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.
Baintner K, Csapó J.Mare's colostrum was collected and examined for the presence of trypsin inhibitors. It was found to contain a low level of trypsin inhibitor which could be denatured by 2.5% trichloroacetic acid and, therefore, it clearly differs from the acid-resistant colostral inhibitor of Artiodactyla and Carnivora. This finding is exceptional for a species that concentrates IgG in the colostrum and whose newborn absorbs colostral proteins non-selectively by the gut. It appears that the presence of colostral trypsin inhibitor is not essential for the transmission of maternal immunity via the colostrum and ...
Sellon DC, Walker KM, Russell KE, Perry ST, Covington P, Fuller FJ.Equine infectious anemia virus is a lentivirus that replicates in mature tissue macrophages of horses. Ponies were infected with equine infectious anemia virus. During febrile episodes, proviral DNA was detectable, but viral mRNA was not detectable. As cultured blood monocytes from these ponies differentiated into macrophages, viral expression was upregulated. In situ hybridization confirmed that viral transcription occurred in mature macrophages.
Marntell S, Nyman G.The clinical and cardiorespiratory effects of premedication with acepromazine, butorphanol or diazepam in addition to romifidine before induction of anaesthesia with ketamine were studied in 6 horses on 4 random occasions. Administration of romifidine alone or in combination with butorphanol resulted in an increase in arterial blood pressure, accompanied by a significant decrease in heart rate with second-degree atrio-ventricular heart block. Induction of anaesthesia with ketamine returned the heart rate to baseline value, but the arterial blood pressure was significantly increased compared to...
Kirkland KD, Baker GJ, Manfra Marretta S, Eurell JA, Losonsky JM.To document age-related changes in the morphology of the endodontic system, reserve crown, and roots of equine mandibular cheek teeth. Methods: Equine mandibular cheek teeth from horses of various ages were compared, using radiography, x-ray computed tomography, and histologic examinations. Methods: 48 right hemi-mandibles from horses 2 to 9 years old. Methods: Hemi-mandibles were radiographed, imaged by computed tomographic reconstruction, and reformatted. Histologic examination was used to identify and correlate tissue types. Results: Permanent mandibular cheek teeth of the horse, at the tim...
Cornelissen BP, Rijkenhuizen AB, Barneveld A.The sesamoidean nerve branches from the palmar nerve and runs towards the proximal sesamoid bone. To study the structures innervated by this nerve, a technique for blocking it was developed. The effect of this nerve block was determined in ponies with an induced lameness located in the lateral proximal sesamoid bone (5 ponies) or in the distal part of the lateral branch of the suspensory ligament (5 ponies), and in 10 horses with clinical sesamoidosis. A lameness provoked by the implantation of an expansion plug in the proximal sesamoid bone could, to a large extent, be anaesthetized by a sesa...
Meier HP.The genetic predisposition to navicular disease is proven nowadays, but otherwise, etiology and pathogenesis are still unclear. Causal therapy isn't possible and because of the poor prognosis, neurectomy is still of bearing. This operation was performed already 200 years ago, but in the middle of the last century, critical voices have been raised in regard to the surgical procedure and its indication both for medical reasons and breeding. Clear instructions for exclusion of diseased animals from breeding are also older than one hundred years. These facts call for ethic considerations which con...
Waelchli RO, Betteridge KJ.Horse conceptuses collected between Day 11 and Day 18 of pregnancy float in isotonic media. To investigate this phenomenon, blastocyst fluids from 30 conceptuses from 13 mares were analysed for osmolality and for concentrations of Na+, Cl-, K+, glucose, urea and creatinine. In conceptuses from Group A, samples from Day 11 to Day 16 yielded the following results (mean +/- s.e.m.): osmolality, 121.4 +/- 1.5 mOsm kg-1; Na+, 11.0 +/- 2.2 mM; Cl-, 29.3 +/- 2.5 mM; K+, 26.2 +/- 2.6 mM; glucose, 0.6 +/- 0.1 mM; urea, 6.0 +/- 0.6 mM; creatinine, 9.6 +/- 1.1 microM. Between Day 16 and Day 25, the osmol...
Cárdenas S, Gallego M, Valcárcel M, Ventura R, Segura J.A partially automated module for the routine determination of illicit non-steroid antiinflammatory drugs (NSAIDs) in biological fluids from race horses was built, tested, refined, and shown to work. This pretreatment module retains 17 NSAIDs on an Amberlite XAD-2 column before back-elution derivatization with methyl iodide in acetonitrile. Methylated derivatives are manually injected into a gas chromatograph connected to a mass spectrometer. The quantification limits thus achieved are 50-100 ng/mL in 1 mL of urine or plasma. The proposed method is more expeditious than its manual liquid-liquid...
Estberg L, Stover SM, Gardner IA, Johnson BJ, Case JT, Ardans A, Read DH, Anderson ML, Barr BC, Daft BM, Kinde H, Moore J, Stoltz J, Woods LW.To characterize and contrast data from Thoroughbreds that incurred a fatal musculoskeletal injury (FMI; injury resulting in death or euthanasia) during racing or training and data from all California race entrants during a 9-month period in 1991. Methods: Case-control study. Methods: Thoroughbreds that incurred a FMI during racing or training at a California race-meet and all California race entrants from January through June and October through December 1991. Methods: Age and sex were compared with chi 2 and Fisher's exact tests among horses fatally injured while racing and training. A log-li...
Mizobe M, Kondo F, Kumamoto K, Terada T, Nasu H.Rapid and quantitative analytical methods for bilirubin using high-performance liquid chromatography (HPLC) with UV detection were developed for samples from equines at a meat inspection site. Sharp HPLC peaks for bilirubins, unconjugated bilirubin (UCBL) and conjugated bilirubin (CBL), were obtained using a simple mobile phase of methanol:0.5 M Tris-HCl buffer (65:35, v/v, pH 7.4). A variable wavelength detector set at 450 nm, 0.01 AUFS and a recorder set at 4 cm/min were used for detection. Peaks for UCBL and CBL occurred at 7.1 min and 4.9 min, the lower limits of detection ranged between 0...
Soraci A, Jaussaud P, Benoit E, Delatour P.Fenoprofen (FPF) is a chiral non-steroid antiinflammatory drug, marketed as a racemic mixture of its R(-) and S(+) enantiomers. Its stereoselective disposition in humans and animals is due to a chiral inversion converting R(-)FPF into S(+)FPF. The first step of this reaction, which produces an acyl-CoA thioester, is catalysed by an acyl-CoA ligase. A stereospecific high performance liquid chromatography assay was used to study the disposition of FPF enantiomers in four geldings and three male beagle dogs, following intravenous doses of racemic FPF (1 mg/kg in horses), R(-)FPF (0.5 mg/kg in hor...
Buchner HH, Savelberg HH, Schamhardt HC, Barneveld A.The kinematic patterns of head and trunk were studied in horses during induced supporting limb lameness to understand the mechanisms horses use to compensate for lameness and to evaluate different symmetry indices for their significance as lameness indicators. Using the locomotion analysis system CODA-3 the kinematics of 11 clinically nonlame Dutch Warmblood horses were recorded while walking (1.6 m/s) and trotting (3.5 m/s) on a treadmill. A transient lameness model, evoking pressure induced pain on the hoof sole, was used to induce 3 degrees of fore- and hindlimb lameness. Peak vertical disp...
De La Peña-Moctezuma A, Prescott JF, Goodfellow M.Four isolates of Rhodococcus equi, from pneumonic foals, and containing the 85 kb virulence plasmid, a porcine isolate containing an 80 kb plasmid, and their plasmid cured derivatives, were examined for 239 phenotypic properties in an attempt to find characters other than the virulence-associated protein (VapA) which might be encoded by the virulence plasmid in organisms grown at 37 degrees C. Tests chosen included those which have previously given variable results for R. equi isolates, since such variability might be attributed to plasmid curing, and characteristics which have been described ...
Yanai T, Masegi T, Ishikawa K, Sakai H, Iwasaki T, Moritomo Y, Goto N.Cerebral vascular mineralization was found in 12 (60%) of 20 3- to 10-year-old healthy horses collected at an abattoir. It was variable in degree and occurred mostly in the pallidal arteries showing two types of lesions; small globoid bodies along capillaries, and amorphous deposits in the wall of arterioles, small- or medium-sized arteries and veins. Both types were strongly positive for periodic acid-Schiff reaction, and weakly positive for von Kossa's and Berlin blue stains. Elemental analysis of the deposit revealed the presence of large amounts of aluminum, moderate amounts of phosphorus,...
Richter PJ, Kimsey RB, Madigan JE, Barlough JE, Dumler JS, Brooks DL.Ehrlichia equi, a rickettsia described from horses in California 30 yr ago, causes equine granulocytic ehrlichiosis throughout the Americas and possibly Europe. Here, we report experimental transmission of E. equi from infected to susceptible horses through bites of western blacklegged ticks, Ixodes pacificus (Cooley & Kohls). In preliminary field studies, only I. pacificus consistently infested horses and vegetation at 3 locations with contemporary cases of equine ehrlichosis, and in particular, I. pacificus was the only species found attached to all of the infected horses. Exposure to bites ...
Furuoka H, Yamada M, Miyazawa K, Taniyama H, Matsui T.Here were report eosinophilic globular bodies referred to as dense microspheres (DMS), in the brains of normal horse in relation to the ageing process. The characteristic structures of DMS found in the horse were in similar to those previously reported in the human. The DMS were found predominantly in the neuropil of the cerebral cortex, and were shown histochemically to have a proteinaceous content. Electron microscopy showed that the DMS consisted of homogeneous electron-dense material bound by a single membrane and that they were found within the neuronal processes. In addition, immature or...
Bleumink-Pluym NM, ter Laak EA, Houwers DJ, van der Zeijst BA.The ability of Taylorella equigenitalis, the causative agent of contagious equine metritis, to invade and replicate in equine derm cells was studied. The kinetics of invasion and replication were determined for four T. equigenitalis strains. On the basis of these experiments, a simpler assay in which the invasive as well as the replicative properties of a particular strain could be determined was developed. This assay was used to characterize 32 strains, which had previously been typed by field inversion gel electrophoresis of genomic restriction fragments. The invasiveness of T. equigenitalis...
Thomas PG, Ball BA.To facilitate the study of interactions between equine spermatozoa and homologous oviduct epithelial cells, we developed an assay to count labelled spermatozoa bound to oviduct epithelial cell (OEC) monolayers and used the assay to compare the binding ability of spermatozoa from different stallions. Washed spermatozoa from three stallions were incubated with the fluorochrome Hoechst 33342 (5 micrograms/ml) for 1 min. Spermatozoa were then layered over confluent monolayers of oviduct epithelial cells in 2 cm2 culture wells. Coculture treatments comprised five concentrations of spermatozoa (10(5...
Tangkawattana P, Karkoura A, Muto M, Yamano S, Taniyama H, Yamaguchi M.Numerous rod bodies were found in a heart sample from a 33-year-old pony by a conventional electron-microscopic technique. The rod bodies were concentrated in localized areas of both atria and ventricles, without a specific pattern of distribution. The rods appear to have a typical crystalline-like structure which presumably contains actin backbone filaments and alpha-actinin as major protein constituents. Diminution, fragmentation, and disorganization of the myofibrils, random expansion of electron-dense materials, especially at the fasciae adherens of the intercalated disc, an increase of in...
Stegelmeier BL, Gardner DR, James LF, Molyneux RJ.Houndstongue (Cynoglossum officinale), a noxious weed that contains pyrrolizidine alkaloids (PAs), infests pastures and fields in the western United States and Europe. The purpose of this study was to develop techniques to better diagnose PA poisoning and describe the progression of gross and microscopic lesions caused by houndstongue intoxication. Six horses were gavaged daily with a suspension of houndstongue containing 5 or 15 mg/kg total PA for 14 days. Two horses were treated similarly with ground alfalfa as controls. Liver biopsy samples and serum biochemical and hematologic values were ...
Bigot G, Bouzidi A, Rumelhart C, Martin-Rosset W.Two specimens (70.0 x 4.5 x 1.8 mm) (proximal and distal) of cortical bone were taken from each of the cranial, caudal, lateral and medial quadrants at mid-diaphysis of the third metacarpus and metatarsus of French saddle horses (12 males and seven females) aged from 1 day to 4 years. The mechanical properties (bending strength, Young's modulus, yield stress and ultimate specific deflection) were determined by a 4-point bending test, loading at a rate of 166 x 10(-6) ms-1. During growth, the mechanical properties of the cortical bone were not significantly different (p > 0.05) between metacarp...
Miller MA, Honstead JP, Lovell RA.The fumonisins are a recently discovered class of mycotoxins produced primarily by Fusarium (F.) moniliforme and F. proliferatum. Fumonisins present in mycotoxin-contaminated feed have been identified as the causative agent of equine leukoencephalomalacia and porcine pulmonary edema. To prevent these diseases, FDA has utilized informal guidance levels for fumonisins in feed and initiated a surveillance program for fumonisins in feed corn and corn by-products during FY 93 and 94. Natural contaminants present in animal feed can enter the human food supply as residues present in animal tissues an...
Miserez R, Frey J, Krawinkler M, Nicolet J.A polymerase chain reaction (PCR) for identification of Taylorella equigenitalis was developed. The oligonucleotide primers are based on the DNA sequence of the rrs gene of T. equigenitalis, encoding for the 16S ribosomal RNA. Analysis of 21 strains of T. equigenitalis from England, USA and Switzerland showed an amplification product of 410 bp with identical Sau3A restriction profile. The sensitivity of the PCR-Assay was estimated to detect 50 to 500 bacteria of T. equigenitalis in a mixture with frequently found contaminants. Further analysis of culture from 60 genital swabs, taken in the cou...
Huhtinen M, Reilas T, Katila T.The pregnancy rate is lower in mares inseminated at the first post-partum (p.p.) oestrus (40-50%) compared with pregnancy rates in subsequent oestrous cycles (55-65%). The causes of the lowered pregnancy rate are not fully understood. The aim of the present study was to examine if embryonic defects could be one of the reasons for lowered pregnancy rate. A total of 23 p.p. and 14 non-lactating control mares were flushed 7 days after detection of ovulation. Embryo recovery rate was 48% and 71% in p.p. and control mares, respectively (p = 0.16). Embryos were photographed, measured, graded and sta...
Huhtinen M, Reilas T, Katila T.The pregnancy rate is lower in mares inseminated at the first post-partum (p.p.) oestrus (40-50%) compared with pregnancy rates in subsequent oestrous cycles (55-65%). The causes of the lowered pregnancy rate are not fully understood. The aim of the present study was to examine if embryonic defects could be one of the reasons for lowered pregnancy rate. A total of 23 p.p. and 14 non-lactating control mares were flushed 7 days after detection of ovulation. Embryo recovery rate was 48% and 71% in p.p. and control mares, respectively (p = 0.16). Embryos were photographed, measured, graded and sta...
Burkhard MJ, Baxter G, Thrall MA.A precipitate was observed on the blood films of horses (15 of 16) and one cow given a peritoneal infusion of 1 % sodium carboxymethylcellulose (SCMC) solution to prevent abdominal adhesions. The intensity of the precipitate seen 2 to 3 days post-infusion strongly correlated with the administered dose of SCMC (range 0.96 to 11.7 ml/kg). The dose given was inversely correlated with bodyweight and the most prominent precipitates were seen in foals. The precipitate was observed as early as 24 hours and persisted for as long as 9 days after SCMC administration. Fibrinogen was the only hematologica...
Grier SJ, Turner AS, Alvis MR.The use of dual-energy absorptiometry (DXA) to measure bone mineral content (BMC) and bone mineral density (BMD) is widespread in humans and has been adapted to animals because of the need to examine bone and body composition in longitudinal studies. In this review, the indications and techniques for DXA in small-sized animals (rodents, cats, and rabbits) and large-sized animals (dogs, swine, nonhuman primates, sheep, and horses) are discussed. Now that software has been developed for measuring BMD in small laboratory animals, the most frequent use of DXA in animals is in rats. An ultrahigh-re...
Adeyefa CA, Hamblin C, Cullinane AA, McCauley JW.The objective of this work was to examine the incidence of equine influenza viruses in the equine population of an area of tropical Africa where equine influenza virus activity has recently been reported for the first time. A serological survey of sera from horses and donkeys from regions of Nigeria taken from 1990 to 1993 was carried out and the results obtained were com-pared with equine sera from Western Europe (Ireland). The sera were assayed for presence of antibodies by both haemagglutination inhibition (HI) and ELISA using a monoclonal antibody to the prototype H3 equine influenza virus...
Stanley SM, Wee WK, Lim BH, Foo HC.Direct-injection LC-LC hybrid tandem MS methods have been developed for undertaking broad-based screening for acidic drugs in protein-precipitated plasma and neutral doping agents in equine urine. In both analyses, analytes present in the matrix were trapped using a HLB extraction column before being refocused and separated on a Chromolith RP-18e monolithic analytical column using a controlled differential gradient generated by proportional dilution of the first column's eluent with water. Each method has been optimised by the adoption of a mobile phase and gradient that was tailored to enhanc...
Pollaris E, Broeckx BJG, Rajasekharan S, Cauwels R, Vlaminck L. fracture models are frequently used in human dentistry to provide insights in the fracture mechanisms of teeth. Equine cheek teeth fractures are an important dental pathology, but there has been no research performed to examine the fracture resistance . To evaluate the fracture resistance of equine cheek teeth and identify anatomical predictors that might influence fracture resistance in healthy teeth. It was further evaluated if the presence of a fissure caused a decrease in fracture resistance. experimental design. Individual cheek teeth were subjected to a compression load in a univer...
Vivrette S.The endocrinology of late gestation and parturition in the mare has been described, but unlike other domestic animal species, the factors that initiate parturition in the mare have not been elucidated. In contrast to ruminant species, maternal estrogen and progesterone concentrations do not change markedly, and a well-defined fetal cortisol surge is not observed just prior to parturition in the mare. Parturition is associated with large increases in prostaglandin and oxytocin concentrations, which induce uterine contractions and delivery of the foal. There are many methods of inducing parturit...
Gabriel CR, Marta P.A two-month-old, Spanish breed, foal was referred with right hind limb lameness of two weeks duration. Clinical examinations confirmed a complex combination of lesions within the lateral femorotibial joint, including a subchondral bone cyst in the lateral femoral condyle, a severe popliteal tendonitis, and a delayed cartilage detachment of the lateral femoral condyle. Because of the complex association of these lesions, poor prognosis for an athletic career was given to the owner. Four years later, the filly is pasture sound. Lesions of the popliteal tendon in the horse are uncommon. The popli...
Zhao CJ, Qin YH, Lee XH, Wu Ch.An alleged male foal of a female mule, whose sire and grandparents were unknown, was identified for its pedigree. Parentage testing was conducted by comparing polymorphism of 12 microsatellite DNA sites and mitochondrial D-loop sequences of the male foal and the female mule. Both the sequence analysis of species-specific DNA fragments and a cytogenetic analysis were performed to identify the species of the foal and its parents. The results showed that the alleged female mule is actually a hinny, and the male foal, which possesses 62 chromosomes, qualifies as an offspring of the female hinny an...
Becht JL, Page EH, Morter RL, Boon GD, Thacker HL.A series of modified (field) tests were compared to a crossmatch between mare and foal for their reliability in predicting neonatal isoerythrolysis (NI) in eight foals born to experimentally alloimmunized mares. In the field tests, mare's serum, plasma and colostrum were combined with foal erythrocytes washed by a modified procedure to determine which combination was the best predictor of impending NI. A consistent grading system for agglutination and hemolysis was employed. The field tests using mare's plasma demonstrated less agglutination and hemolysis than tests where serum was employed. I...
Rankins EM, Salem K, Manso Filho HC, Malinowski K, McKeever KH.Clenbuterol (β agonist) is a commonly administered bronchodilator in race and performance horses. While long-term administration can alter exercise performance and muscle properties, little is known about its effects on these parameters following short-term administration. A single dose of clenbuterol (0.80 µg/kg) was expected to alter muscle activity of the extensor carpi radialis, semitendinosus, and longissimus dorsi during submaximal exercise. Eight mature Standardbred horses exercised for 2 minutes at 5 m/s on a high-speed treadmill following clenbuterol dosing (clenbuterol) or no dosin...
Birmingham SSW, Mason RM.Serum amyloid A (SAA) is one of the major acute phase proteins in horses. It serves as a marker for systemic inflammation and infection, as the concentration can increase 100- to even 1000-fold during systemic disease processes. The objective of this study was to evaluate the effect of sedation, oral examination, and odontoplasty on systemic inflammation as measured by SAA in the adult performance horse. This study included 32 clinically healthy adult performance horses. Blood samples were collected immediately prior to sedation, oral examination, and odontoplasty and 48 and 72 hours afterward...
Del Piero F, Wilkins PA, Timoney PJ, Kadushin J, Vogelbacker H, Lee JW, Berkowitz SJ, La Perle KM.A case of fatal nonneurological equine herpesvirus 1 (EHV-1) infection in a yearling filly is described. Gross lesions included extensive pulmonary edema, prominent laryngeal lymphoid follicles, and congestion and edema of the dorsal third ventricle choroid plexus. Histologically, there was vasculitis, hemorrhage, and edema in the lungs and dorsal third ventricle choroid plexus as well as mild intestinal crypt necrosis with occasional intranuclear inclusion bodies. The perivascular and vascular inflammatory infiltrates were comprised mainly of T lymphocytes and macrophages. EHV-1 antigen was i...
Capistrano da Silva E, Gibson DJ, Jeong S, Zimmerman KL, Smith-Fleming KM, Martins BDC.Matrix metalloproteinases (MMPs)-2 and -9 are present in corneal ulcers, and an imbalance between MMPs and tissue inhibitors of metalloproteinases (TIMPs) leads to further corneal degradation. Amniotic membrane homogenate (AMH) has proteolytic properties beneficial for corneal healing, but it is unknown whether AMH possesses TIMPs or effectively inhibits MMP-2 and MMP-9 activity. Objective: To determine if bovine and equine AMH reduce in vitro MMP-2 and MMP-9 activities associated with the presence of TIMPs. Methods: Undiluted and diluted twofold series (0-fold to 16-fold dilutions) of equine ...
Roska S, Morello S, Rajamanickam V, Smith LJ.Effects of lactated Ringer's solution (LRS) and hetastarch 130/0.4 (HES) on colloid osmotic pressure (COP), plasma osmolality (OSM) and total protein (TP) were investigated in 18 inhalational-anaesthetised healthy horses. Horses received 4-6 ml/kg LRS (LRS; n=9) or HES (HES; n=9) from anaesthesia induction through 60 min, after which all were administered LRS. COP, TP and OSM were measured before premedication (baseline), postinduction and 30 (n=18), 60 (n=18), 90 (n=18) and 120 (n=12) minutes. Baseline COP, OSM and TP were not different between groups. TP decreased in both groups at all t...
Naylor JM, Wolker RE, Pharr JW.Twenty students and 16 diplomates listened to 7 recordings made from 7 horses with either aortic (n = 3) or mitral valve (n = 4) regurgitant murmurs. A total of 30 different terms were used to describe the character of these murmurs. However, only 4 terms were used in a repeatable and consistent manner. Most people described the character of a given mitral or aortic valve murmur with 1 or 2 terms. Diplomates drew from a pool of terms that was about half the size of that used by students--8.1 +/- 2.0 terms for diplomats (mean +/- 1 SD) versus 13.1 +/- 1.8 terms for students (P > .001). Only blo...
Coultous R, Gotić J, McCann M, Sutton D, Beck R, Shiels B.The apicomplexan haemoparasite Theileria equi, a causative agent of equine piroplasmosis, is an established pathogen of significant welfare and economic concern within the Croatian equine population. A previous large surveillance study of T. equi has identified two distinct parasite populations, one in the north and one in the south, geographically separated by the Dinaric Alps, which traverse the country. This study aimed to further investigate the genetic diversity within these two populations, focussing on allelic variability of the equi merozoite antigen gene, ema-1. Methods: Following nes...
Steinman A, Sutton GA, Elad D.Rhodococcus equi is an important pathogen in young horses. In recent years it has been increasingly recognized as an opportunistic infectious agent in patients with immune deficiency. The increase in recognized cases may be related to the increased prevalence of AIDS. However, more cases may have been recognized lately due to increased awareness of the pathogenicity of this bacterium. Based on medical reports, there appears to be an association between Rhodococcus equi infections and exposure to animals, horses in particular. During the past year, 2 cases of rhodococcus pneumonia were diagnose...
Ginther OJ, Baucus KL, Bergfelt DR.The ovaries of periparturient pony mares (n=9 to 16 parturitions per month for January to April) were scanned ultrasonically on the day of parturition, while those of postpartum and control mares (n=12) were examined at least twice weekly. Four mares had apparent lactational anovulation (incidence, 7%) that corrected spontaneously (1 mare) or within 14 d after the weaning of foals on August 10 (3 mares). All but 2 of the postpartum ovulations occurred after April 29; that is, parturition did not effectively stimulate ovulation in ponies foaling during the anovulatory season. Mean diameter of t...
Miller LM, Reed SM, Gallina AM, Palmer GH.Two adult horses with progressive neurologic signs were examined clinically and at necropsy. Both horses had signs of progressive ataxia and weakness, clinically diagnosed as spinal cord in origin. Differential diagnoses for cervical spinal ataxia in horses included cervical vertebral malformation, equine degenerative myeloencephalopathy, equine herpes-virus-I myeloencephalopathy, and equine protozoal myeloencephalopathy. Necropsy findings in both horses were similar and consisted of a large hematoma in the fourth ventricle, with upward compression of the cerebellum and downward compression of...
Derksen FJ, Slocombe RF, Gray PR, Robinson NE.The lungs of sensitized horses were exposed to aerosolized ovalbumin. Some horses (n = 4) were given ovalbumin in 1 lung only, whereas in others (n = 7), ovalbumin or vehicle were inoculated in the cranial, ventral, and caudal regions of the caudal lung lobe. Horses were exercised 5 hours after ovalbumin exposure. Immediately before exercise, endoscopy failed to reveal any abnormality. After exercise, endoscopic examination of horses subjected to unilateral ovalbumin exposure revealed extensive blood in airways leading to the exposed lung in all horses. Blood was not observed in the airways le...
Basu R, Chatterjee A.The administration of pregnant mare's serum gonadotropin (PMSG), 30 IU on day 18 of pregnancy, resulted in premature labor in rats. However, this abortifacient efficacy of PMSG was not demonstrable when a simultaneous injection of progesterone, clomiphene, or indomethacin was scheduled, thus suggesting that the action of PMSG is medicated by the estrogen-stimulated release of prostaglandin. The termination of pseudopregnancy in bilaterally hysterectomized rats by PMSG and its reversal by indomethacin revealed that the inhibition of luteal function by PMSG does not require the presence of a ute...
Vercelli C, Tursi M, Miretti S, Giusto G, Gandini M, Re G, Valle E.Laminitis is one of the most devastating diseases in equine medicine, and although several etiopathogenetic mechanisms have been proposed, few clear answers have been identified to date. Several lines of evidence point towards its underlying pathology as being metabolism-related. In the carbonyl stress pathway, sugars are converted to methylglyoxal (MG)-a highly reactive α-oxoaldehyde, mainly derived during glycolysis in eukaryotic cells from the triose phosphates: D-glyceraldehyde-3-phosphate and dihydroxyacetone phosphate. One common hypothesis is that MG could be synthesized during the dig...