Veterinary medicine for horses encompasses the study and application of medical practices to diagnose, treat, and prevent diseases in equine species. This field involves a comprehensive understanding of equine anatomy, physiology, pathology, and pharmacology. Veterinary practitioners employ a range of diagnostic tools and therapeutic interventions to address health issues in horses, including lameness, gastrointestinal disorders, respiratory conditions, and infectious diseases. Preventative care, such as vaccination and deworming programs, is also a significant aspect of equine veterinary medicine. This page gathers peer-reviewed research studies and scholarly articles that explore various aspects of veterinary medicine as it pertains to horses, including advancements in diagnostic techniques, treatment protocols, and preventive health strategies.
Ribbeck R, Ilchmann G, Hiepe T.Research into the immunological diagnosis of gasterophilosis. So far there have been no reliable methods of diagnosing equine gasterophilosis intra vitam. Horses from the G.D.R. and the M.P.R. spontaneously infected with Gasterophilus spp. were tested for antibodies by the immunotechniques of counterimmunoelectrophoresis after Pesendorfer, passive haemagglutination and the intradermal test using antigen made from larvae of all 6 Gasterophilus spp. present in the palaearctis. All 3 techniques produced positive results. The intradermal injection produced an immediate reaction. A correlation betw...
Gunson DE, Halliwell RE, Minor RR.A 2-year-old female horse had large areas of hyperextensible, fragile skin that were interspersed with areas of normal skin. Affected skin tore easily and contained reduced amounts of dermal collagen. Collagen fibers were fragmented and disorganized, and in trichrome-stained sections, many fibers had abnormal red-stained centers. Electron microscopy showed that many collagen fibers had discrete foci of degradation in which the fibrils were fragmented, loosely packed, and widely separated by granular material. Collagen fibril fragments were present in secondary lysosomes in dermal fibroblasts, ...
Seanor JW, Byars TD, Boutcher JK.Renal dysfunction secondary to GI disorders may be relatively common in horses. Persistent dehydration of 8-10% of body weight can lead to prerenal azotemia, which may result in renal ischemia and renal disease if uncorrected. Dehydrated azotemic horses with a urine specific gravity less than 1.018 may have renal disease. Urine specific gravity readings greater than 1.025 usually indicate normal kidney function. A urine Na level less than 20 mEq/L and a urine/plasma creatinine ratio greater than or equal to 20:1 indicate prerenal problems. Use of nephrotoxic drugs should be avoided in septicem...
Szwarocka-Priebe T, Gill J.Twenty Thoroughbred 3 year old horses (10 stallions and 10 mares), trained and raced at the Warsaw Race-Course were studied from March through November. Blood was taken approximately every 8 weeks to determine the activities of aspartate and alanine transaminases, acid and alkaline phosphatases and aldolase. It was observed that the activities of aspartate aminotransferase and alkaline phosphatase reached their maxima in July and alanine transaminase in May. The activities of acid phosphatase and aldolase showed their minima in July. Comparing these data with the literature it was noted that t...
Miller PJ, Holmes JR.A method is described of processing transaortic valve pressures in the horse using the first derivative of the left ventricular pressure to define the beginning and end of each systolic complex. To determine the beginning of each systole three definitions of left ventricular end diastolic pressure (LVEDP), based on a 100, 150 or 200 mmHg/sec rate of left ventricular diastolic pressure rise, were evaluated. These definitions were also evaluated for their ability to determine isovolumic contraction time (ICT) and pulse interval. The best of these, LVEDP 150, was defined as the last point in dias...
Hintz HF.Consistency of exercise and diet are important in colic prevention. Water should be offered before and after feeding. Fast-growing foals suckling heavily lactating mares may overeat grain at weaning. Creep feeding to accustom the foal to eating grain and gradually increasing the grain intake after weaning are helpful in preventing colic in foals. Stallions may overeat grain when taken off pasture in hot weather. Feeding hay initially and grain later helps avoid colic in these stallions. Type-D Clostridium perfringens may cause enterotoxemia in foals. Corn should be fed in moderation. High-Mg d...
Lyons ET, Drudge JH, Tolliver SC, Swerczek TW, Crowe MW.A total of 396 Thoroughbreds (86 males, 293 females, and 17 geldings) in Kentucky, 1 to 30 years of age, were examined at necropsy for presence of Anoplocephala perfoliata (2 female horses were not examined) in the cecum for lesions of Draschia megastoma in the stomach, during the 1-year period of Mar 1, 1982 through Feb 28, 1983. Prevalence of A perfoliata was 53% and of lesions of D megastoma was 63%. All lesions of D megastoma were partially or entirely in the glandular region of the stomach. Distances of the midpoint of these lesions from the margo plicatus varied from 0 to 290 mm. The cen...
Ostblom LC, Lund C, Melsen F.Although the diagnostic criteria of navicular disease are generally accepted in practice, their limitations are recognised. However, the authors believe that navicular disease per se is reversible and that only secondary changes like adhesions to the deep flexor tendon or spur formations are irreversible. This hypothesis is supported by the results presented of the effect of the application of an egg-bar shoe, which caused permanent cessation of signs of navicular disease in more than 50 per cent of treated cases. The egg-bar shoeing technique can be usefully applied in practice.
Ketelaars HC, Peters JG, Anzion RB, Van Ginneken CA.The isolation, partial identification and quantitative determination of four guaiphenesin glucuronides in plasma and urine of the horse is described. The identity of the glucuronides was checked by UV and fluorescence spectrophotometry, by NMR spectrometry and by mass spectrometry after permethylation. The applicability of the procedure to pharmacokinetic studies is demonstrated.
Green EM, Cooper RC.A technique for continuous caudal epidural anesthesia in the horse was developed in trials involving 8 healthy adult horses. The injection site was the first intercaudal (intercoccygeal) space. A Huber point directional needle (Tuohy or Hustead) with a stylet was preplaced into the epidural space, used as a guide for an epidural catheter, and then removed, leaving the catheter in situ in the epidural space. A 2% solution of lidocaine hydrochloride was used as the anesthetic agent at an initial dose of 8 ml for an adult animal (474 kg to 560 kg). Repeated 4-ml doses were administered immediatel...
Muir WW, McGuirk SM.Hemodynamic measurements were obtained from 17 horses with atrial fibrillation or flutter. Eight horses had atrial fibrillation of unknown duration. In 7 horses, atrial fibrillation developed during anesthesia. Atrial flutter developed during recovery from anesthesia in 2 horses. Hemodynamic measurements were considered normal in 7 of 8 conscious horses with atrial fibrillation. Cardiac output was decreased and pulmonary arterial blood pressure and right atrial pressure were increased in 1 conscious horse which had signs of congestive heart failure. Arterial blood pressure decreased in 5 of 7 ...
Campbell ML, Colahan PC, Brown MP, Grandstedt ME, Peyton LC.During a 3-year period, cecal impaction was diagnosed in 21 horses (mean age, 8 years) at exploratory celiotomy or necropsy. In 7 horses, typhlotomy was used to remove the impaction; 2 horses treated by fluid injection of the impaction did not survive. The 12 other horses had cecal rupture. Surgical correction was not possible in those horses because of inaccessibility of the rupture site. Postmortem examination of the rupture sites did not reveal a cause other than cecal impaction. The duration of clinical signs before rupture ranged from 4 to 96 hours.
Burrows R, Goodridge D, Denyer MS.Vaccinated yearlings , two-year-old and in-foal pony mares with appropriate controls were exposed to aerosols of a subtype 1 virus one to two months after two or three vaccinations; all became infected. No obvious differences in the febrile responses, clinical signs and subsequent abortions were found between vaccinated and control mares. All vaccinated yearlings and two-year-old ponies developed a febrile respiratory disease but this was less severe than that suffered by the controls and the amounts and duration of virus shedding were reduced.
Mumford JA, Bates J.Serological responses following two and three doses of an inactivated equid herpesvirus 1 ( EHV -1) vaccine containing a subtype 1 strain were examined in yearling ponies. Complement fixing antibody responses were significantly higher against the subtype 1 vaccine strain than against a subtype 2 virus. Complement fixing antibody responses declined rapidly after the second dose of vaccine and had returned to almost pre-vaccination levels eight weeks after the second dose of vaccine. Complement fixing antibody titres to the heterologous subtype 2 strain increased after each successive dose of va...
Yamagishi H, Ide S, Eiki T, Eiguchi Y, Nagamine T, Igarashi Y, Yoshioka I, Matumoto M.ESK cells, a stable cell line derived from a swine embryo kidney, were found to be a good medium for plaque formation of the Prague and Miami strains of equine influenza virus. Factors influencing the plaque formation were investigated and a plaque assay for these viruses was worked out. The method is not only simple enough for routine use, but also is as sensitive as the egg inoculation method. The method was readily adapted for a neutralization test.
Nyack B, Padmore CL, Dunn D, Kufuor-Mensan E, Mobini S.A 10-year-old Tennessee Walker gelding, with a history of progressive weight loss, intermittent colic and lethargy, had a slight fever, tachycardia, tachypnea, pallor, ascites and marked ventral edema. Blood analyses revealed anemia, leukocytosis, neutrophilia with a left shift, lymphopenia, monocytosis, hypoproteinemia and a slightly increased SDH level. Abdominocentesis produced red-orange fluid with many RBC and an increased fibrinogen content. Rectal palpation revealed a large mass in the left caudal abdominal quadrant. The animal died shortly after resection of the mass. The histopatholog...
Lamar CH, Masty J, Adams SB, Tacker WA.Myoelectrical and myomechanical activities of the distal portion of the jejunum and pelvic flexure were studied in 7 ponies, using permanently implanted monopolar and bipolar stainless steel electrodes. Dental acrylic embedded recording electrodes were surgically sutured to the serosal surface of the distal portion of the jejunum and pelvic flexure. Myoelectrically, regular spike bursts and irregular spike bursts were observed in the jejunum. Short spike bursts and long spike bursts were recorded and associated with spike potentials, using impedance recording techniques. Electrical and mechani...
Lindberg R.A morphological study on equine granulomatous enteritis (EGE) in 13 horses is presented. All horses were young (1 to 5 years old) standardbreds. Based on gross pathology, cases were classified into those with diffuse (11 cases) and those with localized (2 cases) small bowel lesions. The granulomatous reaction in the gut was marked by diffuse and patchy infiltrates and distinct granulomas, composed of epithelioid cells, macrophages and lymphoid cells, and was devoid of necrosis. Salient accompanying features of the small bowel included lymphoid hyperplasia, peri-lymphatic and transmural inflamm...
Dubin A, Potempa J, Silberring J.alpha 2-macroglobulin was isolated by polyethylene glycol precipitation, gel filtration on Sephacryl S-300 and DE-52 cellulose chromatography, with 20% yield. The preparation obtained was homogenous as tested by biochemical and immunological criteria. Its molecular mass was estimated at 800,000, comprising of four identical subunits. The isoelectric point of our preparation was 4.8 and two molecules of serine proteinases per 1 molecule of inhibitor were bound.
Engelking LR, Dodman NH, Hartman G, Valdez H, Spivak W.Effects of halothane anesthesia were investigated in ponies prepared surgically with chronic external biliary fistulas (T tubes) to determine the effects on liver function and biliary excretion during 2 hours of anesthesia. Four studies were performed on 2 ponies, 2 to 6 months after surgery with the enterohepatic circulation held intact between studies. Intravenous bile acid infusion was used to maintain steady-state bile flow, bilirubin, and bile acid excretion during each study. Compared with the immediate 2-hour preanesthesia values (base line), halothane caused a 138% increase in bilirubi...
Bossut DF, Page EH, Stromberg MW.Cutaneous pain thresholds to pinprick, pinch, and heat stimuli were quantified during control and electroacupuncture trials in 23 horses. Pain thresholds for 8 areas of the body during control trials (no needles) were statistically compared with pain thresholds measured in the same areas of the same horse when given electroacupuncture treatment. Statistically significant increases of pain threshold were interpreted as induced analgesia and occurred mainly in 5 areas of the trunk, but not in the head or extremities. Analgesic efficacy varied between sexes and among 3 groups of points chosen fro...
Alexander S, Irvine CH.Mares were bled once daily throughout a cycle, or 3 times daily from the first day of oestrus to the 2nd day after ovulation. LH was measured by heterologous radioimmunoassay and by an in-vitro bioassay based on LH-stimulated testosterone production by mouse Leydig cells. The patterns of bio- and immuno-active LH during the oestrous cycle were similar but not identical, so that in both groups of mares the ratio of biological: immunological (B:I) activity during the LH surge was significantly higher before than after ovulation (P less than 0 . 001). Considerable individual variation in cycle me...
Wood T, Tai CL, Taylor DG, Woods WE, Wang CJ, Houtz PK, Tai HH, Weckman TJ, Yang JM, Sturma L.Detomidine is a potent non-narcotic sedative agent which is currently in the process of being approved for veterinary clinical use in the United States. Since no effective screening method in horses is available for detomidine, we have developed an 125I radioimmunoassay for detomidine in equine blood and urine as part of a panel of tests for illegal drugs in performance horses. Our 125I radioimmunoassay has an I-50 for detomidine of approximately 2 ng/ml. Our assay shows limited cross-reactivity with the pharmacodynamically similar xylazine, but does not cross-react with acepromazine, epinephr...
Sasaki N, Tsuzuki N, Yamada M, Minami T, Yamada H.This study aimed to establish a standard dose and sample collection time for (13)C phenylalanine and (13)C-Dipeptide breath test in horses. To evaluate dose-dependent effects, healthy horses received 2.5 mg/kg, 5 mg/kg, and 10 mg/kg (13)C phenylalanine dissolved in 1 ml/kg distilled water and 1.25 mg/kg, 2.5 mg/kg, and 5 mg/kg (13)C dipeptide dissolved in 2 ml/ kg distilled water. Tmax was observed during the sample collection time. For (13)C phenylalanine, the standard deviation of Cmax at 5 mg/kg was lower than that of 10 mg/kg. For (13)C dipeptide, the standard deviation of Tmax was the low...
Kikuchi K, Kozai K, Hojo T, Sakatani M, Okuda K, Bai H, Kawahara M, Takahashi M.We investigated the electrical impedance of the reproductive tracts (vagina and uterine endometrial tissues) and the expression of mucus-related genes to identify the stage of the estrous cycle in mares. We first examined vaginal impedance in native Hokkaido mares during their estrous cycle and found no significant differences. However, impedance levels tended to decrease towards ovulation. Furthermore, we investigated the estrous cycle by measuring the electrical impedance of the uterine endometrial tissues obtained from carcasses of mares. We found that impedance levels in the endometrial ti...
Davies ME, Bingham RW.Two morphological types of spirochaete were found in the horse caecum measuring 4 to 6 micron by 0.3 to 0.4 micron and 6 to 8 micron by 0.1 to 0.2 micron. Attempts were made to culture the organisms but none survived subculture beyond the primary isolate. Electron microscopy revealed that many of the organisms were infected by bacteriophages.
Brom-de-Luna JG, Salgado RM, Felix MR, Canesin HS, Stefanovski D, Diaw M, Hinrichs K.In vitro production of horse embryos via intracytoplasmic sperm injection (ICSI) is a useful clinical and research technique. Current rates of blastocyst production are typically sub-optimal, and few methods to increase the rate of equine blastocyst development have been reported. Factors that might improve blastocyst production in a horse embryo culture system were explored. Myo-inositol is found in the horse oviduct and improves blastocyst development in other species, thus Experiment 1 was conducted to assess the effect of 10 mM myo-inositol added to Day 0-5 embryo culture medium, using hor...
Dintenfass L, Fu-lung L.Nineteen racehorses have been studied for haemorheologic factors as earlier studies showed a definite correlation between physical fitness and these factors in humans. Results included individual values for all viscosity factors, and the arithmetic means, the latter showing 4.70 +/- 0.49 cP for blood viscosity measured at a shear rate of 180 s-1; 1.100 +/- 0.048 cP for plasma viscosity; 1.045 +/- 0.063 for the rigidity of red cells defined by term 'Tk'; 42.2 +/- 4.1% haematocrit; 290 +/- 39 mg per 100 ml for fibrinogen level; and 278 +/- 75 mm h-1 for aggregation of red cells at 37 degrees C (...
Paine SW, Aldurdunji M, Garth-Greeves A, Muir T, Hincks PR.Hydroxyzine and cetirizine are first- and second-generation oral antihistamine drugs, respectively, used to treat allergic reactions in horses. Cetirizine is also a metabolite of hydroxyzine, which may lead to complexities in regulating their use in equine sporting events. The aim of the research was to be able to provide detection times (DT) from pharmacokinetic studies in thoroughbred horses to better inform trainers, and their veterinary surgeons, prescribing these substances for treatment of Thoroughbred racehorses. Six and two horses were given 9 repeated administrations of hydroxyzine HC...
El-Maaty AM, Gabr FI.Sixteen Arab lactating mares belonging to Al-Zahraa Arab Horse Stud underwent two ultrasound examinations at 3 weeks interval starting from the day of demonstration of foaling heat. In addition, daily blood samples were collected from parturition until after exhibiting first postpartum estrus (day 11) with daily observation of estrous signs. Both leptin and estradiol hormones were assayed. Mean day of foaling heat was 8.9+/-0.9 day. Most mares came in foaling heat during days 9 and 10 had high conception rate compared to those who came in estrus earlier or later. Estradiol levels were high aft...
Geerken C, Doreau M, Boulot S.Urea, compared with deuterium oxide (D2O) as a reference, was used as a body marker to estimate body water volume in ten 2-month old nursing foals. Plasma urea clearance was regular over 10 h and the R2 of the disappearance curve was between 0.93 and 0.98. Mean urea space was about 4% lower than D2O space, but the standard deviation of the proportion of water in body weight was higher with urea (3.8%) than with D2O (1.6%). Calculated urea entry rate was 49 mg/h/kg LW0.75.
Dewes HF, Lowe MD.Events leading to the deaths of two fillies at pasture are described. Pasture hay containing the flowering stages of Senecio jacobea (ragwort) had been fed three to four months earlier. Paddocks were subdivided with posts and rails treated with copper chrome arsenate. Six horses on the property chewed rails spasmodically. Both fillies presented with haemoglobinurea. Values in liver of 83 mg Cu kg and kidney 35 mg Cu kg wet weight and serum 1.4 mg Cu/l together with histophathology of seneciosis support a sequence of ragwort poisoning followed by copper accumulation in liver and kidney terminat...
Abd El Kader NA, Farghali HA, Abu-Seida AM, Salem NY, Khattab MS.Early detection of cystitis in equine is essential to improve the prognosis and outcome of therapy. However, the conventional white light endoscopy is not sufficiently accurate for this purpose. Hence, this study evaluated chromoendoscopy as a recent diagnostic tool for cystitis in female donkeys. For this purpose, 5 apparently normal donkeys (control group) and 5 female donkeys with cystitis (diseased group) were used. Physical and rectal examinations, urine analysis, white light cystoscopy, methylene blue-based chromoendoscopy and histopathology were performed in all animals. Turbid urine ex...
Johns I, McParland T, Mair T.Pleural effusion (PE) is reported to occur most commonly secondary to bacterial pneumonia or lung abscesses, with neoplastic effusions contributing the minority of cases. The majority of these reports originate from America and Australia, where long distance transport of horses, a recognised risk factor, appears to occur more frequently. Anecdotally, neoplastic PE is more commonly diagnosed in the UK. Objective: To describe the causes of PE in horses resident in the UK, and to identify potential markers that can help differentiate between infectious and neoplastic causes of PE. Methods: Retros...
Derossi R, Medeiros U, de Almeida RG, Righetto FR, Frazílio FO.The aim of the study was to evaluate and compare the effects of caudal epidural administration of meperidine (MP), lidocaine (LD), and a combination of the two (MPLD) in six mature saddle horses. Horses were randomly assigned to receive three treatments (MP 0.3 mg/kg; LD 0.2 mg/kg; and MPLD: MP 0.3 mg/kg and LD 0.2 mg/kg), with at least 1 week between treatments. Drugs were injected into the epidural space between the first and second coccygeal areas in conscious standing horses. Analgesia, ataxia, sedation, cardiovascular and respiratory effects, and rectal temperature were recorded at differ...
Bey O, Loeffler K, Sasse HH.In the course of ten horse-shows 248 horses were submitted to a short veterinary examination in the course of the horse controls that were introduced in 1991. In 143 horses (57.6%) animal cruelty preventive deficiencies were found. The results of the horse controls are compared to previous results and discussed from the point of view of animal protection.
Lyons ET, Swerczek TW, Tolliver SC, Drudge JH.At 4 days of age, an orphan horse foal born on a pasture was placed in a parasite-free stall. It was euthanized at 205 days of age and examination revealed numerous. Parascaris equorum specimens, ranging from 3.0 mm to adult size, indicating reinfections in the stall over an extended period of time. Initial infection of the foal was from stages on pasture. The foal had been observed repeatedly eating its own feces and the question is posed as to whether "recycling' of P. equorum eggs several times by coprophagy allowed time for embryonation and reinfection to occur.