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.
Steiner JV, Rendano VT.An aneurysmal bone cyst was diagnosed in the distal metaphysis of Mt3 in a 9-month-old-Quarter Horse colt. The lesion developed between the fifth and ninth month of life and clinically appeared as a non-painful swelling which did not cause a lameness. Radiographs of the lesion showed expansion of the cortex and incomplete septa of new bone extending from the cortex into surrounding soft tissue. Surgical intervention revealed a blood filled cavity. The animal died during the immediate post-surgical period. Histopathologic evaluation of the lesion was performed.
Oltner R, Edqvist LE.Progesterone concentrations in heparinized plasma harvested immediately after blood collection were compared with levels obtained after storage of the corresponding whole blood for 2 h, 4 h, 6 h, 1 day, 2 days and 5 days at room temperature and in a refrigerator. The blood was taken during the luteal phase from 4 dogs, 4 horses, 4 pigs and 8 cows. For 4 cows the storage time was extended to 9 and 20 days. No significant effect of whole blood storage time on plasma progesterone concentrations could be shown for dogs or pigs. For the horse a slight but significant decrease was demonstrated when ...
Liu IK, Shivers CA.Cross-reactivity tests indicated that the equine zona pellucida shares common antigen(s) with porcine zona. Porcine oocytes were therefore used to test for the presence of zona antibodies in the sera of horses. Serum samples were collected from 65 mares infertile for unexplained causes: 7 mares were strongly positive for antibodies reactive to porcine zona pellucida as determined by an indirect immunofluorescence method. Of these 7 mares, aged 8-23 years, 2 were nulliparous and 5 were multiparous. Zona-covered horse oocytes were treated with sera from 4 mares previously identified as zona posi...
Brown MP, Stover SM, Kelly RH, Farver TB.Six adult mares were given a single dose of ampicillin trihydrate (250 mg/ml) intramuscularly at a dosage of 20 mg/kg body weight. Serum, synovial fluid, peritoneal fluid and urine ampicillin concentrations were measured serially over a 48 h period. The mean peak serum ampicillin concentration was 2.49 micrograms/ml at 6 h. Ampicillin was found in synovial fluid and peritoneal fluid, which obtained mean peak ampicillin concentrations of 1.65 micrograms/ml and 1.81 micrograms/ml at 6 h and 4 h respectively. These concentrations declined in parallel with serum concentrations and were still detec...
Seamans KW, Sharp DC.Follicular aromatase activity during sexual resurgence after the winter anoestrus was investigated in 3 groups of 5 Pony mares. Group ET was studied during the early transition period, Group LT in late transition and Group C in full breeding condition. Granulosa and theca cells were incubated for 3 h with 3H-labelled androstenedione or progesterone. Analysis of the free oestrogenic products was by high performance liquid chromatography (HPLC) and recrystallization revealed highly variable oestrogen production in both cell types from mares in all 3 groups. Only oestrone and oestradiol peaks wer...
Grubaugh W, Sharp DC, Berglund LA, McDowell KJ, Kilmer DM, Peck LS, Seamans KW.When mares were pinealectomized in summer or in winter there was no difference in the annual ovulation date of these animals and of pineal-intact controls during the first post-operative breeding season but in the second season the ovulation date of the winter pinealectomized mares was significantly delayed, suggesting a long-term but clear pineal involvement in seasonal reproductive patterns. Exposure of pinealectomized mares to a stimulatory photoperiod failed to advance the average date of first annual ovulation and was similar to that of intact mares receiving no stimulatory lighting. The ...
Kydd J, Miller J, Antczak DF, Allen WR.The maternal immunological response to the developing equine fetus was investigated in 69 pregnancies of various genotypes. In normal intraspecies horse pregnancy (N = 16), 94% of mares produced strong cytotoxic antibody responses to paternal histocompatibility antigens which were first detectable between 44 and 70 days after ovulation. In all other types of pregnancy examined (intraspecies donkey, N = 19; interspecies mule, N = 6; interspecies hinny, N = 2; extraspecies horse-in-donkey, N = 3; and extraspecies donkey-in-horse, N = 21), antibody production was observed less frequently, and som...
Goto H, Shimizu K, Taya Y, Noda H, Tokunaga T.The antibody responses to equine influenza viruses were investigated during a postepizootic period of the disease. Serum samples were collected from a total of 128 horses on three occasions during the years 1967-77. No significant increase of hemagglutination-inhibition antibody titers to subtypes 1 and 2 of equine influenza virus were detected in any of the sera tested. The maternal hemagglutination-inhibition antibody titers of foals decreased over a four month interval. A marked increase of the titers was recognized in only the equine influenza virus vaccinated horses. These findings sugges...
Douglas RH.The number of successful embryo recoveries was 56.0% in experimental mares with no history of breeding problems but in barren mares only 34.3% of embryo recovery attempts were successful. When a recovery attempt was successful, the incidence of twin embryos was 10.7% in experimental mares and 16.7% in barren mares. Maintenance of embryos in vitro for greater than 6 h before non-surgical transfer significantly reduced pregnancy rates compared to maintenance for less than 3 h. The pregnancy rate in recipients at 100 days after ovulation was lower (P less than 0.05) than those at 24 and 30 days a...
Rossdale PD, Silver M, Ellis L, Frauenfelder H.The changes in plasma cortisol concentration in the immediate postnatal period were examined in 3 groups of newborn foals and the response of the adrenal cortex to exogenous ACTH1-24 (tetracosactrin) was tested in 2 of these groups. In full-term Thoroughbred and Pony foals a rise in plasma cortisol occurred between 0 and 30 min after birth, whereas no significant cortisol changes could be detected within 2 h of birth in the group of prematurely delivered foals. These differences in plasma cortisol between term and premature foals were accompanied by differences in blood pH and lymphocyte and n...
Wagner AE, Bennett DG.Eighteen clinically normal horses were used to study the characteristics of normal thoracic fluid. Thoracic fluid was obtained from each horse and was found to be similar to equine abdominal fluid. Total leukocytes averaged 3994/ul, total protein 1.8 g/dl, and specific gravity 1.015. Analysis of thoracic fluid from 16 horses with clinical signs of thoracic disease showed abnormalities in every case. Thoracic fluid analysis alone determined a specific diagnosis in 50% of the cases.
Glade MJ, Krook L, Schryver HF, Hintz HF.Pony foals were injected intramuscularly with 0, 0.5, or 5.0 mg dexamethasone per 100 kg body weight daily for up to 11 months. True absorption of dietary calcium was inhibited by treatment at 18 days (57% versus 14% of intake; P less than .01) and 10 months (72% versus 55% versus 43%: P less than .01), but not at 2 or 7 months, and was independent of age and treatment related decreases in intestinal calcium binding protein activities. Uninary excretion of calcium was increased by treatment through 7 months but decreased at 10 months. Treatment for 18 days resulted in total calcium excretions ...
Saltiel A, Calderon A, Garcia N, Hurley DP.Ovarian activity, as measured by the presence of small (10-15 mm diam.), medium (15-30 mm) and large (greater than 30 mm) follicles, corpora haemorrhagica and corpora lutea (CL), was determined in a total of 3584 ovaries during 1 year using post-mortem specimens. There were significant correlations of the incidence of ovulated follicles (ovulations), large and medium follicles (P less than 0 . 001) and of the mean number of small follicles (P less than 0 . 05) per mare with respect to season. The yearly averages of ovulated, large and medium follicles were 30 . 1, 13 . 9 and 73 . 9%, respectiv...
Sweasey D, Patterson DS, Leadon DP.The lipid content of spinal cord, expressed as a percentage of adult values, was considerably higher for newborn foals than for several other species and traces of esterified cholesterol (type A) were only rarely present in horse fetal cord (from 270 days gestational age onwards). This suggested that, at birth, the spinal cord is neurochemically more 'mature' in the horse than in cattle, sheep and pigs. Data for premature foals revealed no lipid abnormality suggestive of myelin immaturity or degeneration.
Pascoe PJ.A 16 year old Thoroughbred mare was presented to the Ontario Veterinary College because of an acute episode of colic. An exploratory laparotomy was performed and a neurofibroma was identified and successfully removed from the small colon. The clinical and pathological features of this case are discussed.
Rathelot J, Canioni P, Bosc-Bierne I, Sarda L, Kamoun A, Kaptein R, Cozzone PJ.Porcine and equine colipases have been submitted to mild tryptic digestion. Proteolysis occurs at the Arg5-Gly6 bond with the loss of the N-terminal pentapeptide. Studies of native and trypsin-treated colipases by circular dichroism and laser chemically induced dynamic nuclear polarization indicate that proteolysis induces conformational changes in the region of the tyrosine cluster. Experiments in the presence of phospholipid provide further evidence showing that these residues are in or close to the region of the protein interacting with aggregated lipids. Kinetic studies of the reaction of ...
Crowhurst FA, Dickinson G, Burrows R.An outbreak of paresis occurred on a small isolated stud farm in July 1980. Of the 42 horses on the stud, infection was confined to a group of nine in-foal mares and their foals and eight other horses which were either housed together at night or grazed adjacent pastures. Eight mares and two geldings developed ataxia or paresis and one mare died. Equid herpesvirus 1 was isolated from 17 animals and serological studies confirmed that 24 of 26 animals sampled had experienced infection.
Ott EA, Asquith RL, Feaster JP.Forty-six Thoroughbred and Quarter Horse yearlings were used in two experiments designed to determine the amount of lysine in the concentrate necessary to promote maximum growth when fed the Coastal bermudagrass (Cynodon dactylon) hay provided at 1% body weight (BW)/day. In the first experiment, a 196-day trial, supplemental protein sources and analyses of the concentrates compared were: (1) soybean meal (SBM; 15.4% crude protein, .70% lysine); (2) SBM + .2% lysine (15.7% crude protein, .81% lysine), and (3) brewers dried grains + .2% lysine (15.9% crude protein, .59% lysine). Concentrate inta...
Yu YY, Xu MS, Liang H, Wang HY, Yu CQ, Liu Q.Despite over 40 years of research on the human immunodeficiency virus type 1 (HIV-1) vaccine, we still lack a considerable progress. Equine infectious anemia virus (EIAV) is a lentivirus in the Retroviridae family, akin to HIV-1 in genome structure and antigenicity. EIA is an important infectious disease in equids, characterized by anemia, persistent infection, and repeated fevers. The EIAV attenuated vaccine in China is the only lentiviral vaccine used on a large scale. Elucidating the mechanism of waning and induction of protective immunity from this attenuated vaccine strain will provide a ...
Brinkmeyer-Langford C, Raudsepp T, Gustafson-Seabury A, Chowdhary BP.A total of 207 BAC clones containing 155 loci were isolated and arranged into a map of linearly ordered overlapping clones over the proximal part of horse chromosome 21 (ECA21), which corresponds to the proximal half of the short arm of human chromosome 19 (HSA19p) and part of HSA5. The clones form two contigs - each corresponding to the respective human chromosomes - that are estimated to be separated by a gap of approximately 200 kb. Of the 155 markers present in the two contigs, 141 (33 genes and 108 STS) were generated and mapped in this study. The BACs provide a 4-5x coverage of the regio...
Gehlen H, Haubold A, Rohn K, Stadler P.In the present study we examined, if in Icelandic horses an increase in heart and/ or breathing rate is physiological and breed dependend or a sign of a pulmonary or cardiac disease. Therefore we examined 37 Icelandic horses with the prereport of being healthy. During clinical lung examination four horses showed symptoms of a pulmonary disease like increased breathing rate and enforced breathing at rest. These horses were excluded from the study. The other 33 horses were clinically normal. 17 of these horses were unridden (untrained) and 16 horses were regularly worked (trained). After clinica...
van Niekerk FE, van Niekerk CH.The effect of total protein intake and protein quality on the serum concentrations of certain reproductive hormones during the anovulatory, transitional and ovulatory periods were studied in 36 Anglo-Arab mares. High-quality protein stimulated FSH and LH production during the late transitional period. Serum progestagen and melatonin concentrations were unaffected by the quality of protein nutrition during the anovulatory period. Mares receiving high-quality protein exhibited a 10-14-day cyclical pattern of FSH release approximately 4-6 weeks earlier than the mares fed the lower-quality protein...
Hart LT, Broussard EA.Immunodiffusion antigen from spleens of horses infected with equine infectious anemia virus was prepared by methods employing freeze-thaw cycles and thiocyanate treatment. Thiocyanate (0.5 M) permitted the recovery of the greatest amount of antigen. Furthermore, it was most effective for recovery of immunodiffusion antigen from spleens which yielded unsatisfactory concentrations of antigen by the conventional freeze-thaw or water-extraction methods. The reactivity of the antigen did not appear to be affected by this chemical treatment.
Matthews AG.The author reviews some aspects of vision and ophthalmic disease in the horse and considers how some recent developments in ocular immunobiology and molecular pathology in other species may give pointers toward an understanding of disease processes in the horse.
Kunkle GA, Greiner EC.An episode of dermatitis in 12 horses and many animal handlers in the Veterinary Medical Teaching Hospital of the University of Florida was attributed to the straw itch mite, Pyemotes tritici. The mite was found in abundance alfalfa hay that recently had been delivered to the hospital. Papules were the most common cutaneous lesions, and these developed on areas of the body to which the mites had easiest access. The clinical course was self-limiting, remitting when the hay supply was depleted.
Barton AK, Kershaw O, Gruber AD, Gehlen H.Recently, a syndrome called "equine idiopathic hemorrhagic cystitis" was described and clinical features compared with bladder neoplasia. In this case report, we describe a case of hemorrhagic cystitis with a favorable outcome in a high-performance dressage horse, in which exercise intensity might be the etiologic factor for the development of bladder-wall hyperplasia and hematuria. A 14-year-old Warmblood gelding was presented with a history of hematuria of 2-day duration. The high-level dressage horse had performed on the previous 3 weekends and was trained at least three times a week at per...
Ambrisko TD, Moens Y.In a previous in vitro study using saline medium, the authors showed that certain drugs changed the voltages of lithium dilution cardiac output (LiDCO) sensors and also influenced their accuracy in measuring lithium concentrations. These two parameters correlated and so we examined whether such drug-sensor interaction exists when LiDCO sensor was exposed to xylazine in blood. Methods: Five healthy adult warm-blood horses were injected with 0.5 mg kg(-1) xylazine i.v. Physiological saline solution and venous blood were consecutively sampled through the same LiDCO sensor at 60, 45, 30, 15, and 0...
Souza CRS, Farnsworth KD, Ragle CA.The objective of this study was to assess and compare the bursting pressure and mode of failure of a 2-strand continuous crossing suture pattern and a simple continuous suture pattern for closure of the equine linea alba. No difference in bursting strength or mode of failure was found between the 2 suture patterns. Comparaison de la force d’éclatement des incisions des sutures simples continues et des sutures croisées continues à deux fils pour la fermeture de la linea alba des équidés. Cette étude avait pour objectif d’évaluer et de comparer la pression d’éclatement et le mode d...
De Moor A, Van Den Hende C, Moens Y, Desmet P.A long-lasting increase of the plasma bromide concentration was found in 25 horses after clinical halothane anesthesia. The plasma bromide concentration was significantly (P less than 0.005) increased at the end of anesthesia. In 18 horses, peak values were reached between 48 and 72 hours after anesthesia. Eighteen days after horses had been anesthetized, the plasma bromide concentration remained significantly (P less than 0.005) increased. Significant correlation was not found between the total dose of halothane and the plasma bromide concentration. In 1 horse reanesthetized with halothane 4 ...
Knych HK, Stanley SD, Benson D, Arthur RM.Guaifenesin is an expectorant commonly used in performance horses to aid in the clearance of mucus from the airways. Guaifenesin is also a centrally acting skeletal muscle relaxant and as such is a prohibited drug with withdrawal necessary prior to competition. To the authors' knowledge, there are no reports in the literature describing single or multiple oral administrations of guaifenesin in the horse to determine a regulatory threshold and related withdrawal time. Therefore, the objective of the current study was to describe the pharmacokinetics of guaifenesin following oral administration ...
Annandale CH, Schulman ML, Kirkpatrick RD.Twelve pony mares were randomly assigned to either a control or a treatment group and inseminated with fresh, raw semen from a single stallion of known fertility in a cross-over trial design. Pregnancy was diagnosed by transrectal ultrasound 12-14 days post-ovulation and then terminated by administration of a luteolytic dose of cloprostenol. Treatment mares received a uterine instillation of 100 ml of electrochemically activated (ECA) saline 4-12 hours post-insemination. Control mares received no treatment post-insemination. Per cycle pregnancy rate was 58.3 % in the control group and 50 % in ...
van Bömmel-Wegmann S, Gehlen H, Barton AK, Büttner K, Zentek J, Paßlack N.Little is known about the animal- and diet-related factors that could interfere with the plasma zinc (Zn) concentrations of equines. Additionally, the adequacy of plasma to reflect changes in the Zn intake is unclear. In the first part of this study, the plasma Zn concentrations of hospitalized horses and ponies ( = 538) were measured and evaluated for the impact of the age, sex, horse type, and internal diseases of the animals. In the second part, the effects of increasing dietary Zn chloride hydroxide and Zn methionine supplementations were assessed on the plasma and mane hair Zn concentrati...
Sloet van Oldruitenborgh-Oosterbaan MM, van Duijkeren E.Salmonellosis is a worldwide problem of both men and animals. Equine salmonellosis is an increasing problem and a review of the recent knowledge is given. Etiology, symptomatology, diagnostic procedures, therapy and prevention are discussed.
Pemberton AD, John HA, Ricketts SW, Rossdale PD, Scott AM.Failure to inhibit proteinases can lead to excessive tissue damage. The possibility that the severity of endometritis in Thoroughbred mares correlates with the haplotypes of plasma alpha 1-proteinase inhibitor (alpha 1-PI) expressed was investigated in two groups of mares. In mares with pyometritis before treatment, the frequency of the N haplotype, which is already high in the Thoroughbred population, was significantly increased when compared with that in a large published population. In mares with acute endometritis which persisted after treatment followed by sexual rest, the absence of S an...
Hudson BJ, Chicken C, Blishen A, Todhunter KH, Begg AP, Chan L, Karagiannis T, Raymond B, Bogema D, Adkins AR, O'Sullivan CB, O'Rourke BA....We describe three cases of osteoarticular infection (OAI) in young thoroughbred horses in which the causative organism was identified by MALDI-TOF as . The pattern of OAI resembled that reported with infection in humans. Analysis by 16S rRNA PCR enabled construction of a phylogenetic tree that placed the isolates closer to and , rather than . Average nucleotide identity (ANI) comparison between the new isolate and and however revealed low probability that the new isolate belonged to either of these species. This preliminary analysis suggests the organism isolated is a previously unrecognis...
