Equine diseases encompass a wide range of health conditions that can affect horses, including infectious diseases, metabolic disorders, and genetic conditions. These diseases can impact the overall health, performance, and well-being of horses. Common equine diseases include equine influenza, equine herpesvirus, laminitis, and equine metabolic syndrome. Diagnosis and management of these diseases often require a combination of clinical evaluation, laboratory testing, and appropriate treatment strategies. This page gathers peer-reviewed research studies and scholarly articles that explore the etiology, pathophysiology, diagnosis, and treatment options for various equine diseases, providing valuable insights for veterinarians and researchers in the field.
Turner RM, Love CC, McDonnell SM, Sweeney RW, Twitchell ED, Habecker PL, Reilly LK, Pozor MA, Kenney RM.An 8-year-old stallion was evaluated because of recurrent urinary tract infections and chronic intermittent urospermia. After extensive diagnostic testing, it was hypothesized that the stallion had a reflex dyssynergia of the bladder and urethral sphincter. Initial attempts to manage the urospermia included semen fractionation, semen collection after voluntary urination, and use of semen extenders. None of these efforts reliably yielded a quality ejaculate. Administration of imipramine hydrochloride (1.2 mg/kg of body weight, PO, 4 hours prior to semen collection) was initiated in an attempt t...
Fischer AT, Vachon AM, Klein SR.Two mature stallions that were used for breeding purposes were admitted for evaluation of inguinal hernias. In 1 horse, the hernia was reduced per rectum by gentle traction applied to the intestine. In the other horse, the hernia was reduced by placing the horse in dorsal recumbency and applying external pressure over the scrotum. Both horses were observed for recurrence of the hernia. Seven days later, an elective laparoscopic technique for inguinal herniorrhaphy was performed on each horse, using polypropylene mesh. Complications did not develop, and both horses have successfully completed 2...
Wiler R, Leber R, Moore BB, VanDyk LF, Perryman LE, Meek K.V(D)J rearrangement is the molecular mechanism by which an almost infinite array of specific immune receptors are generated. Defects in this process result in profound immunodeficiency as is the case in the C.B-17 SCID mouse or in RAG-1 (recombination-activating gene 1) or RAG-2 deficient mice. It has recently become clear that the V(D)J recombinase most likely consists of both lymphoid-specific factors and ubiquitously expressed components of the DNA double-strand break repair pathway. The deficit in SCID mice is in a factor that is required for both of these pathways. In this report, we show...
Doxey DL, Milne EM, Harter A.The outcome for 35 horses with chronic dysautonomia which were kept in the hospital at the Royal (Dick) School of Veterinary Studies and subsequently returned to their owners is recorded. They constituted 42.7 per cent of the 82 chronic cases seen between 1991 and 1994; the other 47 horses were euthanased while in hospital. Of the 35 animals returned to their owners four died and 27 were available for follow up; of these 27, 12 were working competitively and six were being trained for future competitive work. It takes at least a year before it is clear whether a horse can compete successfully ...
van der Kolk JH, Grinwis GC.A three-year-old pregnant Dutch Warmblood mare was referred to the Department of Large Animal Medicine and Nutrition, Faculty of Veterinary Medicine, because of weight loss for 1 month. The main clinical features were (beside weight loss) moderate ventral oedema, enlarged mesenteric lymph nodes, and uniform thickening of the wall of the jejunum. Haematological evaluation revealed leukocytosis (15.9 G.l-1 with 18% lymphocytes and 1% eosinophils) and a decreased total serum protein and albumin concentration (35 g.l-1 and 36.3% albumin). At necropsy transmural eosinophilic enteritis was found in ...
Crabill MR, Watkins JP, Schneider RK, Auer JA.To determine the technique used, and the outcome for, double-plate fixation of comminuted fractures of the second phalanx of horses. Methods: Retrospective analysis of medical records. Methods: 10 horses with comminuted fractures of the second phalanx that were treated by use of double-plate fixation. Methods: Two 4- to 6-hole dynamic compression plates were abaxially placed to achieve arthrodesis of the proximal interphalangeal joint and fixation of the fracture of the second phalanx. Results: Arthrodesis and fracture healing were detected in all horses. Conclusions: Horses with comminuted fr...
Granstrom DE.This article reviews recent advances in laboratory diagnosis of equine parasitic diseases. Laboratory diagnosis of most equine parasitic diseases continues to rely on standard methods. Only laboratory diagnostic tests for EPM, cryptosporidiosis, and giardiasis were included. The criteria for testing and interpretation of results for each new diagnostic method were explained. Western blot and PCR testing for EPM and immunofluorescent staining with monoclonal antibodies for cryptosporidiosis and giardiasis were reviewed.
Fowden AL, Silver M.With the use of [U-14C]glucose tracer methodology, the rates of umbilical uptake, utilization, oxidation, and production of glucose were determined in nine chronically catheterized fetal foals in the fed state between 268 and 325 days of gestation (term approximately 335 days). At the same time, the rates of umbilical O2 and lactate uptake were measured in all nine fetuses by Fick principle. The mean fetal rates of umbilical glucose uptake, glucose utilization, and CO2 production from glucose carbon were 36.9 +/- 2.5, 36.4 +/- 1.7, and 117.7 +/- 17.4 mumol.min-1.kg fetal body wt-1, respectivel...
Battelli G, Galuppi R, Pietrobelli M, Tampieri MP.Fecal examinations of horses (Equus caballus) from studs in the province of Udine (Friuli Venezia Giulia region, east-northern Italy), carried out during two periods of the year 1993, revealed coccidian oocysts in six foals, two stallions and one mare. The species was identified as Eimeria leuckarti. This species was reported only once in Italy, more than 20 years ago (1972). For this reason, the prevalence of the parasite and the description of immature and sporulated oocysts are given.
Madigan JE, Rikihisa Y, Palmer JE, DeRock E, Mott J.The original objective was to determine seroprevalence of Ehrlichia risticii antibody among horses in California. On the basis of the unexpected results of the survey, an investigation into the accuracy and reproducibility of results of the indirect fluorescent antibody (IFA) test for E risticii was carried out. Methods: Prospective, seroprevalence study. Methods: Healthy horses (n = 655) and horses with clinical signs of equine monocytic ehrlichiosis (EME; n = 514) from various regions of California. Methods: The IFA test was performed. Results were compared with results of an ELISA and with ...
Barlough JE, Madigan JE, DeRock E, Dumler JS, Bakken JS.A Thoroughbred filly that developed clinical signs of equine granulocytic ehrlichiosis following inoculation with the human granulocytotropic ehrlichia was shown to be resistant to challenge with Ehrlichia equi, a closely related agent. This result further substantiates the close and potentially conspecific relationship between these two granulocytotropic ehrlichiae.
Mills PC, Dunnett M, Smith NC.The pharmacokinetics of oral and intravenous allopurinol was studied in five horses and compared with intravenous oxypurinol. The plasma concentration vs. time curves, following intravenous administration of 5 mg/kg, were best described by the biexponential equations Cp = 106.58e(-25.14t) + 159.93e(-10.96t) for allopurinol and Cp = 321.09e(-9.72t) + 82.39e(-0.44t) for oxypurinol, with an elimination half-life (t1/2 beta) of 0.09 h and an area under the curve (AUC) of 19.8 mumol.h/L after intravenous administration, while the t1/2 beta and AUC of oxypurinol were 1.09 h and 231 mumol.h/L, respec...
Mettenleiter EM.Diagnosis of diseases of the inner eye of horses is problematic, especially in cases where ophthalmoscopic examination is impaired or prevented by cloudiness of the optical apparatus. In addition, examination of retrobulbar affection normally only allows indirect conclusions on localization and extent of alteration. By the use of ultrasound on diseased horse eyes a detailed examination of the inner eye with retrobulbar structures is possible even in these cases. Here, we present several clinical pictures which are difficult or impossible to diagnose by ophthalmoscopical means. For example, son...
Dame JB, MacKay RJ, Yowell CA, Cutler TJ, Marsh A, Greiner EC.Equine protozoal myeloencephalitis (EPM) is a neurologic disease of horses caused by Sarcocystis neurona. The horse is a dead-end host for S. neurona and the definitive and intermediate hosts have not previously been identified. We hypothesized that S. neurona is actually Sarcocystis falcatula, a parasite that cycles in nature between Virginia opossums (Didelphis virginiana) and any of a variety of avian intermediate hosts. We extracted DNA from S. falcatula sarcocysts in the muscle of a brown-headed cowbird (Molothrus ater) and from schizonts in a fixed specimen of lung from a Moluccan cockat...
Larsen M, Nansen P, Henriksen SA, Wolstrup J, Grønvold J, Zorn A, Wedø E.This study was undertaken to examine the potential of the nematode-trapping microfungus Duddingtonia flagrans to survive passage through the gastrointestinal tract of horses and subsequently to destroy free-living stages of cyathostomes in faecal cultures. Three different oral dose levels were tested, two horses being used for each level. Faeces were collected twice daily and the numbers of parasite eggs per gram of faeces were determined. The numbers of infective third stage larvae which developed in faecal cultures were determined after the cultures had been incubated for 2 weeks at 24 degre...
Sticker LS, Thompson DL, Bunting LD, Fernandez JM, DePew CL, Nadal MR.Twelve light horse mares were fed a control diet that provided 100% of their maintenance protein and energy requirements for 7 d and were then either continued on the control diet or totally deprived of feed (with access to water) for 3 d . Plasma samples were drawn twice daily throughout the experiment, at 15-min intervals for 9 h beginning 45 h after feed removal, and at 10-min intervals around an exercise bout beginning 73 h after feed removal. Feed deprivation increased (P < or = .06) whole blood beta-hydroxybutyrate and plasma NEFA, urea N, L-lactate, and glucagon concentrations, decrease...
Thomas PG, Ignotz GG, Ball BA, Brinsko SP, Currie WB.Adhesion of equine spermatozoa to homologous oviduct epithelial cells (OEC) in vitro results in specific changes in spermatozoa and OEC function. To test the hypothesis that adhesion of spermatozoa affects protein synthesis and secretion by OEC, the following treatment groups were established in culture: OEC with culture medium only; control spermatozoa in culture medium only; OEC in coculture with spermatozoa; and OEC and spermatozoa in coculture, but physically separated by a microporous membrane. The experiment was replicated within each of 4 ejaculates from 3 stallions. De novo protein sec...
Paweska JT, Volkmann DH, Barnard BJ, Chirnside ED.Two in a group of five naturally seropositive donkey stallions were found to shed equine arteritis virus (EAV) in their semen as demonstrated by virus isolation. Direct intramuscular inoculation of sonicated semen from one virus-shedding stallion (S3) caused clinical disease in two donkeys from which virus was recovered and in which seroconversion was detected. Sexual transmission was confirmed in two mares mated to S3 when after a febrile response during which EAV was isolated from huffy coats and nasal and ocular exudates, both mares were found to have seroconverted. In-contact transmission ...
Bell K, Arthur H, Breen M.Eleven apparent mutations of the equine plasma transferrin and esterase gene (10 in TF and one in ES) were found in an analysis of approximately 240,000 thoroughbred horses. Eight of the transferrin mutations produced variants not previously recognized in horses. In the two remaining transferrin mutations and the esterase mutation, reduced plasma concentrations of the proteins were demonstrated by immunological techniques and together with the family data indicated the existence of 'null' alleles.
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...
Blikslager AT, Roberts MC.To assess the ability of clinicians to predict the site and type of lesion as well as outcome in horses with colic. Methods: Prospective case study. Methods: 139 horses admitted for evaluation of signs of colic. Methods: Six interns and residents examined horses with colic and predicted the segment of intestine that was affected, the type of lesion, and whether the horse would survive to discharge. Accuracy of prediction of site and type of lesion and survival prediction was compared between the first and second halves of the year, using chi 2 analysis and 95% confidence intervals on sensitivi...
Sojka JE, Levy M.This article outlines strategies on how to approach equine endocrine disorders based on clinical signs and clinical pathologic data. In the 1987 Veterinary Clinics of North America: Equine Practice article on evaluating equine endocrine function, Beech stated that the numbers of hormonal assays available to use in horses was limited. Unfortunately, not much has changed since then. With the advent of convenient assay kits for many hormones and cofactors available in human medicine, it is possible to submit samples to laboratories for measurement of a wide range of endogenous substances. Caution...
Swiderski CE, McClure JJ.The immune system is a complex interactive network. Defects in its function can be characterized broadly as being the result of actual deficiencies in the network or misdirection of normal immunologic functions. The assays that are available to detect deficiencies in the immunologic network barely scrape the surface of the possibilities. These assays primarily evaluate humoral immune function, but undetected defects in innate and cellular immunity are sure to exist. Although assays of humoral immunity have allowed the characterization of a number of immunodeficiency syndromes in horses, closer...
Cogswell AM, Johnson PJ, Adams HR.To test the hypothesis that endothelium-derived nitric oxide modulates vasomotor reactivity in equine digital arteries. Methods: Digital arteries were isolated from adult horses, and their vasodilator properties were examined in an in vitro controlled environment. Methods: Five adult horses (1 gelding, 4 mares) without evidence of hoof or vascular disease were studied. Methods: Arterial rings with or without endothelium were exposed to endothelium-dependent vasodilator drugs in the presence or absence of a pharmacologic inhibitor of the enzyme nitric oxide synthase. Results: Vasodilator effect...
Maeda Y, Ohtsuka H, Tomioka M, Tanabe T, Nambo Y, Uematsu H, Oikawa MA.Escherichia coli(E. coli) isolated from the uterus of a Thoroughbred mare with bacterial endometritis was used to evaluate the effect of progesterone (P(4)) on the immune response of mares. Peripheral blood mononuclear cells (PBMCs) were collected from 10 nonpregnant clinically healthy adult mares (range, 4-12 years) during diestrus, four Thoroughbreds and six Hokkaido native horses. Cell proliferation and expression of cytokine mRNA, including interferon (IFN)-γ, tumor necrosis factor (TNF)-α and interleukin (IL)-10, of PBMCs stimulated with E. coli and P(4) were examined in vitro. P(4) was...
Morrison S.Laminitis is a disease of the suspensory apparatus of the distal phalanx, which can advance to the chronic stage with varying degrees of structural failure. Because the disease may ultimately lead to mechanical failure of the digit, a foot management plan is required to effectively and mechanically treat these cases. Many laminitis cases can be successfully rehabilitated back to athletic soundness, light use, breeding, or pasture soundness, whereas others suffer from permanent instability and never enjoy an acceptable level of comfort. To understand how to minimize damage in the acute laminiti...
Raizner NT, Gedon NKY, Zablotski Y, Kania SA, Kühnle HF, Kühnle C, Mueller RS.Equine pastern dermatitis (EPD) is a common multifactorial clinical syndrome in horses. Treatment can be difficult; pathogenesis and triggering factors cannot always be determined. Objective: To assess risk factors for developing EPD in a large group of horses kept under the same conditions and to analyse whether or not a spot-on containing essential fatty acids and antimicrobial agents is able to prevent the development of EPD or accelerate the healing process. Methods: Each year 50 young, privately owned, warmblood horses were prospectively included. Methods: All horses were examined weekly ...
Merchan A, Barrett EJ, Rodgerson DH.A technique for hand-assisted laparoscopic removal of cystic calculi in male horses is described. Three cystic calculi ranging from 5 to 10 cm in diameter were removed successfully using bilateral para-inguinal laparoscopic portals assisted by a human hand within the abdomen, effectively sealing the midline incision. Long-term follow-up information obtained from referring veterinarians and owners indicated that the patients returned to their previous activity level and had no recurrence of clinical signs in the following 6 to 12 months. Key clinical message: Hand-assisted recumbent laparoscopy...
Harvey CE.Dental procedures have been performed on animals, particularly horses, since earliest recorded history. In the absence of anesthesia and an understanding of physiology and pathology, treatment often was unnecessary, inappropriate or barbaric. Progress was made very slowly.
Meier AD, de Laat MA, Reiche DB, Sillence MN.Endocrinopathic laminitis, related to equine metabolic syndrome and insulin dysregulation, causes marked pain and suffering in horses and represents a substantial cost to the horse industry. This study investigated the effect of feeding a diet high in nonstructural carbohydrates on concentrations of active glucagon-like peptide-1 (aGLP-1), total insulin-like growth factor-1 (IGF-1), and high-molecular-weight (HMW) adiponectin, in insulin-dysregulated ponies. Thirty-seven ponies were challenged with this diet for up to 18 d to induce hyperinsulinemia. Hormone concentrations were measured in se...
Horohov DW.The ultimate reason for better characterizing the immune response to infectious agents is the hope that this knowledge may lead to the development of better preventative or therapeutic measures. As more information becomes available, it becomes possible to incorporate these findings into the design of better vaccines and treatments. Likewise, attempts to either enhance or suppress specific helper T-cell responses may be required to control immunopathologic reactions. Although cytokine intervention in the clinical setting remains theoretic at this time, future manipulation based on the TH1/TH2 ...
Ireland FA, Loch WE, Worthy K, Anthony RV.Pregnant pony mares in Group A (n = 4) received i.m. injections at 07:00 and 17:00 h of 0.8 mg bromocriptine/kg body weight 0.75 per day beginning on Day 295 of gestation and continuing until parturition. Group B (n = 4) was treated similarly, but perphenazine was administered orally at 0.375 mg/kg body weight twice a day beginning on Day 305 of gestation and continuing until parturition. Mares in Group C (n = 3) received i.m. injections of saline. Mean plasma prolactin and progesterone concentrations were greater (P less than 0.05) for mares in Group C than in Groups A and B from 295 to 309 d...
Pauli B, Althaus S, Von Tscharner C.Migrating fourth-stage larvae of Strongylus vulgaris, a parasite of equines, damage the intima of the anterior mesenteric artery and its larger branches and induce thrombus formation on the injured sites. As the time of larval passage through each of these branches has been exactly determined in earlier experiments, the aim of the present studies is to contribute to a more complete understanding of repair mechanisms in the process of time after thrombotic vascular injuries. Methods: five foals were separated individually to specially cleaned stables and given anthelmintic treatment till the ag...