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.
Liu IK, Troedsson MH.Diagnosis and treatment of endometritis in the mare has been controversial and mostly empirical. The lack or inability of researchers to establish or develop a model that can serve as a standard or control makes this area of equine reproduction difficult to address scientifically. However, major advances have been made, particularly with the demonstration of the importance of uterine contractility in the elimination of bacteria, fluid, and inflammatory products from the uterus after breeding. This review provides a historical perspective of what has been done, and where we are now, in the appr...
Araújo JA, Curcio B, Alda J, Medeiros RM, Riet-Correa F.Two outbreaks of Hypochaeris radicata-induced Australian stringhalt involving two farms and seven horses from southern Brazil are reported here. Subsequently, the disease was experimentally reproduced in a feeding trial with one colt fed H. radicata from the suspect paddocks. Fresh H. radicata was fed to the experimental animal for 50 days at an average daily dosage of 9.8 kg. Initially, the plant was collected from the paddock where the clinical disease occurred and was fed for 19 consecutive days producing mild clinical signs. However, on days 20-23 fresh plant was collected from a neighbori...
Holyoak GR, Balasuriya UB, Broaddus CC, Timoney PJ.Recently, there has been increased interest in equine viral arteritis (EVA) among veterinarians and horse owners. Outbreaks of the disease were identified initially in New Mexico, USA in 2006, and in the Normandy region of France in the summer of 2007. Both occurrences were associated with AI of cool-shipped semen. Each was linked to respiratory illness, neonatal death, abortion, development of carrier stallions, and cancellation of equestrian events. In light of the increased interest, this paper will present a brief case history, followed by a review addressing common concerns regarding EVA,...
Wagner B, Hillegas JM, Flaminio MJ, Wattrang E.Interferon-alpha (IFN-alpha) is a type I interferon that is secreted during the early stages of the innate immune response and is often induced upon infection with viral pathogens. IFN-alpha production affects multiple downstream events influencing both innate and adaptive immune responses. Here, we describe the expression of an equine rIFN-alpha/IgG4 fusion protein in mammalian cells. The anti-viral activity of rIFN-alpha/IgG4 was found to be 70-fold higher than that of a previously described IFN-gamma/IgG1 as tested by bioassay. The purified rIFN-alpha was subsequently used for the generatio...
Chang M, Overk CR, Kastrati I, Peng KW, Yao P, Qin ZH, Petukhov P, Bolton JL, Thatcher GR.Oxidative metabolism of estrogens has been associated with genotoxicity. O-methylation of catechol estrogens is considered as a protective mechanism. 4-Methoxyequilenin (4-MeOEN) is the O-methylated product of 4-hydroxyequilenin (4-OHEN). 4-OHEN, the major catechol metabolite of the equine estrogens present in the most widely prescribed hormone replacement therapeutics, causes DNA damage via quinone formation. In this study, estrogen receptor (ERa) binding of 4-MeOEN was compared with estradiol (E2) and equilenin derivatives including 4-BrEN using computer modeling, estrogen response element (...
Scocco P, Pedini V.This study was performed to identify the equine respiratory tract areas which express the specific receptor for equine influenza virus; findings may be useful to provide new ways to treat the infectious disease. The present work aims to visualize in situ the presence of sialoderivatives in the horse respiratory tract in order to localize sialoderivatives acting as influenza virus receptors. To this purpose, nasal mucosae, trachea, bronchus and lung parenchyma were removed from 8 mature horses of both sexes. We performed sialic acid characterization by means of mild and strong periodate oxidati...
Gehlen H, Oey L, Rohn K, Bilzer T, Stadler P.Chronic pulmonary diseases (recurrent airway obstruction [RAO]) have been reported to alter skeletal muscle cells in humans. The purpose of this study was to evaluate a potential relationship between pulmonary and muscle variables in horses with a clinical diagnosis of RAO. Muscle biopsies from healthy horses and from horses with RAO were investigated and the relationship between the severity of lung disease and the degree of muscular changes was determined. Objective: We hypothesized that chronic pulmonary disease can lead to changes of the skeletal muscle in horses. Methods: Fifteen healthy ...
Ryhner T, Müller N, Balmer V, Gerber V.The mechanisms leading to mucus accumulation in equine inflammatory airway disease (IAD) and recurrent airway obstruction (RAO) are unclear. In airways of human patients with asthma and/or chronic obstructive pulmonary disease as well as in animal models of these diseases, associations of mucus hyperproduction with increased calcium-activated chloride channel 1 (CLCA1), epidermal growth factor receptor (EGFR), mucin 5AC (MUC5AC), B-cell lymphoma 2 (Bcl-2), interleukin (IL)-13 and interferon (IFN)-gamma expression have been reported. We hypothesized that increased mucus accumulation in RAO and ...
Perelygin AA, Zharkikh AA, Astakhova NM, Lear TL, Brinton MA.Chemokine receptors (CCRs) play an essential role in the initiation of an innate immune host response. Several of these receptors have been shown to modulate the outcome of viral infections. The recent availability of complete genome sequences from a number of species provides a unique opportunity to analyze the evolution of the CCR genes. A phylogenetic analysis revealed that the CCR2 gene evolved in concert with the paralogous CCR5 gene, but not with another paralogous gene, CCR3, in the opossum, platypus, rabbit, guinea pig, cat, and rodent lineages. In addition, evidence of concerted evolu...
Mele M, Ramseyer A, Burger D, Brehm W, Rieder S, Marti E, Straub R, Gerber V.Many of the important diseases of sport and pleasure horses are thought to have a genetic component. The majority of these diseases, however, are multifactorial and are influenced not only by genetics, but also by environmental factors. In this review some of the most important multifactorial diseases are described and the current evidence for a genetic background is discussed.
Mele M, Ramseyer A, Burger D, Leeb T, Gerber V.Overall, monogenetic hereditary diseases are less important for the breeding industry than polygenetic diseases because they are relatively rare. For the individual animal, however, these diseases have often a dramatic outcome and many of these diseases presently known are lethal. For several of them the exact pathogenesis is known and DNA-tests are available to confirm the exact diagnosis.
Govaere JL, Hoogewijs MK, de Schauwer C, Dewulf J, de Kruif A.Embryo reduction of unilateral twin vesicles is normally successful before fixation of the vesicles. After fixation, however, it becomes a challenge, and the later in the gestation period that the reduction is performed, the greater the challenge. One therapy to reduce a twin into a singleton pregnancy is the transvaginal ultrasound-guided aspiration (TUGA) of one of the vesicles. The results of 35 unilateral twin reductions by TUGA are discussed in this paper and possible negative influences of age, parity and days pregnant are analysed statistically.
Lichtenfels JR, Kharchenko VA, Dvojnos GM.The Equidae (the horse, Equus caballus, the ass, Equus asinus, zebras and their hybrids) are hosts to a great variety of nematode parasites, some of which can cause significant morbidity or mortality if individual hosts are untreated. Worldwide the nematode parasites of horses belong to 7 suborders, 12 families, 29 genera and 83 species. The great majority (19 of 29 genera and 64 of 83 species) are members of the family Strongylidae, which includes the most common and pathogenic nematode parasites of horses. Only the Strongylidae are included in this treatise. The Strongylidae (common name str...
De Botton D, Janett F, Burger D, Imboden I, Kähn W, Thun R.The aim of the present study was to investigate the spermatogenic and Leydig cell activity in stallions with impaired semen quality after treatment with equine somatotropin. Experiments were performed using 18 adult clinically healthy stallions with poor semen quality which did not pass breeding soundness evaluation. The animals were randomly divided into a treatment (n = 9) and a control (n = 9) group. Over a period of 90 days, nine stallions received a daily intramuscular injection of 10 mg recombinant equine somatotropin (EquiGen, BresaGen Limited, Adelaide, Australia) and 9 control animals...
Archer DC, Pinchbeck GL, French NP, Proudman CJ.Epiploic foramen entrapment (EFE) is a common cause of small intestinal strangulation in the horse and its epidemiology requires further investigation. Objective: To identify horse- and management-level risk factors for EFE and to explore reasons for the apparent seasonality of this condition. Objective: Horses exhibiting certain behaviours and those exposed to particular management practices that vary seasonally are at increased risk of EFE. Methods: A prospective unmatched, multicentre case-control study was conducted over 24 months in the UK. Data on 77 cases and 216 control horses were obt...
Hudson NP, Merritt AM.Equine gastrointestinal motility is a central issue in cases of equine colic, post operative convalescence and alimentary conditions encountered in practice. There are significant syndromes of intestinal dysmotility in the horse such as obstructive disorders and post operative ileus that are still poorly understood. This review describes the various areas of research that aim to elucidate the pathogenesis of intestinal hypo- or hypermotility by research methods, which include studies at the cellular level, and those that employ in vitro or in vivo techniques of evaluating the physiology and me...
Williams KJ, Derksen FJ, de Feijter-Rupp H, Pannirselvam RR, Steel CM, Robinson NE.Exercise-induced pulmonary hemorrhage (EIPH) is common in horses following intense exertion, occurring in up to 75% of racing Thoroughbreds and Standardbreds. In spite of this, the pathogenesis of EIPH is poorly understood. In 7 racing Thoroughbred horses with EIPH, 6 sections were collected from the left and right lung, representing the cranial, middle, and caudal region of the dorsal and ventral lung (84 sites total). Grossly, both right and left lungs had numerous dark brown to blue-black foci along the caudodorsal visceral pleura. Tissue sections were stained with hematoxylin-eosin, Masson...
Mäkinen PE, Archer DC, Baptiste KE, Malbon A, Proudman CJ, Kipar A.Idiopathic focal eosinophilic enteritis (IFEE) and diffuse eosinophilic enteritis (DEE) are primary eosinophilic intestinal conditions without a known cause that are associated with an increasing number of surgical colic cases. Histology may be helpful in defining disease aetiology and pathogenesis. Objective: To characterise further the inflammatory infiltrate in equine IFEE and to compare the condition with DEE. Methods: Twenty-three IFEE cases and 5 DEE cases were examined by light microscopy including immunohistology to identify infiltrating leucocytes. Inflammatory infiltrates in mucosa a...
Grosche A, Morton AJ, Polyak MM, Matyjaszek S, Freeman DE.The cytosolic protein complex, calprotectin, is abundant in neutrophils and could be used to improve the ability to localise and assess neutrophil infiltration in the equine intestine during ischaemia and reperfusion (I/R), but further study is required. Objective: To assess the number of calprotectin-containing cells by immunohistochemistry in correlation with direct counting and scoring of neutrophils in the equine colon during I/R. Methods: One and 2 h ischaemia of the left dorsal colon were induced, followed by 30 min reperfusion under general anaesthesia or by 18 h reperfusion after anaes...
Olstad K, Ytrehus B, Ekman S, Carlson CS, Dolvik NI.The developmental pattern of the cartilage canal blood supply to epiphyseal growth cartilage has been linked to osteochondrosis (OC) in the tarsus of foals. This pattern has not yet been described in the distal femur, another site frequently affected by OC. Objective: To describe the developmental pattern of the blood supply to the distal femoral epiphyseal growth cartilage in 8 Standardbred foals age 0-7 weeks. Methods: One foal was sacrificed weekly from birth to age 7 weeks (n=8) to undergo a barium perfusion procedure to demonstrate vessels within cartilage canals of one hindlimb. The dist...
Thomason JJ, Faramarzi B, Revill A, Sears W.Differences in hoof morphology have largely been underappreciated in the literature until recently, and it is these that hold the key to interpreting functional adaptation in the hoof. Objective: Primary laminar morphology correlates with hoof capsule shape; and breeds with different hoof shapes and loadings show different patterns of correlation. Methods: Seventeen measurements of capsule shape and 3 of primary epidermal laminae (PEL) morphology (spacing, orientation and curvature) were made on right and left front hooves from 27 Standardbred and 25 Thoroughbred horses, and tested for breed d...
Shirazi-Beechey SP.Equine colic, a disorder manifested in abdominal pain, is the most frequent cause of emergency treatment and death in horses. Colic often requires intestinal surgery, subsequent hospitalisation and post operative care, with a strong risk of complications arising from surgery. Therefore strategies that explore approaches for preventing the condition are essential. To this end, a better understanding of the factors and mechanisms that lead to the development of colic and related intestinal diseases in the horse allows the design of preventive procedures. Colic is a multifactorial disorder that a...
Lecocq M, Girard CA, Fogarty U, Beauchamp G, Richard H, Laverty S.The earliest osteochondrosis (OC) microscopic lesion reported in the literature was present in the femorotibial joint of a 2-day-old foal suggesting that OC lesions and factors initiating them may arise prior to birth. Objective: To examine the developing equine epiphysis to detect histological changes that could be precursors to OC lesions. Methods: Osteochondral samples from 21 equine fetuses and 13 foals were harvested from selected sites in the scapulohumeral, humeroradial, metacarpophalangeal, femoropatellar, femorotibial, tarsocrural and metatarsophalangeal joints. Sections were stained ...
Dyson S, Blunden T, Murray R.Magnetic resonance imaging (MRI) is used with increasing frequency to diagnose injuries of the collateral ligaments (CLs) of the distal interphalangeal (DIP) joint, but the results have not been verified by histology and the mechanism of injury is poorly understood. Objective: Abnormal signal intensity and tissue contour represents change in tissue structure detected on histology. Objective: To compare results in horses free from and those with chronic lameness and to describe possible progression of lesions. Methods: One or both feet of horses free from lameness (Group N: n = 12) and with foo...
Ueti MW, Palmer GH, Scoles GA, Kappmeyer LS, Knowles DP.Tick-borne pathogens may be transmitted intrastadially and transstadially within a single vector generation as well as vertically between generations. Understanding the mode and relative efficiency of this transmission is required for infection control. In this study, we established that adult male Rhipicephalus microplus ticks efficiently acquire the protozoal pathogen Babesia equi during acute and persistent infections and transmit it intrastadially to naïve horses. Although the level of parasitemia during acquisition feeding affected the efficiency of the initial tick infection, infected t...
Norman TE, Chaffin MK, Perris EE, Edwards JF, David JB, Cohen ND, Reuss S.This report involves 6 cases in which medical records and post mortem findings were reviewed leading to the diagnosis of massive pulmonary thromboembolism (MPTE). All horses were mature and MPTE has not been recognised previously as a sequel to generalised systemic illness in mature horses. The clinical data and pathological findings of the cases are reported and the authors conclude that MPTE is an uncommon but important complication of medical and surgical disorders in mature horses. In 3 of the cases, the condition was nonfatal suggesting that some horses having developed PTE survive and th...
Durham AE, Rendle DI, Newton JE.Laminitis in equids is a very common debilitating disease, and insulin resistance (IR) and hyperinsulinaemia are increasingly recognised as important predisposing factors. Pharmacological modification of IR and hyperinsulinaemia might reduce the risk of laminitis. Objective: Metformin, a drug commonly prescribed for treatment of human IR, may also decrease IR in equids. Methods: Eighteen horses and ponies with IR and recurrent laminitis were treated with 15 mg/kg bwt metformin per os q. 12 h. Each animal served as its own control by comparing pre- and post treatment proxies for IR, insulin sen...
Hillyer MH, Smith MR, Milligan PJ.Ileus (functional obstruction of aboral gastrointestinal transit) is an uncommon cause of gastrointestinal dysfunction and colic in the horse. A number of specific conditions have been previously reported in association with ileus. This report describes the recognition of primary gastric and small intestinal ileus of undetermined cause in a series of post parturient mares. Objective: To describe the clinical features, treatment and outcome of a series of episodes of primary gastric and small intestinal ileus. Methods: A retrospective study was performed of colic episodes seen in an equine prac...
Audigié F, Pourcelot P, Degueurce C, Geiger D, Denoix JM.This study was undertaken to describe the symmetry of movements of fore- and hindlimbs in horses suffering from various spontaneous lamenesses. Two groups of horses were studied: 13 clinically sound horses and 24 lame horses. Using a 3-dimensional (3-D) kinematic analysis system, movements of both sides of each horse were recorded simultaneously while trotting on a track. The differences in motion between left and right homologous joints of each horse were quantified using symmetry indices based on an intercorrelation method. Symmetry indices obtained for each lame horse were then compared wit...
Wylie CE, Proudman CJ, McGorum BC, Newton JR.Equine grass sickness (EGS) remains a frequently fatal disease of equids in Great Britain (GB). The first nationwide surveillance scheme for EGS was developed to obtain information on the occurrence of EGS and to help facilitate future proposed intervention studies, such as vaccine trials. Objective: To collect both retrospective and prospective data on cases of EGS occurring in GB since 2000 and to assess potential risk factors for categories of EGS and survival after chronic EGS. Methods: Prospective data were collected using a nationwide surveillance scheme for EGS that was developed and in...
Duncan JL, Abbott EM, Arundel JH, Eysker M, Klei TR, Krecek RC, Lyons ET, Reinemeyer C, Slocombe JO.These guidelines have been designed to assist in the planning, operation and interpretation of studies which would serve to assess the efficacy of drugs against internal parasites of horses. Although the term anthelmintic is used in the title and text, these guidelines include studies on drug efficacy against larvae of horse bot flies, Gasterophilus spp., which are non-helminth parasites commonly occurring in the stomach of horses. The advantages, disadvantages and application of critical and controlled tests are presented. Information is also provided on selection of animals, housing, feed, d...
Rumpler MJ, Sams RA, Colahan P.A rapid, sensitive, and specific ultra-high-performance liquid chromatography with heated electrospray ionization-tandem mass spectrometry (UHPLC-HESI-MS-MS) method to detect and quantify glycopyrrolate in horse plasma has been developed and validated. We also determined glycopyrrolate in plasma after oral and intravenous administration of clinically relevant doses to Thoroughbred horses. Calibration was accomplished by weighted, linear regression analysis using a deuterated analogue of glycopyrrolate as internal standard (IS). Glycopyrrolate (GLY) and the IS (GLY-d(3)) were isolated from plas...
Yoon J, Park T, Kim A, Park J, Park BJ, Ahn HS, Go HJ, Kim DH, Jung S, Seo Y, Lee JB, Park SY, Song CS, Lee SW, Choi IS.Equine parvovirus-hepatitis (EqPV-H) is a newly identified etiologic agent of Theiler's disease (TD). We present a case of EqPV-H-related fulminant hepatitis in a 14-year-old thoroughbred mare in Korea. The mare had acute hepatopathy and gastrointestinal symptoms, with abnormal liver-related blood parameters. The horse was born in the USA and imported to Korea in 2017, with no history of administration of equine biological products after entry into Korea. The horse was diagnosed with EqPV-H-associated hepatitis after abdominal ultrasonography, laparotomy, and nested polymerase chain reaction (...
Butler CM, van Gils JA, van der Kolk JH.Piroplasmosis, a disease endemic to most tropical and subtropical areas, appears to be spreading to more temperate zones. This article gives a review of equine piroplasmosis and describes an acute case of infection with Babesia caballi in a Dutch Standard bred foal after a short stay at a stud in Normandy (France). A 3-month-old stallion foal was presented with lethargy, fever of 41 degrees C, and pale mucosal membranes. Haematology revealed a low packed cell volume (14 l/l) leucytosis (25 G/l) and a high blood urea nitrogen concentration (20.1mmol/l). Infection with B. caballi was diagnosed o...
Duggan VE, Holyoak GR, MacAllister CG, Cooper SR, Confer AW.The objective of this study was to investigate the protein, amyloid A3 (AA3), in equine colostrum and early milk. We hypothesized that AA3 was consistently present in equine colostrum and early milk, that no correlation existed between serum and colostrum concentrations of this protein in individual mares at parturition and that colostrum/milk concentrations of this mammary protein may be affected by age, breed, length of gestation and/or induction of parturition. Thirty-eight peripartum mares and seven non-pregnant, non-lactating mares were included in the study. Mean serum concentrations of ...
Tarancón I, Armengou L, Melendez-Lazo A, Pastor J, Ríos J, Jose-Cunilleras E.To assess the prevalence of exercise-induced pulmonary hemorrhage (EIPH) among elite endurance horses after competition in a long-distance race. 20 endurance horses and 12 nonexercised or minimally exercised age-, breed-, and trainer-matched horses from the same environment (control horses). Bronchoalveolar lavage fluid samples collected from endurance horses at 3 to 8 days (sample A) and 36 to 38 days (sample B) after the race (100 km in 1 day [n = 3], 70 km/d for 2 days [12], or 100 km/d for 2 days [5]) were cytologically examined for the presence of hemosiderophages. Samples from control ho...
Ribera T, Monreal L, Delgado MA, Ríos J, Prades M.To assess the synovial fibrinolytic pathway activation in adult horses with developmental and degenerative arthropathies such as osteochondritis dissecans (OCD) and osteoarthritis (OA) by measuring synovial D-dimer concentrations. Methods: Prospective observational clinical study of horses admitted for OCD or OA. Synovial fluid was collected during lameness examination or prior to the surgical procedure, and D-dimer concentration and routine synovial fluid analysis were performed. Results: Fifty-eight horses (14 with OCD, 10 with OA and 34 controls) were included in this study. Synovial D-dime...
Portela DA, Di Franco C, Chiavaccini L, Araos J, Romano M, Otero PE, Biedrzycki AH, Schramel JP.To evaluate the impact of a 30% end-inspiratory pause (EIP) on alveolar tidal volume (V), airway (V) and physiological (V) dead spaces in mechanically ventilated horses using volumetric capnography, and to evaluate the effect of EIP on carbon dioxide (CO) elimination per breath (Vcobr), PaCO and the ratio of PaO-to-fractional inspired oxygen (PaO:FiO). Methods: Prospective research study. Methods: A group of eight healthy research horses undergoing laparotomy. Methods: Anesthetized horses were mechanically ventilated as follows: 6 breaths minute, tidal volume (V) 13 mL kg, inspiratory-to-expir...
Lafortuna CL, Saibene F, Albertini M, Clement MG.Horses display remarkable aerobic capabilities, attaining during muscular exercise a maximal rate of oxygen consumption about 30-fold higher than the resting value, and 2.5-fold higher than that of other mammals of similar body mass. Under these circumstances an enormous mechanical burden is expected to impinge on the equine respiratory pump and regulatory mechanisms aiming to minimize this load may play an important role in determining the adequacy of the respiratory system to the metabolic requirements. The behaviour of the respiratory system has been investigated in horses at rest and durin...
Blythe LL, Cardinet GH, Meagher DM, Brown MP, Wheat JD.The histologic and histochemical features of palatine muscles from 53 horses were studied; 25 of the horses were racehorses that had upper airway obstruction associated with dorsal displacement of the soft palate and 28 of the horses did not have any respiratory disorders and served as controls. Pathologic features observed included myonecrosis, phagocytosis, mononuclear cell infiltration of perimysial connective tissue, alkaline phosphatase-positive myofibers, and myofibers with cytoarchitectural changes that included irregular staining of the intermyofibrillar sarcoplasm and sarcoplasmic mas...
Schwarz B, Ertl R, Zimmer S, Netzmann Y, Klein D, Schwendenwein I, Hoven RV.The aim of this study was to determine the occurrence and frequency of a mutation in the gene coding for skeletal muscle glycogen synthase type 1 (GYS-1), which is the cause of equine polysaccharide storage myopathy (PSSM) type 1 in a population of 50 Haflingers. GYS-1 genotyping of 50 Haflingers was performed with a validated restriction fragment length polymorphism (RFLP) assay. The second aim was to compare resting and post-exercise muscle enzyme activities as well as parameters of glucose metabolism in blood between horses with and without the mutation. Nine of the 50 Haflingers were ident...
Wilson GJ, Walsh LJ.To quantify the temperature changes in the dental pulp associated with equine dental procedures using power grinding equipment. Methods: A matrix experimental design with replication on the same sample was followed to allow the following independent variables to be assessed: horse age (young or old), tooth type (premolar or molar), powered grinding instrument (rotating disc or die grinder), grinding time (15 or 20 seconds) and the presence or absence of water coolant. Methods: Sound premolar and molar teeth from a 6-year-old horse and a 15-year-old horse, which had been removed postmortem, wer...
Loynachan AT, Bolin DC, Hong CB, Poonacha KB.Hepatoblastoma was diagnosed in 3 Thoroughbreds at the University of Kentucky Livestock Disease Diagnostic Center (LDDC) since 1997. Case #1 involved a fetus with a well-demarcated, multilobulated, solitary mass that extended from the left liver lobe. Case #2 was observed in a neonate with a primary hepatic mass and multiple metastases in the skin, brain, meninges, and stylohyoid bone. Case #3 was a solitary hepatic mass incidentally discovered in a neonate at necropsy. Microscopically, the masses were similarly composed of sheets and cords of fetal and embryonal epithelial cells that frequent...
Griffiths IR, Kyriakides E, Smith S, Howie F, Deary AW.Equine grass sickness (EGS) is a primary dysautonomia characterised pathologically by lesions in autonomic ganglia, enteric plexi and specific nuclei in the CNS. Immunocytochemistry and lectin histochemistry of the autonomic ganglia were used to determine whether abnormalities can be detected in specific proteins or cellular organelles. EGS ganglia contained a mixture of morphologically normal and abnormal neurons, the former appearing identical to cells from control animals. Affected cells showed marked disturbances in neurofilament (NF) proteins and beta-tubulin, major components of the cyto...
Ledbetter EC, Irby NL.To describe the corneal in vivo confocal microscopy (IVCM) findings in horses with putative immune-mediated keratitis (IMMK). Methods: Sixty five horses with IMMK. Methods: Horses diagnosed with IMMK were examined with a modified Heidelberg Retina Tomograph II and Rostock Cornea Module. The findings from the IVCM examinations were correlated with clinical details from ophthalmic examination and diagnostic test results. Results: Eighty eyes from 65 horses were examined. Clinical IMMK lesions were categorized as epithelial (n = 17 eyes), superficial stromal (n = 38), midstromal (n = 18), a...
Parks AH.Therapeutic shoeing is best directed at a specific diagnosis, but in the absence of a specific diagnosis, it is frequently directed at a symptom. There are only so many ways to modify the function of the foot with trimming and shoeing. The design of a horse shoe may often be modified to improve one aspect of foot function. Modifying a horse shoe to improve one aspect of foot function almost invariably impacts another aspect of foot function. The application of horse shoes may be based on a specific diagnosis or directed at a symptom. The application of shoeing principles is best approached usi...
Pearce SG, Hurtig MB, Boure LP, Radcliffe RM, Richardson DW.To investigate the feasibility of resurfacing the equine fetlock joint using cylindrical, orthotopic, press-fit, osteochondral allografts. Methods: Experimental study. Methods: Ten mature, mixed-breed horses. Methods: Cylindrical, osteochondral grafts (6.5-mm diameter) were harvested aseptically from cadaveric equine metatarsophalangeal joints. Allografts were transplanted into 6 horses; 4 horses were sham operated. The surgical approach involved creation of a bone block at the origin of the medial collateral ligament and luxation of the metatarsophalangeal joint. Grafts were placed into the m...
Zamboulis DE, Senior M, Clegg PD, Milner PI.Tissue sensitisation and chronic pain have been described in chronic-active laminitis in the horse, making treatment of such cases difficult. Purinergic P2X receptors are linked to chronic pain and inflammation. The aim of this study was to examine the expression of purinergic P2X receptor subtypes 1, 2, 3 and 7 in the hoof, palmar digital vessels and nerve, dorsal root ganglia and spinal cord in horses with chronic-active laminitis (n=5) compared to non-laminitic horses (n=5). Immunohistochemical analysis was performed on tissue sections using antibodies against P2X receptor subtypes 1-3 and ...
Robinson C, Heather Z, Slater J, Potts N, Steward KF, Maskell DJ, Fontaine MC, Lee JJ, Smith K, Waller AS.Strangles, caused by Streptococcus equi subspecies equi (S. equi) is one of the most frequently diagnosed infectious diseases of horses and there remains a significant need to develop new preventative vaccines. We generated a live vaccine strain of S. equi containing deletions in six genes: sagA, hasA, aroB, pyrC, seM and recA, which was administered to nine Welsh mountain ponies via the intramuscular route. Four vaccinated ponies developed adverse reactions following the first vaccination from which the live vaccine strain was isolated. Two of these ponies were withdrawn from the study and se...
Cummings CO, Krucik DDR, Price E.Clinical predictive models use a patient's baseline demographic and clinical data to make predictions about patient outcomes and have the potential to aid clinical decision making. The extent of equine clinical predictive models is unknown in the literature. Using PubMed and Google Scholar, we systematically reviewed the predictive models currently described for use in equine patients. Models were eligible for inclusion if they were published in a peer-reviewed article as a multivariable model used to predict a clinical/laboratory/imaging outcome in an individual horse or herd. The agreement o...
Nieto JE, Maher O, Stanley SD, Larson R, Snyder JR.To determine the effects of domperidone on in vivo and in vitro measures of gastrointestinal tract motility and contractility in healthy horses. Methods: 18 adult horses and tissue samples from an additional 26 adult horses. Methods: Domperidone or placebo paste was administered to healthy horses in a 2-period crossover study. Gastric emptying was evaluated after oral administration of domperidone paste (1.1 or 5.0 mg/kg) or placebo paste by means of the acetaminophen absorption test in 12 horses. Frequency of defecation, weight of feces produced, fecal moisture, and stomach-to-anus transit ti...
Sievers J, Distl O.Chronic progressive lymphedema (CPL) is a common disease in Rhenisch German draught horses. The objective of our study was to evaluate the prevalence of this disease and its progression with age in 493 Rhenish German draught horses from different regions in Germany. We employed generalized linear models with binomial, multinomial, and normal distributions to analyse the effects of breeding association, coat colour, sex and age within sex, time of examination, limb on which CPL was recorded, and farm-related factors on disease scores. The occurrence and severity of CPL were significantly influe...
Castaneda C, Radović L, Felkel S, Juras R, Davis BW, Cothran EG, Wallner B, Raudsepp T.Structural rearrangements like copy number variations in the male-specific Y chromosome have been associated with male fertility phenotypes in human and mouse but have been sparsely studied in other mammalian species. Here, we designed digital droplet PCR assays for 7 horse male-specific Y chromosome multicopy genes and SRY and evaluated their absolute copy numbers in 209 normal male horses of 22 breeds, 73 XY horses with disorders of sex development and/or infertility, 5 Przewalski's horses and 2 kulans. This established baseline copy number for these genes in horses. The TSPY gene showed the...
Wetmore LA, Pascoe PJ, Shilo-Benjamini Y, Lindsey JC.OBJECTIVE To determine the locomotor response to the administration of fentanyl in horses with and without the G57C polymorphism of the μ-opioid receptor. ANIMALS 20 horses of various breeds and ages (10 horses heterozygous for the G57C polymorphism and 10 age-, breed-, and sex-matched horses that did not have the G57C polymorphism). PROCEDURES The number of steps each horse took was counted over consecutive 2-minute periods for 20 minutes to determine a baseline value. The horse then received a bolus of fentanyl (20 μg/kg, IV), and the number of steps was again counted during consecutive 2-...
Ahern BJ, Boston RC, Parente EJ.Mechanical evaluation of a novel alternate laryngoplasty system (ALPS). Methods: Experimental. Methods: Cadaveric horse larynges (n = 10). Methods: Arytenoid and cricoid cartilages were embedded for testing. A novel laryngoplasty system consisting of a metallic anchor, 2 stands of #2 suture material, and a metallic button were evaluated. A traditional laryngoplasty using a single strand of #5 Ethibond was evaluated in parallel. Constructs were evaluated in cyclic testing oscillating from 30 to 50 N for 3600 cycles. Constructs subsequently underwent a single cycle to failure. Distraction during...
Roasa LM, Choi YH, Love CC, Romo S, Varner DD, Hinrichs K.In vitro fertilization (IVF) was performed on in vitro-matured equine oocytes in three experiments. Frozen-thawed sperm were prepared using swim-up separation and heparin treatment. In Experiment 1, fertilization was achieved with sperm from only one frozen ejaculate of four obtained from the same stallion. Within this ejaculate, fertilization rates were higher with fresh media, as compared to media held for 6-8 days before use (39.6% versus 7.3%, respectively; P<0.001). The type of bovine serum albumin used affected fertilization rates (4% versus 39.6%; P<0.001). To determine if IVF rates wer...
Blissitt KJ, Bonagura JD.Thirty-two horses with cardiac murmurs typical of tricuspid, mitral and aortic regurgitation were studied using colour flow Doppler echocardiography. The dimensions and duration of any regurgitant signals, recorded at the cardiac valve suspected as being the site of origin of the murmur, were measured. Results were compared with flow signals described at the valves of normal horses (Blissitt and Bonagura 1995). Horses with murmurs suggestive of tricuspid (n = 8) and aortic (n = 8) regurgitation showed larger regurgitant signals at the tricuspid and aortic valves respectively, than has been rep...
Christmann U, Hite RD, Tan RH, Thatcher CD, Witonsky SG, Werre SR, Buechner-Maxwell VA.To evaluate the phospholipid composition and function of surfactant in horses with recurrent airway obstruction (RAO) at various clinical stages and compare these properties with findings in horses without RAO. Methods: 7 horses with confirmed RAO and 7 without RAO (non-RAO horses). Methods: Pairs of RAO-affected and non-RAO horses were evaluated before, during, and after exposure to hay. Evaluations included clinical scoring, lung function testing, airway endoscopy, and bronchoalveolar lavage fluid (BALF) absolute and differential cell counts. Cell-free BALF was separated into crude surfactan...
