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.
Cudd TA, LeBlanc M, Silver M, Norman W, Madison J, Keller-Wood M, Wood CE.Fetal maturation and the timing of parturition in both sheep and primates are thought to be controlled by the hypothalamic-pituitary-adrenal axis but little is known about the endocrinology of the equine fetus. We investigated the ontogeny of plasma concentrations of adrenocorticotropic hormone (ACTH), cortisol and corticosteroid binding capacity in the late-gestation fetal horse. We also wished to determine whether there is ultradian rhythmic release of ACTH and cortisol in fetal horses and we compared fetuses to maternal and non-pregnant adult horses. Six fetuses, 278-304 days gestation (ter...
Fey K, Klatt P, Schmidt H, Sasse HH.Five healthy horses were given a sulfadoxine/trimethoprim combination (Borgal, Hoechst AG) i.v. on day 1. The next ten days the horses got once a day a sulfadimethoxine/trimethoprim combination orally (Trafigal, Hoechst AG). The doses were given as recommended. One horse received no medicaments for control. On each horse six bronchoalveolar lavages were performed. Blood samples were taken to calculate blood levels and elimination half lives. To determine the amount of substances in lavage fluid and plasma the high performance liquid chromatography (HPLC) was used. Regularly low quantities of s...
Kakoi H, Gawahara H, Miura N.An unusual D system phenogroup appeared in one family line of Anglo-Arab horse. This phenogroup probably originated from inheritance with an apparent absence of factors and was transmitted through successive generations.
Gomez-Villamandos R, Santisteban J, Ruiz I, Avila I.Two horses with fibrotic myopathy of the semitendinosus muscle are described. The report deals with the aetiology, clinical signs and diagnosis of the condition, and discusses the different surgical techniques described in the literature. Tenotomies were performed on both horses. Excellent results were obtained in the horse in which only the semitendinosus muscle was affected, but in the horse in which the semimembranosus and gracilis muscles were also involved the results were less satisfactory.
Duyn RJ, van Haeringen H.Hyperkalaemic periodic paralysis is a genetic disease that affects the American Quarter Horse population and is caused by a mutation. As a result of this mutation in a gene which codes for the sodium channel in muscle cells, severe muscle weakness can appear. Reliable DNA-tests can establish whether a horse is homozygous negative, heterozygous, or homozygous positive for this mutation. Therapy and prevention are discussed.
Barnes HG, Tucker RL, Grant BD, Roberts GD, Prades M.A traumatic fracture of C2 was diagnosed radiographically in a 1-year-old German Warm-blood stallion. Fracture configuration was difficult to see on survey radiographs. Computed tomography yielded a more accurate assessment of the fracture and facilitated fracture repair with cortical lag screws. Precise screw placement, to avoid spinal cord damage, was obtained by use of computed tomography. Follow-up radiography revealed normal bone healing, and the horse was in dressage schooling 24 months after surgery.
Guglick MA, MacAllister CG, Chandra AM, Edwards WC, Qualls CW, Stephens DH.Mercury toxicosis by ingestion was diagnosed in a 3-year-old Quarter Horse mare with a history of anorexia and signs of abdominal discomfort. Ten and 9 days prior to admission, an inorganic mercuric blistering agent has been applied for topical treatment of dorsal metacarpal disease. At referral, signs of depression, dependent edema, pollakiuria, nonproductive cough, and oral ulceration were noticed. Laboratory data were consistent with renal dysfunction. Mercury content of blood and urine was high, confirming the diagnosis. The horse responded to intensive care, consisting primarily of IV flu...
Chaffin MK, Honnas CM, Crabill MR, Schneiter HL, Brumbaugh GW, Briner RP.A 4-month-old male Quarter Horse was referred for evaluation of urinary incontinence. Physical examination revealed clinical signs consistent with cauda equina syndrome. Radiography revealed diskospondylitis of S2 through S4. Infected bone was surgically curretted, and drainage was established for an associated paravertebral abscess. Rhodococcus equi was isolated from specimens of bone and from fluid samples obtained from the paravertebral abscess. Bethanechol was administered to stimulate urination. Erythromycin and rifampin were administered for 120 days. The foal's neurologic dysfunction re...
McCartan CG, Russell MM, Wood JL, Mumford JA.An outbreak of equine herpesvirus-1 (EHV-1) occurred on a large stud farm with 133 mares, 54 foals and four stallions, and at least 85 mares, 22 foals and three stallions were infected. Clinical disease was observed in 16 mares, two stallions and 13 foals and the predominant clinical signs were scrotal oedema, ataxia and loss of libido in the stallions, ataxia and recumbency in the mares and uveitis and nasal discharge in the foals, although pneumonia and colic with intussusception were also recorded at autopsy. Neurological disease was more common in the mares nursing foals (12 of 38 infected...
Sutton RH, Coleman GT.Abstract Extract A 15-year-old pony mare developed firm irregular bony swellings on all four legs. These were most severe around the carpal and fetlock joints of the forelegs, restricting both flexion and extension. Over about 6 months the horse had periodic bouts of coughing. She showed moderate weight loss and a depressed demeanour.
Edwards RB, Fubini SL.Five Holstein calves and two foals with omphalophlebitis were treated by surgical marsupialization of the umbilical vein remnant because complete resection of the infected tract was not possible. The infected umbilical stalk was resected, and the umbilical vein remnant was marsupialized in a one-stage procedure by suturing it into the abdominal wall lateral to the abdominal incision. Antimicrobial drugs were administered, and the marsupialized tract was irrigated until closure by second intention healing. Cellulitis associated with the marsupialization site occurred in two calves but resolved ...
Navarro P, Barbis DP, Antczak D, Butler JE.The cDNA from a transcript encoding the complete heavy chain of the equine immunoglobulin IgE has been cloned and sequenced. A fragment of the equine epsilon gene was amplified from cDNA using PCR and this fragment was then used to probe a horse cDNA library prepared from peripheral blood lymphocytes. A recombinant clone containing the cDNA encoding the complete horse epsilon chain and its associated V-D-J and leader, was subsequently isolated and sequenced. Comparison of the deduced amino acid sequence of equine IgE with the C epsilon heavy chains of other species indicates it to be most simi...
Widders PR, Warner S, Huntington PJ.Normal mares were immunised by the intramuscular and intrauterine administration of an antigen with adjuvant and they and unimmunised control mares were later challenged by the intrauterine instillation of pathogenic Streptococcus zooepidemicus; the response of all the mares was monitored clinically and bacteriologically for seven days. Significantly fewer S zooepidemicus were present in cervical swabs taken from the immunised mares than from the control mares (P < 0.01) and the degree of inflammation in the genital tract of the immunised mares was also significantly less (P < 0.001). Th...
Adeyefa CA, Hamblin C.Equine sera collected from 10 widely separated regions throughout Nigeria were tested for antibodies against African horse sickness viruses (AHSV) using a competitive enzyme-linked immunosorbent assay (ELISA). The animals sampled included imported, exotic horses, indigenous and locally cross-bred (local) horses and African donkeys. A high percentage of the sera (79.8%) were positive, confirming the continued prevalence of AHSV antibodies in Nigerian horses and donkeys.
Zweygarth E, Just MC, de Waal DT.The protozoan parasite Babesia equi, a causative agent of equine piroplasmosis, was continuously cultivated in horse erythrocytes. The parasites were isolated from a carrier horse at a time when no parasite was detected in a thin blood smear. The culture medium consisted of modified medium 199 supplemented with 40% non-heat-inactivated horse serum in a humidified atmosphere containing 5% CO2, 2% O2, and 93% N2 at 37 degrees C. Parasites were detected after 2 days in culture. When the percentage of parasitized erythrocytes (PPE) reached 1%, the cultures were transferred into a humidified atmosp...
von Rotz A, Friess AE.Sinus hairs, which are tactile organs of most mammals, are differentiated into cavernous and sinus types. The horse has the cavernous type. Horse lower lips were perfused in diluted Karnovsky's fixative and sinus hair processed for scanning electron microscopy. Anastomosing trabeculae of different thickness and shape originate from the internal connective tissue layer and extend to the external layer, thus forming a dense meshwork suspending the hair root like a net. However, many of the distal trabeculae do not reach the external wall of the blood sinus but end in a finger-like knob within th...
van der Kolk JH, Wensing T, Kalsbeek HC, Breukink HJ.The objective of the study was to determine the sensitivity with which an adenoma of the pars intermedia of the pituitary gland can be predicted in horses by measuring the basal concentrations of glucose, cortisol, adrenocorticotropin (ACTH), and insulin, the urinary concentration of corticoids, the urinary corticoid:creatinine ratio, and the plasma cortisol concentration after the administration of 25 IU of ACTH intravenously. The records of 24 cases of histologically confirmed equine pituitary pars intermedia adenomas were used. An adenoma of the pars intermedia of the pituitary gland in hor...
Guthrie AJ, Beadle RE, Bateman RD, White CE.The purpose of this study was to characterize the normal equine tidal breathing flow-volume loop (TBFVL). The study was performed using 18 healthy Thoroughbred horses. TBFVLs constructed from data collected from resting horses had a typical biphasic inspiratory and expiratory phase. The interindividual variability of the indices used to describe TBFVLs was in the range 16-32%, which is comparable to the variability of other measures of equine pulmonary mechanics. The large variability of these data probably limits the value of resting TBFVL indices for detecting subclinical respiratory conditi...
Pailhoux E, Cribiu EP, Parma P, Cotinot C.In this study, cytogenetic analysis of an infertile mare revealed a 64, XY karyotype. The XY sex-reversed animal had a female phenotype with gonadal dysgenesis. Using Southern blot analysis, we tested for the presence of two Y-specific genes SRY and ZFY by using DNA isolated from peripheral blood leukocytes. The results showed that at least the DNA-binding domain of the SRY gene was deleted from the Y chromosome of the XY mare but that the ZFY gene was present on this chromosome.
Messer NT, Johnson PJ, Refsal KR, Nachreiner RF, Ganjam VK, Krause GF.Six healthy, adult horses, with normal (mean +/- SEM) baseline serum concentrations of total triiodothyronine (T3, 1.02 +/- 0.16 nmol/L), free T3 (FT3, 2.05 +/- 0.33 pmol/L), total thyroxine (T4, 19.87 +/- 1.74 nmol/L), free T4 (FT4, 11.55 +/- 0.70 pmol/L), total reverse T3 (rT3, 0.68 +/- 0.06 nmol/L), and cortisol (152.75 +/- 17.50 nmol/L), were judged to be euthyroid on the basis of response to a standardized thyroid-stimulating hormone response test. Serum concentrations of T3, FT3, T4, FT4, rT3, and cortisol were determined immediately before and every 24 hours during a 4-day period of foo...
Bracher V, Steiger R, Huser S.In the present study the breath hydrogen (H2) excretion test was combined with the xylose absorption test in 4 normal horses and 9 clinical patients with chronic diarrhea (n = 3) or chronic weight loss without diarrhea (n = 6). All horses underwent a thorough clinical examination. Laboratory evaluations consisted of haematology and serum biochemistry as well as bacteriological and parasitological examination of feces. In addition, serum electrophoresis and abdominocentesis was performed in all the clinical patients. Gastroscopy was carried out in 6 patients and rectal biopsies were obtained fr...
Chen CL, Goldberg J, Gronwall RR.A radioimmunoassay was developed for prednisolone using IgG purified from rabbit antiserum. The assay was employed to determine the pharmacokinetics of prednisolone following intravenous administration of 450 mg of prednisolone sodium succinate (Solu Delta Cortef) to five adult Thoroughbred horses. The RIA had a sensitivity of 2 ng/ml and was relatively specific. It had cross-reactivity with 21-deoxycortisol (83.3%) cortisol (27.8%), 11-beta-hydroxyprogesterone (39.2%) and 17-hydroxyprogesterone (50%). However, it did not cross-react with naturally occurring steroids (cholesterol, testosterone...
Sticker LS, Thompson DL, Bunting LD, Fernandez JM, DePew CL.Sixteen light horse mares (8 to 9 yr of age; 457 to 579 kg BW) were fed Bermudagrass hay and a corn/cottonseed hull-based supplement formulated to contain either 100% (control) or 50% (restricted) of the protein and(or) energy requirements for maintenance in a 2 x 2 factorial arrangement of treatments. Daily measurements of intake, BW, and plasma hormones and metabolites were made for 33 d. Plasma glucose, insulin, NEFA, and urea N were measured in hourly samples drawn on d 27, and parallel with an i.v. glucose tolerance test (IVGTT) and epinephrine challenge on d 29. Energy restriction increa...
Parente EJ, Nunamaker DM.Six forelimb specimens from three adult horses had the fetlock joint fused by application of a dorsal plate and by a screw placed in lag fashion through the metacarpus to each proximal sesamoid bone. Five specimens were instrumented on the central dorsal surface of the plate with a single rosette strain gage, and the plate of the sixth specimen was instrumented with four longitudinally oriented single-axis strain gages. The specimens were loaded axially in compression to 4,000 N in a cast (test 1), in a cast with a heel block (test 2), and uncast (test 3). The principal angle of strain in all ...
Back W, Schamhardt HC, Savelberg HH, van den Bogert AJ, Bruin G, Hartman W, Barneveld A.The kinematics of 24 two-year-old Dutch Warmblood horses were recorded at the trot (4 m/s) on a high-speed treadmill to study the coordination of joints within the equine forelimb. Joint angle-time, angle-angle, stick, and marker diagrams were used to show forelimb motion graphically. Because the kinematic data referred to the joint angles of the horse standing squarely and were time-standardised to the duration of the stride cycle, mean joint curves could be calculated for the total group. The motion of each segment in the equine forelimb during a complete stride is described and its function...
Gånheim A, Gånheim A, Jöchle W.In a blinded trial, the effectiveness and safety of 2.2 mg of the GnRH analog deslorelin acetate, administered in a short-term implant (STI) to normally cycling mares in estrus with a dominant ovarian follicle of 30 mm in diameter or larger, were evaluated, using a placebo implant as a negative control. A total of 39 mares received treatments at admittance with pre-randomized implants containing either 2.2 mg or 0 mg deslorelin. Mares were teased daily and examined rectally with ultrasound at 24 h intervals to determine time to ovulation and duration of estrus. The number of breedings and the ...
Beadle RE, Guthrie AJ, Kou AH.A density-corrected ultrasonic pneumotachometer designed specifically for horses (UF202) was evaluated and characterized with the aid of a custom-built apparatus. UF202 provided voltage outputs for airflow through and gas density within the flowhead. Baseline stability for flow channel output (VUF202) was or = 0.9976). Under optimal conditions, VUF202 accuracy was determined to be +/- 1.00% FS and repeatability was +/- 0.78% FS. VUF202 resolution was 24 ml/s. The rise time for VUF202 was 18 ms, and the -3-dB point was 18 Hz; digital compensation provided a flat frequency response to 32 Hz. VU...
Darien BJ, Potempa J, Moore JN, Travis J.Antithrombin-III (AT-III) activity was measured at the time of admission in 46 horses referred with colic. Differences in AT-III activities between animals treated medically or surgically and survivors or non-survivors were compared. The mean AT-III values for the horses treated medically (76.2 per cent), surgical survivors (69.5 per cent) and surgical non-survivors (55.9 per cent) were significantly different from the reference value for healthy adults (92 to 108 per cent). The mean AT-III activity of the survivors was significantly (P less than 0.01) greater than that of the nonsurvivors. Th...
Laus F, Rossi G, Paggi E, Bordicchia M, Fratini M, Tesei B.Tumors involving the oral cavity of the horse are uncommon. No cases of equine adenocarcinoma on the dorsum of the tongue have been reported in the literature. We report a case of adenocarcinoma located on the dorsum of the posterior one-third of the tongue in a 29-year-old gelding with severe dysphagia. Endoscopy revealed an epiglottis involvement, and histology was consistent with adenocarcinoma arising from minor salivary glands, which was associated with a severe fungal colonization of affected tissues. The goals of this report are to present an uncommon case of dorsum of the tongue-associ...
Mellor DJ.Physiological challenges facing the perinatal individual are huge. This is partly because of the marked and abrupt change from the intrauterine to the extrauterine environment, but also because the physiological responses to that change depend upon systems whose maturation is affected markedly by birth. Perinatal maturation appears, therefore, both to precede and accompany the physiological adaptations required for neonatal survival. This review does not provide a comprehensive coverage of perinatal physiology but directs attention towards evaluating constraints on foetal and neonatal thermoge...
Salem M, El-Shafaey ES, Farag AMM, El-Khodery S, Al Mohamad Z, Abass M.This study was conducted to establish a detailed anatomic reference for the carpal joint of apparently healthy donkeys using ultrasonography (US), computed tomographic (CT), and magnetic resonance imaging (MRI). Ten orthopedically sound adult donkeys were used for US examination of the carpal joint in each forelimb. Additionally, the carpi of ten donkey cadavers were subjected to CT and MRI examinations. The carpal joint was divided into four zones to simplify examination. US assessment of the carpal joint included transverse and longitudinal sonograms. CT was performed using three planes: axi...
McCue PM, Freeman DE, Donawick WJ.From 1977 to 1986, guttural pouch tympany was diagnosed in 15 horses--11 fillies and 4 colts. Review of the medical records provided results of physical, microbiologic, radiographic, and endoscopic examinations, treatment protocols, complications, and recovery rate. All affected horses had visible swelling in the parotid gland region, 9 had abnormal respiratory noise, 5 had pneumonia, and 1 had dysphagia. Six horses were treated by median septum fenestration alone, and in 8 horses, this procedure was combined with resection of the mucosal flap at the pharyngeal orifice of the eustachian tube. ...
Swardson CJ, Lichtenstein DL, Wang S, Montelaro RC, Kociba GJ.To characterize infection of bone marrow-derived macrophages (BMDM) with equine infectious anemia virus (EIAV) by determining virus production, effects on viability, and induction of cytokines. Methods: BMDM obtained from bone marrow of 6 clinically normal adult horses. Methods: BMDM were infected with EIAV at a multiplicity of infection of 8. Cell viability, percentage of cells with detectable viral protein, reverse transcriptase activity, and concentrations of infective virus (focus-forming units/ml), interleukin 6, and tumor necrosis factor-alpha were measured in culture supernatant samples...
Mizobe F, Wakuno A, Okada J, Otsuka T, Ishikawa Y, Kurimoto S.A total of 20 racehorses with longitudinal fractures underwent internal fixation surgery under sevoflurane anesthesia combined with infusion of medetomidine (3 µg/kg/hr) alone (10 horses, group M) or medetomidine and fentanyl (7 µg/kg/hr) (10 horses, group FM). In group FM, the end-tidal sevoflurane concentration during surgery was maintained significantly lower than in group M (2.8-2.9% for group M vs. 2.2-2.6% for group FM, P<0.01). The mean arterial blood pressure was maintained over 70 mmHg using dobutamine infusion (group M, 0.36-0.54 µg/kg/min; group FM, 0.27-0.65 µg/kg/min), and ...
Williams DO, Boatwright RB, Rugh KS, Ross CR, Sarazan RD, Garner HE, Griggs DM.Adult-grade ponies were surgically instrumented with a Doppler flow probe and pneumatic cuff occluder on the left anterior descending coronary artery (LAD), sonomicrometry crystals and intraventricular micromanometer in the left ventricle, and catheters in the left atrium, anterior interventricular vein, and, in some animals, the LAD. Conscious-animal studies were begun 2 wk after surgery. Measured variables included regional left ventricular systolic function, end-diastolic wall thickness, oxygen extraction, lactate extraction, and hydrogen ion release. Changes in collateral perfusion were de...
van den Berg MJ, Rijkenhuizen AB, Németh F, Gruys E.Chronic changes of several structures in around the fetlock tunnel can be a cause of the so-called fetlock tunnel syndrome (FTS) in the horse. Forty-nine annular ligaments (AL) from dead horses without a known history or clinical evidence of lameness and/or digital tendon sheath problems in these legs and 30 AL biopsies from horses suffering from FTS were studied macroscopically and microscopically. Macroscopically, the normal AL had a shiny white appearance, whereas the affected AL were often thicker and less white. Microscopically, the normal AL were about +/- 1 mm thick and were composed of...
D'Souza-Anjo M, Christensen BW, Brabender K, Zimmermann W, Kass PH, Schwarzenberger F.The aim of this study was to determine whether concentrations of reproductive steroid hormone metabolites significantly differed between harem stallions and bachelor stallions in the free ranging group of Przewalski's horses (Equus ferus przewalskii) at the Hortobágy National Park in Hungary. Throughout the study, fecal samples were collected from 21 harem stallions and 15 bachelor stallions and analyzed for immunoreactive estrogen and androgen metabolites. Harem stallions demonstrated significantly higher concentrations of estrogen (P < 0.001) and epi-androsterone (P < 0.001), ...
Edinger H, Miller I, Stanek C, Gemeiner M.The spectrum of serum proteins was evaluated in 46 horses affected with spontaneous laminitis and correlations between the severity of the disease and changes of the protein pattern were analyzed. The investigation was made in two groups; group A consisted of 21 horses of various breeds (warmblood, thoroughbred, standardbred) and group B of 25 ponys. Each group was subdivided according to the severity of the disease, using the OBEL-grade (OG) classification system. Serum proteins were separated by different one- and two-dimensional electrophoretic methods. Sera analysed by cellulose acetate el...
Honnas CM, Schumacher J, Cohen ND, Watkins JP, Taylor TS.The medical records of 25 horses with septic tenosynovitis treated over 7 years (1983 to 1989) were reviewed to determine clinical features of the disease and response to treatment. The median age of horses with septic tenosynovitis was 5 years (range, 1 month to 21 years). Fourteen fore limbs and 11 hind limbs were affected. Sepsis was located in the sheath of the digital flexor tendons of 22 horses. Sepsis was located in the sheath of the extensor carpi radialis tendon (1 horse), sheath of the long digital extensor tendon (1 horse), or sheath of the common digital extensor tendon (1 horse) i...
Barr AC, Reagor JC.Horses poisoned by a plant may show a myriad of clinical signs. Awareness of the poisonous plants growing in a given area and those that are likely to appear in hay and their associated clinical signs can be instrumental in making diagnoses. More importantly, the information can be shared with clients to help prevent plant poisonings in horses.
Slivinska K.A diagnostic deworming of 21 Przewalski horses, free-living in the Chernobyl exclusion zone Ukraine, and of six stabled domestic horses, has been conducted eighteen years after the Chernobyl nuclear disaster. This survey yielded 31 species (of 5 families and 3 classes, 28 species of nematodes, 1 species of cestodes, and 2 larvae of botflies). A total 29 and 19 helmith species has been recorded in the Przewalski horse and domestic horse respectively. Only six helmith species were common for the two horse species. Species from the family Strongylidae constituted the dominant helmith group. Four ...
Pemberton AD, McEuen AR, Scudamore CL.Mast cell proteinases are important inflammatory mediators in man and other species, but until now there has been no investigation of the nature of equine mast cell proteinases. These studies describe the purification and characterisation of two proteolytic components from equine mastocytoma tissue, detected using chromogenic substrates for trypsin and chymotrypsin. Following chromatographic purification, the trypsin-like component was found to be equine mast cell tryptase by N-terminal amino acid sequencing, showing a close similarity with human tryptase-beta (85% identity over 20 residues). ...
Nocera I, Aliboni B, Ben David L, Gracia-Calvo LA, Sgorbini M, Citi S. Laminitis is a debilitating disorder resulting in irreversible anatomical changes in the feet of equids. Assessing specific anatomical features through radiography and venography provides diagnostic and prognostic information. The reference ranges are well-established in horses, but not in donkeys. It is also uncertain as to whether these ranges can be applied to every donkey breed. The present study characterizes the radiological and venographic hoof anatomy of healthy feet of Amiata donkeys and defines the changes associated with severe and mild laminitis. A total of 16 forefeet were evalu...
Mantovani A, Caporale V, Ciuchini F, Di Trani L, Irsara A, Prosperi S.The results of antibody titrations in different animal species vaccinated against rabies are reported. The following points are considered: (1) antibody titration may be used to detect an immunity status in dogs, (2) equines should be vaccinated in infected areas, (3) experiments in progress are comparing ERA vaccine and an inactivated vaccine in bovines, and (4) the vaccination of fallow deer (Dama dama) and moufflons (Ovis ammon musimon) produced results suggesting an extension of the experiment with the purpose of vaccinating wild ruminants whenever possible.
Kooistra LH, Ginther OJ.At day 24 of gestation, pregnant mares were allotted to 1 of 5 treatment groups (3 to 5 mares/group): group A--nontreated controls; group B--intraembryonic injection of 4 mg of colchicine on day 24; group C--removal of embryo on day 24; group D--subcutaneous injection of 1.25 mg of prostaglandin F2alpha (PGF2alpha) on day 32; and group E--removal of embryo on day 24 and subcutaneous injection of PGF2alpha on day 32. In all mares treated with colchicine (group B), the fetal bulge was absent within 2 days. The interval from injection of colchicine to onset of estrus was very short (mean, 4 days)...
Beaumier PM, Fenwick JD, Stevenson AJ, Weber MP, Young LM.Plasma and urinary levels of salicylic acid were examined in Standardbred mares after administration of various feeds, containing different compositions of hay. In addition, horses were administered acetylsalicylic acid orally and methyl salicylate topically. Elevated salicylic acid levels were observed in horse urine and plasma in animals fed lucerne hay. The plasma and urinary elimination of salicylic acid exhibited a diurnal pattern which was related to the type of feed and the feeding schedule. Within 24 h after oral administration of acetylsalicylic acid, plasma and urine salicylic acid l...