"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.
Little PB.A review of 6 cases of equine cerebrospinal nematodiasis diagnosed between 1958 and 1971 indicated that 2 major clinical syndromes occur—chronic incoordination and an acute progressive fatal encephalitic disease. The gross lesions of acute cases occur most commonly in the centrum ovale and the cerebellar roof nuclear region and appear as hemorrhagic serpentine tracks. The invariable existence of endocardial or proximal aortic verminous lesions caused by Strongylus vulgaris in horses with verminous encephalitis circumstantially incriminates S. vulgaris parasitic emboli as the most common caus...
Walton TE, Alvarez O, Buckwalter RM, Johnson KM.Ten horses (Equus caballus) were vaccinated with strain TC-83 Venezuelan equine encephalomyelitis (VEE) virus vaccine. Febrile responses and leukopenia due to a reduction of lymphocytes and neutrophils were observed in all animals. Viremias were demonstrable in eight horses, with a maximum of 10(3.5) median tissue culture infectious dose units per ml of serum in two horses. Clinical illness with depression and anorexia were observed in five horses. Neutralizing (N), hemagglutination-inhibiting, and complement-fixing antibodies to the vaccine virus were demonstrable by 5, 6.5, and 7 days, respe...
Else RW, Holmes JR.The normal histology of cardiac tissues has been described by many authors, for example Gross and Kugel (1931), Trautmann and Fiebiger (1952), Gould (1968), Bloom and Fawcett (1969) and Ham (1969). In the horse, a few reports have described microscopic valvular pathology in detail (Ackerknecht 1923, Imre 1933, Ubach and Cler 1944). Experimentally induced lesions have been reported by Wadsworth (1919), Wadsworth and Sickles (1927) and Miller (1944), and endocarditis was described by Winqvist (1945) and Dobin (1959, 1968).
In 1966, Smetzer, Bishop and Smith outlined the valvular pathology ass...
French DA.Equine practitioners are frequently called to attend to soft tissue injuries. The majority of these cases are routine and straightforward; however, a certain percentage may present as a life-threatening situation with potentially serious complications. Client communication, adequate preparation, patient stabilization, accurate injury assessment and appropriate wound preparation are key factors to expedite recovery and achieve a favorable outcome. Understanding the limitations of field therapy and deciding when to transport the case to a clinic or referral center plays an important role in the ...
Yee S, Peyton DH.The redistribution of the initially-formed myoglobin heme-insertion isomers from the initially formed 50/50 mixture to the equilibrium ratio of 90/10 has long been assumed to occur by one of two mechanisms, both of which require the rupture of the heme iron-protein bond (La Mar, G.N., Toi, H. and Krishnamoorthi, K. (1984) J. Am. Chem. Soc. 106, 6395-6401). In this study we compared the use of nuclear magnetic resonance and optical spectroscopic techniques as methods for studying the reorientation of heme within myoglobin. We found that kinetics determinations of the heme insertion isomer redis...
Taylor EL, Sellon DC, Wardrop KJ, Hines MT, Kingston JK.To assess safety and determine effects of IV administration of formaldehyde on hemostatic variables in healthy horses. Methods: 7 healthy adult horses. Methods: Clinical signs and results of CBC, serum biochemical analyses, and coagulation testing including template bleeding time (TBT) and activated clotting time (ACT) were compared in horses given a dose of 0.37% formaldehyde or lactated Ringer's solution (LRS), IV, in a 2-way crossover design. In a subsequent experiment, horses received an infusion of 0.74% formaldehyde or LRS. In another experiment, horses were treated with aspirin to impai...
Schwarzwald CC, Bonagura JD, Luis-Fuentes V.Quinidine is effective for treatment of atrial fibrillation (AF) in horses, but often accelerates ventricular response rate. Diltiazem effectively controls heart rate response to AF in other species. This investigation determined the effects of diltiazem on cardiac rate and rhythm, left ventricular (LV) function, central hemodynamics, and peripheral blood flow in normal, standing, nonsedated horses. A dose-finding study was performed. Afterward, 8 healthy horses were treated with diltiazem IV every 30 minutes to achieve cumulative dosages of 0 (saline control), 1, 1.5, and 2 mg/kg. Plasma dilt...
Hellyer PW, Dodam JR, Light GS.Dynamic baroreflex sensitivity for increasing arterial pressure (DBSI) was used to quantitatively assess the effects of anesthesia on the heart rate/arterial pressure relationship during rapid (less than or equal to 2 minutes) pressure changes in the horse. Anesthesia was induced with IV administration of xylazine and ketamine and maintained with halothane at a constant end-tidal concentration of 1.1 to 1.2% (1.25 to 1.3 minimal alveolar concentration). Systolic arterial pressure (SAP) was increased a minimum of 30 mm of Hg in response to an IV bolus injection of phenylephrine HCl. Linear regr...
Bauer C, Bürger HJ.A paste formulation containing 14.3 per cent of oxibendazole and 44 per cent of trichlorfon was administered to 33 ponies and horses. The dose rate used was equivalent to 10 mg and 30 mg/kg bodyweight, of oxibendazole and trichlorfon respectively. After treatment 25 animals passed between one and 82 third stage larvae of Gasterophilus intestinalis in their faeces. Dosing with 0.2 mg ivermectin/kg bodyweight three weeks later resulted in six animals expelling between one and four bots. The efficacy of the oxibendazole-trichlorfon paste was on average 96.2 per cent. This drug combination given t...
Soana S, Gnudi G, Bertoni G, Botti P.The aim of this study is to point out the time of appearance of the carpal and tarsal bones in the fetal horse, considering an estimated fetal age, to follow their morphological development through to birth, and to characterize possible abnormal shape and/or delay of their ossification. The right carpal and tarsal region of 140 equine fetuses of both sexes (71 males, 69 females) and different ages (from 70 to 340 days of gestation) were examined radiographically in order to identify the sites of ossification from their earliest appearance. The times of appearance of the sites of ossification o...
Millward LM, Hamberg A, Mathews J, Machado-Parrula C, Premanandan C, Hurcombe SD, Radin MJ, Wellman ML.A 6-year-old female Rocky Mountain horse was presented for evaluation of draining tracts and distal limb subcutaneous edema on the left front and left hind limbs that had been present for 2 weeks. Direct smears of fluid collected by fine-needle aspiration of subcutaneous fluid from both limbs were highly cellular with a predominance of eosinophils accompanied by numerous, moderately atypical, variably granulated mast cells. The cytologic diagnosis was mast cell tumor (MCT) with prominent eosinophilic infiltration with a differential diagnosis of eosinophilic granuloma. Histologic evaluation of...
Edwards GB, Vaughan LC.Six horses were found to have infective arthritis of one elbow joint. The history, and presence of a small wound on the lateral aspect of the elbow suggested the condition was trauma induced. Two horses recovered following joint lavage under general anaesthesia and antibiotic therapy. The joint changes found post mortem in the others were characteristic of an infective arthritis.
Testa B, Biggi M, Byrne CA, Bell A.Acquisition of magnetic resonance images of the equine limb is still sometimes conducted under general anaesthesia. Despite low-field systems allow the use of standard anaesthetic equipment, possible interferences of the extensive electronic componentry of advanced anaesthetic machines on image quality is unknown. This prospective, blinded, cadaver study investigated the effects of seven standardised conditions (Tafonius positioned as in clinical cases, Tafonius on the boundaries of the controlled area, anaesthetic monitoring only, Mallard anaesthetic machine, Bird ventilator, complete electro...
Hargis AM, Clark EG, Duclos DD, Leclerc S, West K.Over a 6-year period seven adult horses of different breeds and genders developed multifocal, exudative, oozing dermatitis characterized histologically by epidermal spongiotic vesicles and perivascular eosinophilic, neutrophilic and mixed mononuclear inflammation. Three horses were pruritic. Systemic disease was not noted. Two horses had a history of recurrent urticaria (hives) and one horse had nodules or welt-type lesions that progressed to exudative, oozing lesions. Interepithelial immunoglobulin (Ig)G was detected by avidin-biotin complex-peroxidase staining, but the pattern of staining wa...
Zynda HM, Scare JA, Steuer AE, Anderson HP, Nielsen MK.Cyathostomins are pervasive equine parasites in horses across the world, and larval stages are known to cause the deadly disease larval cyathostominosis. The mucosal digestion technique is widely used for enumeration of encysted larval stages. Previous studies have investigated the spatial variation of encysted larvae, however current protocols lack a description of a standardized area from which to take the tissue sample. This study sought to evaluate spatial variation in encysted cyathostomin larval counts among the large intestinal organs and their subsections. Following humane euthanasia, ...
Nishita T, Matsushita H.Sections of equine thymus were examined for the presence of carbonic anhydrase (CA) isozymes by an immunohistochemical method. Carbonic anhydrase III, a major enzyme of skeletal muscle, was localized in some of the epithelial-reticular cells of the equine thymus. This finding suggests the presence of a new type of cell in the thymic cortex. The concentration of CA-III in the thymus was 17 micrograms/g wet tissue. CA-I and CA-II were not found in equine thymus.
van der Kolk JH, Wisse H, van Dijk S.A 20-year-old Arab crossbred gelding was examined because it had apparently suffered an overstimulation of the parasympathetic nervous system for three hours. The clinical signs consisted of hypersalivation, profuse sweating, maximal miosis, fasciculation of the muscles and lateral recumbency in combination with continuous convulsions without diarrhoea. The horse's plasma pseudocholinesterase activity was approximately 10 per cent of normal. It responded well to 10 mg atropine and 50 mg diazepam administered intravenously.
