Equine health encompasses the study and management of diseases, disorders, and overall well-being of horses. It involves understanding various physiological systems, preventive care, and treatment strategies to maintain optimal health in equine populations. Common areas of focus include nutrition, infectious diseases, orthopedic conditions, and reproductive health. Research in equine health aims to advance knowledge on diagnostic methods, therapeutic interventions, and management practices that improve horse welfare and performance. This page collects peer-reviewed research studies and scholarly articles that explore the diverse aspects of equine health, offering insights into current findings and advancements in the field.
Coryn M, De Morr A, Bouters R, Vandeplassche M.The authors analysed clinical, histological and hormonal data obtained from 205 cryptorchid horses. The majority of the unilaterally and bilaterally retained testes were located in the inguinal canal; however, the ratio of inguinal vs abdominal retention appeared to decrease with advancing age. In unilateral cryptorchidism, a pronounced preference was noted for left abdominal retention, whereas for inguinal cryptorchids, the retained testes occurred equally on both sides. Right inguinal retention was found to decrease with advancing age. Histology of cryptorchid testes revealed apparently norm...
Snow DH, Douglas TA, Thompson H, Parkins JJ, Holmes PH.Toxic effects of phenylbutazone (PBZ) in ponies and horses were studied, using a variety of biochemical, pathophysiologic, and pathologic methods. At dosage levels of 10 to 12 mg/kg of body weight/day for 8 to 10 days, ponies frequently developed clinical signs of toxicosis characterized by hypoproteinemia. Studies using 51CrCl3 demonstrated that PBZ caused a protein-losing gastroenteropathy. The plasma loss was usually associated with gastrointestinal ulceration, but sometimes occurred without obvious lesions in mildly affected animals. Similar studies (8.2 mg/kg/day for 13 days) in Thoroughb...
Baker CB, Newton DI, Mather EC, Oxender WD.The length of diestrus was not changed in 4 mares by taking endometrial biopsy specimens during estrus. In contrast, taking endometrial biopsy specimens on postovulation day 4 induced premature luteolysis and significantly (P less than 0.05) reduced the length of diestrus. A concurrent decrease in serum progesterone occurred to verify the premature luteolysis in these mares. Bacterial cultures of endometrial swab samples from these mares were negative for growth at the first estrus before and after the last biopsy procedures, indicating that luteolysis was induced by the biopsy procedure and w...
Stover SM, Brown MP, Kelly RH, Farver TB.Six healthy adult mares were given a single dose (25 mg/kg of body weight) of sodium oxacillin IM. Oxacillin concentrations in serum, synovial fluid, peritoneal fluid, and urine were measured serially over a 48-hour period. The mean peak serum oxacillin concentration was 9.75 microgram/ml at 0.5 hour after injection. Mean peak oxacillin concentrations in synovial and peritoneal fluids were 1.45 microgram/ml and 2.60 microgram/ml at 1 hour and 2 hours, respectively. These concentrations decreased in parallel with serum values and were not measurable at 48 hours. Urine concentrations of oxacilli...
Wells PW, McBeath DG, Eyre P, Hanna CJ.This article attempts to relate some of the more recently accepted concepts of immunology to an understanding of the mechanisms of immunity in the horse. The cellular mechanisms involved in the immune response are outlined, with an indication of their likely role in humoral and cell-mediated immunity. In describing the humoral immune response, the structure and function of the different equine immunoglobulins are reviewed. The significance of humoral and cell-mediated immune responses are considered in relation to actively and passively acquired immunity.
Salama SA, Dardiri AH, Awad FI, Soliman AM, Amin MM.African horsesickness virus was isolated from blood samples of street dogs in Aswan Province in Arab Republic of Egypt. Of six isolated "dog strain" African horsesickness viruses, three viruses designated D2, D6 and D10 have been identified as type 9 African horsesickness virus. Methods of isolation, tissue culture adaptation, serological indentification and typing are described. Horses experimentally infected with dog viruses showed febrile reaction and characteristic clinical and pathological signs of African horsesickness. Reisolation of African horsesickness virus type 9 was achieved from ...
Moens Y, De Moor A.The carbon dioxide content of respiratory gases may be monitored by the use of an infra-red carbon dioxide analyser. The technique allows continuous and non-invasive recording of important information concerning the ventilatory, circulatory and metabolic states of the anaesthetised horse. Some of the monitoring capabilities of a carbon dioxide analyser (capnograph) are reviewed with illustrations from cases anaesthetised in the authors' clinic. Technical faults in the anaesthetic apparatus and the connections with the "patient" could be readily detected and emergency situations immediately rec...
Persson SG, Ullberg LE.Blood volume and parameters of body size were studied in 45 Standardbred foals during their first 400 days of life. Bodily dimensions, including body weight (bwt), depth of chest, girth and length (distance from point of shoulder to caudal aspect of croup), increased curvilinearly with age. There was a much faster growth rate noted for the first 100 days of life. Bwt could be predicted from girth and length much more precisely than from age alone. The total blood volume increased proportionately with age and, consequently, the plasma and red cell volumes as functions of bwt were high at birth ...
Moore JN, Garner HE, Coffman JR.Experimental carbohydrate overload of 15 horses resulted in consistent haematological changes during development of laminitis hypertension. Significant alterations in packed cell volume, leucocyte differential count, serum glucose levels and protein values occurred before onset of Obel grade 3 lameness and hyperkinetic circulatory state. Blood platelets were significantly decreased 8 h after the onset of severe lameness. Findings in this study were indicative of haemoconcentration due to compartmental fluid shifts and leucocytic stress response consistent with increased circulating adrenogluco...
Henry RW, Diesem CD.Radial and median motor nerve conduction velocities were determined on 10 clinically healthy 1- to 11-year-old ponies. These velocities were obtained by stimulation at the brachial plexus directly through a surgical incision and later in the ambulatory pony via implanted Formvar-coated wire electrodes. Percutaneous stimulation was used at the cubital region in both anesthetized and ambulatory ponies. The values for radial motor nerve fibers ranged from 96.4 to 100 m/s. These were 15.3% faster than previously reported distal values. Median motor nerve fiber values ranged from 86.8 to 90.2 m/s, ...
Haynes PF.Persistent dorsal displacement of the soft palate was diagnosed in 2 Thoroughbred horses examined because of decreased exercise tolerance and a respiratory noise during strenuous exercise. The persistent dorsal displacement of the soft palate was caused by an epiglottis that was approximately 2/3 normal size, and thus was incapable of maintaining the soft palate in a normal subepiglottic position. Contrast pharyngography suggested a primary epiglottic abnormality. Visual assessment of the lesion was accomplished by exploratory ventral laryngotomy and endoscopy of the oropharynx per os. Surgica...
Doyle A, Owen LN.Sixteen cytotoxic drugs used in cancer chemotherapy in man were studied for cytopathic effect on equine fibrosarcoma, melanoma and normal equine lung cells in vitro. Three drugs, vincristine, melphalan and methotrexate, produced cytopathic effect
Raphel CF, Gunson DE.Percutaneous lung biopsies with a cutting needle (Vim Tru Cut) were obtained from 20 horses. The procedure was performed in standing horses under a local anesthesia without sedation. All lung tissue specimens were suitable for histologic examinations and contained both pulmonary parenchyma and large airways. The only complication was hemoptysis in 2 (10%) horses which required no therapy. All horses were subsequently killed, and no gross abnormalities were present at the biopsy site.
Pascoe RR, Summers PM.The results of a retrospective survey of tumours and tumour-like lesions encountered in horses in a veterinary practice in south east Queensland between 1956 and 1978 are presented. Forty-two per cent of the lesions were examined histologically. The most commonly occurring neoplasms were the equine sarcoid, papilloma and squamous cell carcinoma of the eye and external genitalia. Neurofibroma was an important problem in the eyelid region. Intra-abdominal tumours were rarely encountered in this series.
Smith WN.A system using a suitably sized flotation tank has been developed to reduce the weight that horses and cattle place upon their legs after undergoing surgery to their limbs. The system overcomes the need for the patient to lie down for long periods, thus preventing decubitus. The system is well tolerated with few side effects; after prolonged flotation alopecia may occur on those parts of the patient which remain continuously immersed in water. The method is now commonly referred to as the 'Queensland Sling'.
Tainturier DJ, Delmas CF, Dabernat HJ.Seventeen strains of haemophilus equigenitalis isolated from the cervix, clitoris, and urethra of mares were biochemically characterized with the API 10E and APIZYM test kit systems, conventional biochemical tests, and the porphyrin test. Antisera were prepared in rabbits. All of the strains were positive to the porphyrin test, and the requirement for factor X (hemin) or V (nicotinamide adenine dinucleotide) was not shown. Catalase, oxidase, phosphatase, and phosphoamidase tests were positive with all of the strains. Aminopeptidase (arylamidase) activity has been detected on beta-naphthylamide...
Chacon-Arellano JT, Woolley DM.Smooth muscle cells are present in the tunica albuginea testis of the horse, pig and sheep. typical fusiform muscle cells constitute a distinct layer up to 0.3 micrometer thick in the horse; there are fewer muscle cells, mainly of the branched form, in the pig; whereas in the sheep the muscle component is least well developed, with some cells intermediate in form between smooth muscle cells and fibroblasts (myofibroblasts). Attention is drawn to the continuity of this capsular muscle with the smooth muscle associated with the vasculature of the spermatic cord in the horse. This association sug...
Sassot LN, Ragle CA, Farnsworth KD, Heaton K, Jones ARE.Two mares, aged 15 and 21 years, were examined because of urinary incontinence, intermittent hematuria, and urine scalding. On admission of both horses, physical parameters were within normal limits and urine scalding of the skin at the ventral perineum was noted. Transrectal palpation and cystoscopy revealed a large type I cystolith (>10 cm) with associated hyperemia and focal ulceration of the bladder mucosa. In horse 1, hemogram, serum biochemical analysis, and renal ultrasound were not performed because of owner finances. In horse 2, results from hematological and serum biochemical analys...
Hunt JP, Haywood PE, Moss MS.A gas chromatographic screening procedure for the non-steroidal anti-inflammatory group of drugs is described. The method invovles on-column methylation of the carboxylic acid group using trimethylanilinium hydroxide as the methylating reagent. Fifteen such drugs were studied. Eight of these were detected in urine collected from horses that had received these compounds orally and for these drugs, rates of urinary excretion are recorded. Seven other members of this group of drugs were shown to be detectable by this procedure but in these cases the drug was added to urine and not administered to...
Singh AK, Mishra U, Ashraf M, Abdennebi EH, Granley K, Dombrovskis D, Hewetson D, Stowe CM.Chemical ionization- and electron impact ionization-selective ion monitoring provided a simple and sensitive method for measuring detomidine (Domosedan), a potent sedative-analgesic drug for horses and cattle. Chemical ionization was at least 10 times more sensitive than electron impact ionization. By using propranolol as an internal standard, we found that the recovery of detomidine from the extraction procedure used in this study was greater than 75% for plasma, whole blood, or urine samples. Approximately 68% of detomidine was bound to plasma protein and 53% was bound to red blood cells.
Holden-Douilly L, Pourcelot P, Chateau H, Falala S, Crevier-Denoix N.This article describes a method that allows estimating, with the 2D version of the direct linear transformation (DLT), the actual 2D coordinates of a point when the latter is not strictly in the calibration plane. Markers placed in vertical line, above, below and in the centre of a horizontal calibration plane were filmed by a moving camera. Without correction, strong errors (up to 64.5%) were noticed for markers out of the calibration plane. After correction, calculated coordinates were consistent with actual values (error < 0.55%). The method was then applied to slip distance measuremen...
Al-Dissi A.A wide variety of toxins cause diseases in the horse and are investigated routinely by veterinarians and veterinary pathologists to identify the cause of illness and death. A complete investigation involves performing a thorough necropsy and requires macroscopic and microscopic examination of lesions and a variety of laboratory testing to obtain an accurate diagnosis. The identification of gross lesions by equine practitioners is often the first step in formulating a diagnostic plan. This article provides a description of selected common toxins producing detectable gross lesions in horses in N...
Harrington DD.Acute accidental vitamin D2 (ergocalciferol) toxicosis was diagnosed in a 6-month-old foal with extensive lesions of soft tissue mineralization. In an experimental study, three 18-month-old horses were given ergocalciferol per os at a rate of 9,300, 22,200, or 47,200 IU/kg of body weight/day for 21 days. Clinical signs or lesions were not seen in horses given the low and intermediate doses, whereas the horse receiving the highest dose developed clinical signs and lesions similar to those noted in the foal. Signs included depression, loss of appetite, weakness, limb stiffness with impaired mobi...
Stiglhuber A, Breit S, König HE.The equine fetlock joint cavity shows ten pouches. The dorsal recess, which is oriented to the proximal side, is separated from those three pouches, which show to the distal direction, by several capsular folds. These folds are documented by means of sagittal sections through the fetlock joint. A medial/lateral recess is covered by the deep part of the collateral ligament of the fetlock joint. The collateral ligaments as well as the sesamoidean collateral ligaments are closely connected with the joint capsule, from which two capsular folds are separated. Between the part of the sesamoidean col...
Monzon CM, Jara GA, Hoyos CB.The usefulness of the direct agglutination test (DA) to diagnose Mal de Caderas disease was evaluated. Forty four sera samples from two lots of horses with natural T. evansi infection (Lot 1 and Lot 2) were used. Thirteen (81.2%) of sixteen horses in which parasites were isolated gave positive agglutination titres (> or = 1:512) in the DA test. Treatment of these positive sera with 2-mercaptoethanol drops three to eight dilutions the agglutination titres in twelve samples (92%), showing the IgM nature of these antibodies. The DA test was also positive in seventeen of twenty eight horses in ...
Lehner AF, Almeida P, Jacobs J, Harkins JD, Karpiesiuk W, Woods WE, Dirikolu L, Bosken JM, Carter WG, Boyles J, Holtz C, Heller T, Nattrass C....Remifentanil (4-methoxycarbonyl-4-[(1-oxopropyl)phenylamino]-1-piperidinepropionic acid methyl ester) is a mu-opioid receptor agonist with considerable abuse potential in racing horses. The identification of its major equine urinary metabolite, 4-methoxycarbonyl-4-[(1-oxopropyl)phenylamino]-1-piperidinepropionic+ ++ acid, an ester hydrolysis product of remifentanil is reported. Administration of remifentanil HCl (5 mg, intravenous) produced clear-cut locomotor responses, establishing the clinical efficacy of this dose. ELISA analysis of postadministration urine samples readily detected fentany...
Apprich V, Spergser J, Rosengarten R, Stanek C.The effects of two dermatophytes (Microsporum gypseum and Trichophyton mentagrophytes) and four moulds (Scopulariopsis brevicaulis, Alternaria alternata, Geotrichum candidum and Penicillium spp.) on living keratinocyte cultures were examined in vitro using primary human keratinocytes. Rates of apoptosis of infected cells were determined using a colorimetric TUNEL system which detects the characteristic nuclear DNA fragmentation of apoptotic cells. The cytotoxicity of the individual fungi was tested by quantitatively measuring cytosolic enzyme lactate dehydrogenase, released upon cell lysis, in...
Sim RR, Padilla LR, Joyner PH, Anikis P, Aitken-Palmer C.Anaplasma phagocytophilum (formerly Ehrlichia equi ) is a tickborne pathogen of domestic horses and the causative agent of equine granulocytic anaplasmosis. After the occurrence of clinical anaplasmosis in a Przewalski's horse ( Equus ferus przewalskii) housed at the Smithsonian Conservation Biology Institute in 2008, opportunistic serosurveillance of the herd was initiated. From 2008 to 2014, 57 serum samples were collected from 27 individuals (10 males; 17 females). Using indirect immunofluorescent antibody assays for anti- Anaplasma phagocytophilum antibodies, it was determined that prevale...
Timoney JF.An R antigen of the group C streptococcus S. equi that cross reacts with a similar antigen of S. zooepidemicus has been identified and characterized. It is acid, heat and trypsin resistant, but pepsin sensitive and has an isoelectric point of 4.8. The amino acids in highest concentration are glutamic, aspartic, alanine, leucine, and valine. Bacterial components released in a French Press contain large amounts of R antigen, which is present also in culture supernatants and acid extracts. It has a molecular weight of about 82,000. Trypsin extraction of cells yields molecules of predominantly 56,...
Miller PJ, Holmes JR.Systolic time intervals (STIs), isovolumic contraction time (ICT) and left ventricular ejection time (LVET) were recorded from seven horses with supraventricular arrhythmia. The STIs were measured over a number of beats (33 to 100) directly from the left ventricular (LV) and aortic (Ao) pressure contours which were recorded simultaneously using two catheter-mounted transducers. ICT was significantly (P less than 0.01) and directly related to beat-by-beat heart rate (HR = 60/pulse interval) and LVET was significantly (P less than 0.01) and inversely related to heart rate in each of five horses....
Welles EG, Prasse KW, Duncan A, Morris MJ.An antigenic assay was developed for determination of protein C in horses. Protein C, a natural, vitamin K-dependent anticoagulant component in blood, was isolated from equine plasma, a specific antibody was produced in goats, and a rocket electroimmunophoresis assay was established. Tests were performed to verify the identity of the isolated protein C and to determine the purity of the antibody. Protein C antigen was measured in plasma from 34 clinically normal horses, and values were compared with amidolytic function values. The mean (+/- SD) values for the 2 test methods were similar (antig...
Al-Wabel NA.Semicarbazide-sensitive amine oxidase (SSAO) activity was measured spectrophotometrically using benzylamine as a substrate, in the serum of healthy males and females of horses, camels, cattle, sheep and goats. The animals were born and raised in the same area, and the blood collection was made on the same day to avoid variations. Also the concentrations of protein and copper were measured in the same samples. There were no significant gender-related differences in SSAO activity between the tested animals regardless of species. Activities of SSAO in either male or female of horse were significa...
