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.
Brown MP, Gronwall RR, Martinez DS, Beal C.Six healthy pony foals, from 2 to 11 days of age, were given a single IM injection of amikacin sulfate (250 mg/ml) at a dosage rate of 7 mg/kg of body weight. Serum amikacin concentrations were measured serially over a 24-hour period. The mean peak serum concentration was 14.7 micrograms/ml at 0.5 hour. The elimination rate constant for amikacin was 0.24/hour, the elimination half-life was 3.0 hours, and the apparent volume of distribution was 0.58 L/kg.
Carroll JF, Schmidtmann ET.The American dog tick, Dermacentor variabilis (Say), was the only ixodid tick found feeding on horses in Montgomery County, Md., from May to August. Average tick burdens were low (less than one tick per horse per week), but >80% of 33 horses examined weekly were exposed to tick feeding during the summer. Of the 98 ticks collected, 78% were attached to the tail and 12% were present in the mane. Host-seeking adult D. variabilis were active on vegetation in pastures from May to early August, with most specimens along hedgerows, woods margins, and horse paths.
Trim CM, Hanson RR.The intravenous administration of xylazine (1.1 mg/kg bodyweight) in six ponies resulted in a significant increase in urine output over two hours, with maximum flow occurring between 30 and 60 minutes after injection. Urine specific gravity, osmolality and glucose concentration decreased. Renal clearance of endogenous creatinine was unchanged. Significant increases in the excretion of potassium and chloride occurred. Plasma glucose concentration was increased 30 minutes after the administration of xylazine by a mean value of 37 per cent. Serum osmolality and sodium, potassium and chloride conc...
Carter JD, Hird DW, Farver TB, Hjerpe CA.Salmonellosis was studied during an 11-year period (July 1971 through June 1982) in 245 hospitalized horses. Ten years' data (207 cases) were analyzed in a time series study. Peak seasonality of the disease was from June through September. The cycle curve revealed 3 major outbreaks, with no apparent periodicity. Eighteen Salmonella serotypes caused clinical salmonellosis in horses, but 84% of the cases and 90% of the deaths were caused by 5 serotypes: Salmonella typhimurium, S typhimurium var copenhagen, S anatum, S kottbus, and S saint-paul. Overall, the case fatality rate was 44.9%. Excludin...
Hird DW, Casebolt DB, Carter JD, Pappaioanou M, Hjerpe CA.A case-control study to identify risk factors associated with isolation of Salmonella was accomplished, using data from records of horses hospitalized in the period July 1971 through June 1982. Horses in which nasogastric tubes were passed were at 2.9 times greater risk of having Salmonella isolated, compared with horses that did not undergo this procedure. Horses treated with antibiotics parenterally were at 6.4 times greater risk, and those treated with antibiotics orally and parenterally were at 40.4 times greater risk of developing salmonellosis, compared with horses not receiving such tre...
Dyson S.The results of a detailed investigation of 58 horses with suspected shoulder lameness are described. Lameness was found to originate distal to the shoulder region in 22 horses. No diagnosis was reached in five horses. Genuine shoulder problems occurred in 29 horses. The clinical signs of shoulder lameness are described and contrasted with lower limb lameness. The limitations of currently available diagnostic techniques are discussed. Problems identified in the shoulder region included osteochondritis dissecans, subchondral bone cysts, arthrosis, fracture, luxation, septic arthritis and soft ti...
Black HE.Non-steroidal anti-inflammatory drugs represent the most heavily prescribed and used class of drugs in human medicine. Most are derivatives of either salicylates, propionic acid, indoleacetic acid, anthranilic acid, pyrazolone, or oxicams. They depress the synthesis of prostaglandins from arachidonic acid by reversible inhibition of the enzyme cyclooxygenase. In the kidney, prostaglandins PGE2 and PGI2 modulate the vasoconstrictor effects of angiotensin II, norepinephrine, and vasopressin. In the presence of volume contraction, anesthesia, or disease states associated with high levels of these...
Hawkins KL.Bilateral salpingitis, hydrosalpinx and oophoritis were diagnosed in a mare with concurrent lymphosarcoma. Salpingitis, hydrosalpinx and oophoritis are rare in the mare (1,2,3,5,8,9,11-13). Bilateral salpingitis is an important cause of infertility in all species and is most often due to ascending infection (3-5,10,11). The source of salpingitis in this mare probably was ascending infection from the uterus after parturition. The apparent infertility of the mare was attributed to debilitation from the lymphosarcoma and multiplicity of genital pathoses.
Wood JM, Mumford J, Schild GC, Webster RG, Nicholson KG.Single-radial-immunodiffusion (SRD) provides a sensitive and reproducible in vitro assay for haemagglutinin (HA) concentration in inactivated influenza vaccines. The use of SRD for human influenza vaccine standardization and application for equine and avian influenza vaccines is discussed. In clinical trials, vaccine HA concentration measured by SRD has been shown to be directly related to antibody responses and to protection against challenge. The use of SRD may considerably reduce the usage of animals for potency testing of veterinary influenza vaccines.
Magnuson N, Perryman L, Wyatt C, Mason P.Severe combined immunodeficiency (SCID) occurs in horses of the Arabian breed and is inherited as an autosomal recessive trait1. Affected foals are severely lymphopenic with an absence of functional B and T lymphocytes.2 The few lymphocytes that can be found in affected foals resemble large granular lymphocytes (LGL) and can be grown long-term with media containing interleukin-2 (IL-2).3 The disorder is restricted to the lymphoid system, as other leukocytes are functionally and quantitatively normal.4
Jaussaud P.Flunixin is a non-steroidal anti-inflammatory agent, with a potent analgesic activity and a slight toxicity. It is largely used in horses, in the form of meglumine salt, for the treatment of inflammatory diseases or colics, and often identified in dopage cases. Physical and chemical properties of the drug, its pharmacological and toxicological properties, and its use in equine species are depicted.
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.
Hollanders B, Mougin A, N'Diaye F, Hentz E, Aude X, Girard A.A new two-step gradient technique has been used in the separation of the different classes of lipoproteins from the serum of cows, horses, dogs, pigs, rabbits and rats. Total lipoproteins were first isolated at d 1.21 then floated through a d 1.006 to d 1.21 gradient. Collection by mean of a gradient fractionator provided directly comparable lipoprotein profiles, allowed the determination of the exact density range of each lipoprotein class and the fraction by fraction analysis of composition. Cholesterol and apo AI recoveries were high. Horse, dog, rabbit and pig exhibited three distinct lipo...
Gomez-Perretta C, Armas-Portela R, Stockert JC, Tato A, Ferrer JM.The acidophilic reaction of eosinophil leucocyte granules from human, pig and horse blood smears was investigated by using May-Grünwald-Giemsa staining after previous treatment with EDTA and sodium citrate solutions. The same peak at 530 nm, but absorption values considerably higher than those of controls, were found in eosinophil granules after application of chelating agents, indicating that removal of metal cations could unmask basic groups in these structures.
Gregory MW, Longstaff JA, Giles CJ.Ciliates resembling Polymorphella ampulla (Dogiel, 1929) were found in large numbers in the crypts and lamina propria of the caecum and colon of a one-year-old Thoroughbred gelding that had shown recurring bouts of chronic diarrhoea and weight loss over a 5-month period. A heavy burden of helminths, mainly cyathostomes (trichonemes) was present at post-mortem examination and no significant bacterial pathogens were recovered. It was considered that the Polymorphella (which is normally a commensal organism) had in this case assumed a secondary pathogenic role.
Kaminski M, de Andres Cara DF.Genetic variants at eight blood loci were analysed, disclosing in Andalusian breed six rare markers: variants J of transferrin, H of esterase, D and S of Xk, M and W of prealbumin. Two of these, TfJ and PrM appear as characteristic markers of Andalusian breed. Allelic frequencies showed minor differences between Spanish (300 horses) and Lusitanian (100 horses) populations. Comparison was established with historically related breeds, Thoroughbreds or Connemara, and with Arab horses because of a presumed relationship. No visible similarities in genetic profiles were found with two former breeds,...
Rando A, Di Gregorio P, Masina P.Horse DNA samples digested with PstI and probed with the rabbit beta 1 globin gene show three phenotypes determined by one fragment of variable length (about 5.1 or 3.3 kb). Family data demonstrate that these fragments segregate as Mendelian alleles. The frequencies of the two alleles are 0.66 for the 3.3-kb fragment and 0.34 for the 5.1-kb one. Another polymorphism has been detected with BamHI. Again three phenotypes determined by two alleles (fragments of 7.5 and 3.8 kb) have been observed. Allelic frequencies of the 7.5- and 3.8-kb fragments are 0.24 and 0.76 respectively. The two polymorph...
Schryver HF, Oftedal OT, Williams J, Cymbaluk NF, Antczak D, Hintz HF.Milk samples were obtained in early and/or late lactation from Przewalski horses, Hartmann's zebras, Grant's zebras, domestic horses, ponies and a mule mare made pregnant by embryo transfer. Samples were compared for their content of total solids, ash, calcium, phosphorus, magnesium, sodium, potassium, copper, zinc and iron. Milk from the Przewalski horses, Hartmann's zebra and the domestic horse had similar mineral composition and the content of minerals was higher in early than in late lactation. Milk from the domestic mule contained the lowest concentration of calcium, phosphorus and zinc b...
Wyn-Jones G, May SA.Over a period of seven years, 30 horses were treated by surgical arthrodesis for lameness resulting from osteoarthrosis of the proximal intertarsal, distal intertarsal and tarsometatarsal joints (bone and occult spavin). Twenty-five horses were affected in one hock only and five were affected bilaterally. Four different techniques for achieving arthrodesis were used. Fourteen out of 18 horses (78 per cent) with involvement of the distal intertarsal and tarsometatarsal joints only and six out of 11 horses (55 per cent) in which the proximal intertarsal joint was also involved became sound follo...
Kalinskiĭ MI, Kamenetskaia OV, Skorik LG, Tishchenko GN.The paper deals with possibility to regulate in a proper direction the acid-base state in race horse blood administering carbostimulin at rest and under physical exercises. The preparation is shown to favour an increase in alkaline blood reserves in race hours at rest and to prevent acidotic changes caused by physical exercises. The results obtained show a promising use of carbostimulin for the directed correction of the acid-base state of blood in race horses aimed at increasing the efficiency of the training process.
Bhardwaj A, Nayan V, Sharma P, Kumar S, Pal Y, Singh J.Equine pituitary gonadotropins (eLH, eFSH, eCG) are heterodimeric glycoprotein hormones with alpha (α) and beta (β) subunits. It is responsible for maintenance of pregnancy in mares during early gestation and fairly valuable for inducing superovulation in animals other than equines. The alpha subunit is common, while beta subunit is species-specific in all glycoprotein hormones. In the present investigation, molecular cloning and in silico characterization including homology modeling and molecular docking analysis of the equine chorionic gonadotropin (eCG) alpha subunit was carried out for g...
Bailey JV, Barber SM, Fretz PB, Jacobs KA.The records of 13 horses of various breeds with subluxation of the radiocarpal, intercarpal or carpometacarpal joint, or combinations of these were reviewed. Subluxation was most common at the carpometacarpal joint (n = 10) and concomitant fractures of individual carpal bones or metacarpus II and IV were seen (n = 12).Treatment comprised of immobilization in a full leg plaster cast for from four to 18 weeks. Three animals were euthanized, two because of cast complications and one because of a request by the owner. The remaining ten were saved to function as breeding animals.
Reddy VK, Kammula RG, Graham TC, Srungaram SK, Bowie WC, Hawthorne EW.Regional coronary blood flow was measured by injecting radioactive microspheres (15 mum +/- 5 in diameter) into the left atrium of anesthetized ponies with surgically prepared open thorax before and during occlusion of the coronary arteries. The normal blood flow to the myocardium of the interventricular septum and the left ventricular wall were highest, followed in decreasing order by the right ventricular wall, the interatrial septum, the atrial walls, and the valves. Measurement of transmural blood flow in the normal left ventricle yielded a mean endocardial/epicardial flow ratio of 1.36 in...
Pérez-Écija A, Estepa JC, Barranco I, Rodríguez-Gómez IM, Mendoza FJ, Gómez-Laguna J.Verrucous hemangiomas are a rare specific variant of equine skin tumors not well described in the literature. An 8-year-old gelding presented a unilateral lesion on the pastern. Macroscopically, the mass showed a warty and verrucous surface with focal ulcerations. The histology showed a dermal proliferation of endothelial-layered capillaries and venules separated by a delicate stroma of scant fibroblasts and collagen deposition, with pseudoepitheliomatous hyperplasia (exuberant reactive irregular epithelial hyperplasia with tongue-like projections extending into the dermis, mimicking downgrowt...
Firth EC, Poulos PW.Selective perfusion and microangiographic examination of the radius and metacarpus of 30 foals were performed. Vessels of extraosseous origin supplying the peripheral part of the metaphysis were not demonstrated in young foals, but became more obvious in older animals. The development of this vessel system coincided with the reduction of transphyseal vessels from the epiphysis crossing the growth plate.
Orsini JA, Roby KA.A modified surgical procedure for creation of a carotid loop for repeated percutaneous sampling of arterial blood gas was performed on 8 Holstein heifers and 14 horses. This approach permitted sampling of blood gas via fine-needle aspiration (one to three times daily) and/or catheterization for extended periods. It offers several advantages over previously reported techniques, including greater accessibility, absence of postoperative complications such as hematoma formation, and absence of foreign materials supporting the loop.
Althouse GC, Seager SW, Varner DD, Webb GW.An experiment was conducted to evaluate three commercially available test kits, the Azostix, Multistix and Uric-acid test, for the detection of urine in the equine ejaculate. Azostix, which tests for urea nitrogen, consistently detected urine in the equine ejaculate. Urine contamination was evident when a color change occurred in the reagent pad, going from yellow to green after 10 sec of exposure. The sensitivity of Azostix to urea nitrogen in contaminated samples was 39 mg/dl. The Multistix test kit also successfully detected urine in semen. In the Multistix nitrite pad the color changed fro...
Albrecht BA, MacLeod JN, Daels PF.At the onset of equine chorionic gonadotrophin (eCG) secretion, eCG stimulates luteal androgen and oestrogen production. Although eCG concentrations increase exponentially from day 37 to day 60 of gestation and eCG is detectable in maternal serum until about day 120-150 of gestation, luteal androgen and oestrogen production peaks between 5 and 10 days after initial exposure to eCG and then decreases gradually. It is not clear how eCG regulates luteal androgen and oestrogen production. In the present study, the steady-state mRNA expression of 3beta-hydroxysteroid dehydrogenase (3beta-HSD), cyto...
Blikslager AT, Tate LP, Weinstock D.Effects of neodymium:yttrium aluminum garnet (Nd:YAG) laser irradiation on equine endometrium were evaluated in vitro and in six mares with endometrial cysts. The Nd:YAG laser was applied to six endometrial sites, in each of five uterine specimens, with power densities of 5659 to 33,954 J/cm2. Depth of tissue ablation was measured and graded on histologic sections of the tissue lesions. Power density had a significant effect on the depth of tissue ablation (p < .001). Grade 3 lesions (full-thickness ablation of the endometrium) were created with energy densities of 16,977 to 33,954 J/cm2. Six ...
Andersson B, Augustinsson O, Bademo E, Junkergård J, Kvart C, Nyman G, Wiberg M.The primary aim of the study was to evaluate the potential value of intravenous (i.v.) infusion of angiotensin II (AII) for phonocardiographic differential diagnosis of equine valvular insufficiency. Ten-minute AII infusions at 4.5-33 pmol kg-1 min-1 induced clear-cut dose-dependent rises in systemic arterial blood pressure (aBP), whereas the pulmonary aBP remained largely unaffected. It implies that i.v. infusion of AII at about 10 pmol kg-1 min-1 could be a valuable tool for the acoustic differentiation between mitral and tricuspid valvular dysfunction in the horse. The infusion at, and abov...
Love CC, Blanchard TL, Varner DD, Brinsko SP, Voge J, Bliss S, Sudderth K, Teague S, LaCaze K.An experiment was conducted to determine whether cooled semen quality could be maintained for a longer interval by conducting daily centrifugation of extended semen, with resuspension of the sperm pellet in fresh extender. Semen treatments included SP10NC and SP50NC which contained 10 and 50% seminal plasma, respectively, were not centrifuged (NC), and were stored at 4 to 7 °C for 96 h. Treatments SP10C and SP50C contained 10 and 50% seminal plasma, respectively, but were centrifuged (C) after 24, 48, and 72 h of cooled storage, with daily resuspension in fresh extender containing 10% seminal...
Yoxall AT.The principles of radiological protection are summarised and consideration is then given to problems, which may confront the equine practitioner, in the fulfillment of these principles during diagnostic radiography of the limbs, head, and spine of the horse. The place of anaesthesia in such procedures is discussed and the special problems associated with therapeutic radiography of the horse are considered.
Denyer MS, Crowther JR.Antigenic differences within equine-1 and equine-2 isolates of influenza were studied by haemagglutination inhibition tests, indirect ELISA and competition ELISA, using the same antisera. Better differentiation was obtained with the competition ELISA than with the other two tests. All three methods produced similar relationships within the equine-1 isolates but differed in their ability to differentiate the equine-2 isolates where the competition ELISA was superior and produced epidemiologically sensible results. In all three tests, post-infection ferret and horse sera were more useful in disc...
Van Hoogmoed L, Rakestraw PC, Snyder JR, Harmon FA.To determine the in vitro effect of various prostaglandins (PG) and nonsteroidal anti-inflammatory drugs (NSAID) on contractile activity of the large-colon taenia of horses. Methods: 14 healthy horses. Methods: The taenia was collected from the ventral colon, cut into strips (2 X 10 mm), and mounted in a tissue bath system (20-ml capacity) that contained oxygenated Krebs buffer solution warmed to 37.5+/-0.5 C. After equilibration, incremental doses of PGE2, PGF2alpha, PGl2, flunixin meglumine, carprofen, ketoprofen, and phenylbutazone were added to the baths, and contractile activity was recor...