the bone surface in area I was classified as normal, irregular, notch, indentation and lucency. For area II, the categories were normal, irregular, depression or lucency and flatten...
Muttini A, Petrizzi L, Tinti A, Bertoluzza A.An investigation was carried out on most common synovial fluid parameters of normal and osteochondritic hocks of horses less than 12 months old in order to confirm the presence of an inflammatory process. Furthermore, a spectroscopic study was performed on synovial fluid from both normal and diseased hocks. A depolymerization of hyaluronic acid was demonstrated in synovial fluid from diseases joints, similar to that reported in human rheumatoid arthritis. A one month rest seem to normalize all parameters considered and in one joint, a return to normal infrared spectrum was demonstrated.
Smith RF, Jackson LS, Moore A.An 125I radioimmunoassay to determine the pattern of urinary excretion of etorphine (a semisynthetic opiate agonist) after its administration to horses is described. Three thoroughbred horses were each given 5, 15, 30 and 100 micrograms of etorphine intramuscularly. Urine was collected for up to 72 after administration. The maximum etorphine concentration after administration of a dose of 5 micrograms was 711 pg ml-1 (concentrations were greater than 100 pg ml-1 after 23 h in all three horses); a 15 micrograms gave 2661 pg ml-1 (levels remained above 100 pg ml-1 for more than 44 h in each hors...
Dyson S.The carpus and metacarpus of 40 horses which were free from lameness and 40 horses with lameness associated with the metacarpophalangeal joint or more distal limb were examined radiographically (Group A). The opacity of the proximal third of the third metacarpal bone was regular, with a uniform trabecular pattern. Osseous cyst-like lesions (OCLLs) were identified in the radial carpal bone (1), the ulnar carpal bone (2), the second carpal bone (15) and the fourth carpal bone (1). Thirty-one of 638 horses (4.8 percent) with forelimb lameness had pain localised to the proximal metacarpal region u...
da Silva TRO, Gonçalves PNC, Marcus VB, Mucellini CI, Dos Santos IR, Kommers G, Driemeier D, Flores EF, Cargnelutti JF, Flores MM.For approximately one decade, a novel papillomavirus termed Equus caballus papillomavirus-2 (EcPV-2) has been associated with equine penile/preputial papillomas and squamous cell carcinomas (SCCs). It is currently believed that the virus has a carcinogenic activity, being able to induce such neoplastic lesions. After being first described, EcPV-2 has been detected in many countries from North America, Europe, and Asia; however, to date, it has not been reported in Brazil. The aim of this research was to investigate the presence of EcPV-2 in penile/preputial papillomas and SCCs of Brazilian hor...
Guthrie AJ, Nichas E, Viljoen FV, Hartmann AM, Killeen VM.A case of sustained supraventricular tachycardia of unknown aetiology in a two-year-old Thoroughbred filly is reported. The cardiac dysrhythm was successfully treated by the oral administration of quinidine sulphate. Conversion of the dysrhythm to sinus rhythm occurred approximately 80 min after the initial dose of 5 g of quinidine sulphate. The horse returned to training approximately 2 months after treatment and has since successfully returned to racing.
French jockeys suffer more severe injuries when they fall off their horses than their British counterparts. While it has been shown that jockeys suffer high rates of fatal and non-fatal injuries, little is known about differences in injury rates between countries. To investigate this, researchers from Australia, France and the UK used prospectively collected data on the rates of fatal and non-fatal injuries in flat and jump jockeys in France and compared them with data from the UK.
Kirker-Head CA, Kerwin PJ, Steckel RR, Rubin CT.Liquid metal strain gauges (LMSG) were implanted surgically at three locations on the intact linea alba (LA) in eight horses. LA strain, strain rate, change in strain and stress were recorded during general anaesthesia, recovery from anaesthesia, standing, vocalisation, rectal palpation and at the walk, trot and canter. LA stress was quantitated using an in vitro tensiometric technique. Stress-strain responses differed significantly (P < 0.05) with location, but each described a characteristic relationship for viscoelastic tissues. Maximum peak stress, peak strain and change in strain occurred...
Raz T, Carley S, Card C.The objective was to compare the effects of eFSH and deslorelin treatment regimes on ovarian stimulation and embryo production of donor mares in early spring transition. Starting January 30th, mares kept under ambient light were examined by transrectal ultrasonography. When a follicle > or =25 mm was detected, mares were assigned to one of two treatment groups, using a sequential alternating treatment design. In the eFSH group, mares (n=18) were treated twice daily with eFSH (12.5mg im) until they achieved a follicle > or =35 mm; hCG was given 36 h later. In the deslorelin group, mares (n=18) ...
Brown J, Physick-Sheard P, Greer A, Poljak Z.Horse movements are one of the most important factors for the spread of equine diseases, and past epidemics indicate that contact networks play an important role. Network analysis was used to describe the spatial and temporal characteristics of horse movements between Standardbred racetracks in Canada and the United States during 2019, and to characterize the network to provide a better understanding of the potential racetrack-to-racetrack spread of infectious disease within the network. Networks were constructed and analyzed as an overall network (the entire study period) and monthly networks...
