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.
Klide AM.Lumbar and thoracic vertebrae of the extinct horse, Equus occidentalis, were examined for gross and radiographic evidence of overriding spinous processes. Of 2,661 vertebrae examined, 580 had intact spinous processes. Thirty-six intact spinous processes, which appeared grossly similar to overriding spinous processes in the modern domestic horse, E caballus caballus, were radiographed. Of these 36 vertebrae, 2 had radiographic signs compatible with a radiographic diagnosis of overriding spinous processes, ie, radiographically observed lysis and/or sclerosis. Seemingly, weight bearing or other s...
Allen D, Swayne D, Belknap JK.The clinical signs, medical and surgical management, and pathological findings are described for a ganglioneuroma, an atypical intestinal tumor, that caused colic because of small intestinal obturation.
Pool RR, Meagher DM, Stover SM.Navicular syndrome is a degenerative disorder of the distal half of the flexor surface of the proximal sesamoid bone that is predisposed by faulty foot conformation. In horses that become symptomatic, the faulty conformation results in sustained application of nonphysiologic pressure by the deep digital flexor tendon against the flexor cortex of the bone. This force stimulates an intense bone remodeling response in order to attenuate the pressure. An unfortunate sequela of this response is active hyperemia and edema formation in the medullary cavity of the bone. The edema is organized by fibro...
Schuh JC.Bilateral true colobomas with retrobulbar cysts located over the optic nerves are described in an 8-year-old Quarterhorse mare with a history of progressive blindness. Colobomas result from the failure of an embryonic fissure to close and retrobulbar cysts result from eversion of the neuroectoderm through the colobomas. It could not be determined whether the small optic nerves and the scars, rosettes and disorganization of the cell layers in the retina were the result of concurrent dysplasia or were secondary to degeneration.
Cox JH, DeBowes RM, Leipold HW.Two cases of congenital malignant melanomas in horses are described in this report. In each case, wide surgical excision of the mass was performed; no recurrence or metastasis was detected after a minimum of 15 months' follow-up. Melanomas are among the most common neoplasms of horses, but they typically develop in gray horses greater than 6 years old.
Steiss JE, White NA, Bowen JM.Electroacupuncture was used to treat lameness in horses and ponies with chronic laminitis (n = 10) or navicular disease (n = 10). A clinical trial was conducted with random allocation of equal numbers of animals to control and treatment groups. Acupuncture was performed three times per week for four consecutive weeks. The degree of lameness was assessed by 1) a grading scheme, 2) measurement of stride lengths and 3) analysis of weight distribution using a force plate. Although seven out of ten animals with chronic laminitis improved clinically during the trial, there were no statistically sign...
Hooper RN.Necropsy of a 12-year-old Quarter Horse mare revealed a blind-end segment of intestine originating from the antimesenteric border of the ileum. The blind-end segment had looped around and strangulated the ileum and 3.5 m of the jejunum.
Geor RJ, Petrie L, Papich MG, Rousseaux C.The effects of sucralfate and ranitidine on the gastrointestinal manifestations of phenylbutazone (PBZ) toxicity in horse foals were determined by complete blood count, serum chemistry profile, and gross and histological necropsy examinations. Twenty-eight, three to four month old Belgian-cross foals were randomly assigned to one of four groups. Phenylbutazone was administered at a dosage of 10 mg/kg of bodyweight (BW) per day, intravenously (IV), in equally divided doses to three of the groups. In addition to PBZ, ranitidine was administered at 2 mg/kg BW, IV, twice daily, to one group of sev...
Engelking LR, Anwer MS, Hofmann AF.The role of bile salt in biliary lipid excretion was studied in 3 healthy ponies with chronic external biliary fistulas. After endogenous bile salt pool depletion, micelle-forming taurocholate or taurochenodeoxycholate was infused to replace excreted bile salt. Enterohepatic circulations were held open (total biliary diversion) throughout each study. Results indicated that biliary lipid excretion in ponies (113 +/- 21 nmol/min/kg of body weight) is approximately 10 times less than that reported in rodents. Although the lipid composition (4.4% cholesterol, 5.6% phospholipid, and 90% bile salt) ...
Shadomy HJ, Dixon DM.An unusual fungus, probably traumatically introduced into the eye of a horse while grazing, was studied on various mycological media. Upon examination of colonies the organism produced bulbils and clearly exhibited the characteristics of a new species of Papulaspora, P. equi Shadomy & Dixon.
de Lahunta A, Hatfield C, Dietz A.An unusual occipitoatlantoaxial malformation is described in a 2-week-old male part Arabian foal that was unable to stand at birth and showed signs of spastic tetraparesis due to a cervical spinal cord compression. There were 2 atlases present. One was fused to the occipital bones. The other articulated with the first atlas and an axis which had a long dens that projected into the vertebral canal. Examination of the ossification centers of the axis indicated partial duplication of that bone.
Bürki F, Nowotny N, Rossmanith W, Pallan C, Möstl K.During 3 foaling seasons around 150 Lipizzaner foals were vaccinated against ERP with commercial vaccines and groups thereof were serotested in CF and SN for their humoral immune response. In addition, 6 horses of cheaper common breeds were vaccinated on the University premises, were continuously serologically screened and subjected to virulent nasal test infection. The live-virus vaccine Prevaccinol interfered so profoundly and up to the 20th week of life with maternal antibodies that its further use was discontinued. The inactivated vaccine Pneumabort-K proved to be of impressive immunogenic...
Dintinger T, Gaillard JL, Zwain I, Bouhamidi R, Silberzahn P.The results of the measurement of 19-nortestosterone in the testiscular artery and vein of the stallion, the very low levels of this steroid in the peripheral blood of geldings and the similar patterns of increase in the peripheral levels of 19-nortestosterone and testosterone after hCG stimulation, show that 19-nortestosterone, like testosterone, is essentially synthesized in the testis. This testicular origin was confirmed by the ability of testicular tissue to synthesize 19-norandrogens from [4-14C]androgens in vitro. 19-Nortestosterone was 50% conjugated in the peripheral blood and almost ...
Hannant D, Jessett DM, O'Neill T, Mumford JA.Serum antibody (IgGab, IgM and IgA) responses to primary and secondary infection with influenza A/equine/Newmarket/79 (H3N8) by nebulised aerosol were compared with local (nasopharyngeal and tracheal) antibody responses in ponies. Circulating IgGab antibody was of long duration after primary infection, whereas IgM responses were short-lived after both primary and secondary infections. The antigenic stimulation of secondary infection with equine influenza was sufficient to induce elevations of serum IgM and IgA in the presence of high levels of circulating IgGab. These results support the poten...
Waelchli RO, Winder NC.The distribution of histopathological lesions in the equine endometrium was examined to investigate the representativeness of a single biopsy specimen in terms of the whole endometrium. Five sections from each of 110 uteri obtained from slaughtered mares were evaluated microscopically and classified according to a four-category grading system used for endometrial biopsies. Depending on the extent of agreement between the categories of the homologous sections, the uteri were considered to show either good agreement (81 uteri; 73.6 per cent), moderate agreement (26 uteri; 23.6 per cent) or poor ...
Auer DE, Ng JC, Thompson HL, Inglis S, Seawright AA.An acute phase reaction was elicited in four horses to which Freund's adjuvant was administered intramuscularly. The localised inflammation was accompanied by changes in the plasma concentrations of copper, iron and zinc. The plasma copper concentration, the plasma ceruloplasmin copper concentration and the ceruloplasmin oxidase activity in the plasma steadily increased to a maximum 24 days after the administration of the adjuvant. At this time, the plasma copper concentration was 2.2 micrograms/ml, a 90 per cent increase over the baseline concentration. The ratio of the concentration of plasm...
Haluska GJ, Wilkins K.Rectal temperature was recorded from 22 mares at 0700, 1500 and 2300 h daily for seven days pre-partum and one day post partum. A circadian variation in rectal temperature was present with the lowest temperature recorded at 0700 h. Because of this, the mares were divided into three groups based on time of parturition; those foaling between 0700 and 1500 h (n = 2); between 1500 and 2300 h (n = 13); and between 2300 and 0700 h (n = 7). On the day prior to delivery (Day -1) the circadian pattern was absent because the nocturnal increase did not occur. A significant decrease in temperature was rec...
Bülow A, Bülow T, Mill J, Dietz O.Painful interventions can be performed on horse in standing position by means of sedative analgesia, also called standing-position anaesthesia. Combinations of anaesthetics are quite often used, in that context, for the purpose of producing analgetic effects stronger and more reliable than those that would be obtainable from one anaesthetic alone. The following combinations were comparatively tested for their analgetic and sedative effects and their effects upon the organism: Chloralhydrate with Ursonarkon (oxazolidone), Chloralhydrate with Rompun (xylazine), Chloralhydrate with morphine hydro...
Beard WL, Robertson JT, Getzy DM.To compare the effects of placing enterotomy incisions on or off the antimesenteric teniae and closing the intestinal mucosa as a separate layer, four longitudinal enterotomies were performed in the descending colon of each of six horses by the following techniques: incision through the antimesenteric teniae with one- and two-layer closure, and incision adjacent to the teniae with one- and two-layer closure. The horses were necropsied at day 33 for evidence of obstruction, adhesions, and ultrasonographic determination of the percent reduction in lumen diameter. Histologic and histomorphometric...
DeBenedette V.Horseback riding carries several risks, some of which can be minimized if riders take riding lessons, wear proper headgear and footgear, and remember that they are on top of a large, willful animal.
Beard WL, Lohse CL, Robertson JT.The blood supply to the descending colon of the horse was studied by gross dissection and methyl methacrylate corrosion casts. The arterial supply is derived from the left colic artery and cranial rectal artery with the left colic artery supplying approximately the proximal three fourths. Each artery gives off four to eight arcuate arteries that form a series of anastomosing arcades. The arcade pattern continues to form a marginal artery that parallels the long axis of the colon. Small branches from the marginal artery anastomose with adjacent branches to form a secondary arcade. The secondary...
Clay CM, Squires EL, Amann RP, Nett TM.Effects of season and photoperiod on the anterior pituitary gland and testes were studied by responses to exogenous GnRH. Stallions were assigned to one of three treatments: 1) control, exposed to natural day length; 2) S-L, 8 h of light and 16 h dark (8:16) for 20 wk beginning July 16, 1982 then 16:8 from December 2, 1982 until March 5, 1984; or 3) S-S, 8:16 from July 16, 1982 until March 5, 1984. Approximately every 8 wk, stallions were administered GnRH (2 micrograms/kg BW) and blood was sampled at 20-min intervals for 2 h before and 8 h after GnRH administration. Concentrations of LH, FSH ...
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.
Wheeler SJ, Plummer JM.Transverse sections of the lateral palmar nerve from a group of horses free from neuromuscular disease were assessed quantitatively, with emphasis on differences in the fibre population related to age. Morphometric analysis of the population of myelinated and unmyelinated fibres was performed. Changes were identified, there being a loss of larger myelinated fibres in older horses. The relationship of myelin thickness to axon diameter and the unmyelinated fibre population did not alter with age. The lateral palmar nerve is suitable for biopsy and electrophysiological study in the horse, but age...
Morris DD, Ward MV, Whitlock RH.Plasma concentrations of plasminogen were determined in 28 clinically normal horses, including 13 adult geldings, five non-pregnant mares, five pregnant mares and five yearlings (two fillies, three geldings). Plasminogen was quantitated by a chromogenic assay based on activation of plasmin by excess urokinase. The overall mean plasma plasminogen for these horses was 2.94 +/- 0.54 CTA units (casein units, as defined by the Committee on Thrombolytic Agents) per ml. There were no significant differences in mean plasma plasminogen values among adult geldings, non-pregnant mares, pregnant mares or ...
Salonen JS, Vähä-Vahe T, Vainio O, Vakkuri O.The pharmacokinetics of detomidine, a novel analgesic sedative, was studied in the major target species after high (80 micrograms/kg) i.v. and i.m. doses. In addition, drug residues in some organs were determined. Concentrations were measured using a sensitive, detomidine-specific radio-immunoassay method. Rapid absorption following i.m. dosing occurred. Absorption half-lives were 0.15 h (horse) and 0.08 h (cattle). The mean peak concentration in the horse (51.3 ng/ml) was achieved in 0.5 h and in the cow (65.8 ng/ml) in 0.26 h. The areas under the concentration curve after i.m. dosing were 66...
Wichtel ME, Buys E, DeLuca J, Stringel G.This article focuses on the pharmacologic properties of drugs commonly used in the treatment of neonatal septicemia and its complications. Rational therapy demands an awareness of not only the pharmacology of individual drugs but also the interactions and anticipated fate of such drugs in the rapidly changing physiologic environment of the neonate. Further research in the area of equine neonatal pharmacology should greatly assist our understanding of the impact of the disease state on the unique physiology of the newborn and should allow us to better predict the ultimate fate of drugs commonly...
Clark ES, Becht JL.This article discusses the various drugs that affect the equine gastrointestinal tract. Drugs that alter intestinal motility, that protect the gastrointestinal tract, and that alter secretions, as well as analgesics, appetite stimulants, and orally administered antimicrobial agents are reviewed.
Lotstra RJ, van den Broek J, Power T, Marr CM, Wijnberg ID.Atrial fibrillation is a common equine arrhythmia. Quinidine alone, or with digoxin are common treatments. Studies on outcome in Warmblood populations in which duration of the AF is often unknown are limited. Objective: To identify the factors that are associated with the success of full treatment cardioversion with oral medication, and establish whether there are differences in these factors between institutions. Methods: Retrospective case series using patient records of Equine University Clinic of Utrecht University and Rossdales Equine Hospital, Newmarket. Methods: Forty-nine horses treate...
Losch K, Heinze W, Mieth K.The formula proposed by RITSCHEL (1973) for calculation of rates of resorption is explained and modified for use of the monocompartment model. Resorption rates were calculated for cattle, calf, horse, and sheep, with reference being made to the example of Mebacid tablets. The most favourable rate of resorption was established for calf.
Solter PF, Farner S.The purpose of this study was to compare 2 different nonradioactive assay methods with a conventional radioimmunoassay (RIA) measuring the concentration of serum thyroxine (T4) in horses. Serum was obtained from 85 adult standardbred horses. The T4 concentration of each sample was analyzed by RIA, chemiluminescent enzyme immunoassay (CEI), and homogeneous enzyme immunoassay (HEI). The correlation between the HEI method and RIA method was significantly greater (r = 0.89) than the correlation between the CEI and the reference method (r = 0.53). In addition, the precision of the HEI method was si...
Gimsing S.Occupational injuries are notifiable in Denmark. Hitherto, occupational injuries caused by riding and horse handling have not been reported. Methods: This retrospective study comprises all cases reported to the National Working Environment Authority during the period 1992-1999. Results: There were 634 occupational accidents, and 43% of the victims were below the age of 25 years with a four-in-one female preponderance. In contrast, there were only three cases of occupational disease. Conclusions: Occupational diseases ought to be much more common than suggested by these few reported cases. Resp...
Gottschalk RD, Reyers F, van den Berg SS.The effects of a commercially available equine hyperimmune anti-endotoxin serum on synovial fluid parameters were evaluated in an induced synovitis model in normal horses. Four groups of 3 horses each received lipopolysaccharide (LPS) plus hyperimmune antiendotoxin (anti-LPS), LPS, anti-LPS, and Ringers lactate (control) respectively injected into the left intercarpal joint. Synovial fluid parameters were measured at 4, 8, 24 and 72 h. It was found that anti-LPS had no attenuating effect on the LPS and that it induced a synovitis almost equivalent to that induced by LPS alone. The introduction...
Rizzo A, Mutinati M, Spedicato M, Minoia G, Trisolini C, Punzi S, Roscino MT, Jirillo F, Sciorsci R.The beta-subunits of thyroid stimulating hormone (TSH) and human chorionic gonadotropin (hCG) share a high homology, just like the ectodomains of their receptors, do. As a consequence, hCG was shown to exert a thyrotropic action in humans and hamsters. This study aimed to investigate whether hCG, used to induce ovulation, displays a thyrotropic effect in the equine species too. Forty mares at estrus were divided in two groups; 20 were intravenously treated with sterile saline solution (NaCl 0.9%) (group A); 20 were intravenously treated with 4000 I.U. of hCG (group B). All the mares were artif...
Knickelbein KE, Lassaline ME, Kim S, Thomasy SM.The iridocorneal angle (ICA) is the major pathway of aqueous humour outflow from the anterior chamber of the eye. Ultrasound biomicroscopy (UBM) has been utilised to characterise the morphology of this drainage pathway in numerous species. UBM may allow for early recognition of aqueous humour outflow obstructions in horses, allowing for earlier recognition of risk for glaucoma, a vision-threatening and painful disease. UBM morphology of the normal equine ICA has yet to be described. Objective: To determine the ultrasonographic morphology of the equine ICA by UBM in standing sedated horses. Met...
Tschudi P.The use of the ECG to separate the different phases of the heart cycle registering other physiological signals, to evaluate the fitness and state of training of a horse and to detect a pregnancy of a mare is reported and illustrated in this text.
Gaschen L, LeRoux A, Trichel J, Riggs L, Bragulla HH, Rademacher N, Rodriguez D.The magnetic resonance (MR) imaging findings of foals with infectious and noninfectious arthritis are described. Six foals with infectious arthritis and three foals with noninfectious arthritis were grouped based on synovial fluid analysis results and examined with radiography and MR imaging. Four out of six foals with infectious arthritis had osseous lesions in MR images indicative of osteomyelitis and only 4/19 lesions were detected on digital radiographs. The three foals with noninfectious arthritis had no osseous lesions in MR images or radiographically. Of the six joints that had osseous ...
Webster WR.This section outlines the most important issues addressed in the management of the response in the two infected states, New South Wales and Queensland. There were differences in the management of the response between the states for logistic, geographic and organisation structural reasons. Issues included the use of control centres, information centres, the problems associated with the lack of trained staff to undertake all the roles, legislative issues, controls of horse movements, the availability of resources for adequate surveillance, the challenges of communication between disparate groups...
al-Timimi I, Gaillard JL, Amri H, Silberzahn P.Whereas mare corpus luteum does not produce androgens or estrogens in vivo, the incubation of mare corpus luteum microsomes with progesterone and NADPH resulted in 17 alpha-hydroxyprogesterone and estrogen production with a small yield of androstenedione. In the presence of an aromatase inhibitor (4-hydroxyandrostenedione), 17 alpha-hydroxyprogesterone and androstenedione were accumulated. Aromatization of testosterone and androstenedione occurred via stereospecific loss of the 1 beta, 2 beta hydrogen atoms and was inhibited by MgCl2, KCl, and EDTA. The Km of estrogen synthetase from equine co...
Greene EA, Smith KR, Pendergraft JS, Raub RH, Arns MJ.When the decision was made to euthanatize an acutely laminitic Thoroughbred broodmare, graduate students from the Department of Animal Sciences and Industry reconstructed the skeleton for use as a teaching tool. The reproductive and gastrointestinal tracts were removed and preserved in formalin. The hide, muscle, tendons, ligaments, and organs were removed, and the bones were boiled in water for > or = 48 h to remove all remaining tissue. After boiling, the bones were soaked in gasoline to remove fat from the marrow cavities and then soaked in a bleach/detergent mixture as a final cleaning ...