Equine health encompasses the study and management of diseases, disorders, and overall well-being of horses. It involves understanding various physiological systems, preventive care, and treatment strategies to maintain optimal health in equine populations. Common areas of focus include nutrition, infectious diseases, orthopedic conditions, and reproductive health. Research in equine health aims to advance knowledge on diagnostic methods, therapeutic interventions, and management practices that improve horse welfare and performance. This page collects peer-reviewed research studies and scholarly articles that explore the diverse aspects of equine health, offering insights into current findings and advancements in the field.
Welsh CE, Lewis TW, Blott SC, Mellor DJ, Stirk AJ, Parkin TD.A retrospective cohort study of distal limb fracture and superficial digital flexor tendon (SDFT) injury in Thoroughbred racehorses was conducted using health records generated by the British Horseracing Authority (BHA) between 2000 and 2010. After excluding records of horses that had both flat and jump racing starts, repeated records were reduced to a single binary record per horse (n = 66,507, 2982 sires), and the heritability of each condition was estimated using residual maximum likelihood (REML) with animal logistic regression models. Similarly, the heritability of each condition was ...
Marycz K, Smieszek A, Grzesiak J, Nicpoń JE.Disorders of the locomotive system, especially those occurring due to degenerative changes of the joints, are serious problems in daily veterinary medical practice. Steroid injections are the main way of treating these disorders. However, this approach brings usually only temporary effects of pain relief, and may cause many side effects. Alternative therapies focus on regeneration of damaged tissue using adult mesenchymal stem cells (MSCs). Since 2002, the great plasticity and immunomodulatory properties of MSCs isolated from adipose tissue (AdMSCs) have been used successfully in the treatment...
Brennan KM, Urschel KL.Dexamethasone is an anti-inflammatory drug commonly used in equine medicine. Insulin sensitivity decreases with prolonged dexamethasone administration, but little information is available about the duration of this side effect after long-term treatment ends. Objective: To determine how long it takes for blood glucose, insulin and markers of insulin sensitivity to return to normal ranges after extended dexamethasone treatment has ceased. Methods: Experimental study. Methods: Eight healthy, mature, mixed-breed horses received 0.04 mg/kg bwt/day oral dexamethasone for 21 days. Blood samples wer...
Philippeau C, Varloud M, Julliand V.To determine prececal starch digestibili-ty and estimate glucose uptake from the digestion of 4 forms of barley in the small intestine, 4 mature cecally fistulated geldings (449 ± 41 kg BW) fed a 62:38 (wt/wt) meadow hay:concentrate diet at 1.7 kg DM/100 kg BW were included in a 4 × 4 Latin square design experiment. During each period, horses received 80% DM of their concentrate as 1 of the 4 forms of a same batch of barley, whole grain, 2.5 mm ground, steam flaked, and pelleted. Hay was offered in 2 equal meals and concentrate in 2 unequal meals. The starch supply in the morning meal amount...
Ley CJ, Ekman S, Hansson K, Björnsdóttir S, Boyde A.Osteochondral lesions in the joints of the distal tarsal region of young Icelandic horses provide a natural model for the early stages of osteoarthritis (OA) in low-motion joints. We describe and characterise mineralised and non-mineralised osteochondral lesions in left distal tarsal region joint specimens from twenty-two 30 ±1 month-old Icelandic horses. Combinations of confocal scanning light microscopy, backscattered electron scanning electron microscopy (including, importantly, iodine staining) and three-dimensional microcomputed tomography were used on specimens obtained with guidance f...
Stoppini R, Tassan S, Barachetti L.An 8-year-old Hanoverian mare was presented for chronic mucopurulent discharge in the left eye, which was responsive to topical antibiotic therapy. Results: The nasolacrimal orifice was absent in the left nasal meatum, and anterograde irrigation of left nasolacrimal duct was not possible. Dacryocystorhinography was performed and revealed about 4-6 cm of distal nasolacrimal duct atresia. Unassigned: A novel technique was attempted with the horse under standing sedation using an urinary catheter and a 980 nm diode laser with a 600 μm diameter flexible bare quartz fiber. A nasolacrimal orifice w...
Sharma R, Livesey MR, Wyllie DJ, Proudfoot C, Whitelaw CB, Hay DC, Donadeu FX.Pluripotent stem cells (PSCs) offer unprecedented biomedical potential not only in relation to humans but also companion animals, particularly the horse. Despite this, attempts to generate bona fide equine embryonic stem cells have been unsuccessful. A very limited number of induced PSC lines have so far been generated from equine fibroblasts but their potential for directed differentiation into clinically relevant tissues has not been explored. In this study, we used retroviral vectors to generate induced pluripotent stem cells (iPSCs) with comparatively high efficiency from equine keratinocy...
Murase H, Endo Y, Tsuchiya T, Kotoyori Y, Shikichi M, Ito K, Sato F, Nambo Y.It has not been common to perform regular ultrasound examination of the fetus in equine practice, due to the increasing volume of the uterus caused by fetal development. The convex three-dimensional transducer is bulb-shaped and is able to observe wide areas. In addition, its operation is simple, making it easy to create appropriate angles for various indices using a transrectal approach. The aim of this study was to measure Thoroughbred fetal growth indices throughout gestation using a convex transducer and to clarify the detectable period of some indices for clinical use. We demonstrated cha...
Nielsen MK, Pfister K, von Samson-Himmelstjerna G.Since the 1960s equine parasite control has relied heavily on frequent anthelmintic treatments often applied with frequent intervals year-round. However, increasing levels of anthelmintic resistance in cyathostomins and Parascaris equorum are now forcing the equine industry to change to a more surveillance-based treatment approach to facilitate a reduction in treatment intensity. The principle of selective therapy has been implemented with success in small ruminant parasite control, and has also found use in horse populations. Typically, egg counts are performed from all individuals in the pop...
Ekiri AB, House AM, Krueger TM, Hernandez JA.To assess awareness, perceived relevance, and acceptance of surveillance and infection control practices at a large animal referral hospital among referring veterinarians and clients who sent horses to the facility for veterinary care. Methods: Survey. Methods: 57 referring veterinarians and 594 clients. Methods: A 15-question survey targeting Salmonella enterica as an important pathogen of interest in horses was sent to clients who sent ≥ 1 horse to the University of Florida Large Animal Hospital for veterinary care during July 1, 2007, through July 1, 2011, and to veterinarians who had ref...
Doran G, Hughes K, Rendle D, Edwards S.Pergolide is used to treat pituitary pars intermedia dysfunction (equine Cushing's Disease), a neurodegenerative condition associated with loss of dopaminergic inhibition of the pituitary in horses. After oral administration, only low concentrations of the drug are achieved in plasma, making drug detection and quantification difficult. While direct analysis of plasma using sensitive MS/MS techniques is possible, dirty plasma samples and mobile phase buffers can cause instrumentation to become rapidly incapacitated. A method using LC with fluorescence detection was developed for pergolide analy...
Lyle SK.Placentitis is reported to be the cause of 9.8-33.5% of abortions, stillbirths and perinatal losses in horses. Bacterial infections are responsible for 53% of placentitis cases with Streptococcus equi ssp. zooepidemicus being isolated in 28% of these cases. Clinically, mares may have a vaginal discharge, show udder development, lactate prenatally and deliver a premature or dead foal. Major aspects of the pathogenesis of infectious preterm delivery that may require more effective therapeutic targeting are myometrial contraction, immunological aspects of preterm delivery, and the effects of proi...
Grevemeyer B, Bogdanovic L, Canton S, St Jean G, Cercone M, Ducharme NG, Brown BN.Airway obstruction is a common cause of poor performance in horses. Structural abnormalities (insufficient length, rigidity) can be a cause for the obstruction. Currently, there are a few effective clinical options for reconstruction of the equine larynx. A regenerative medicine approach to reconstruction may provide the capability to stabilize laryngeal structures and to encourage restoration of site-appropriate, functional, and host-derived tissue. The purpose of this study was the histopathological evaluation of (1) decellularization of equine (horse) laryngeal cartilages (epiglottis and ar...
Le Moyec L, Robert C, Triba MN, Billat VL, Mata X, Schibler L, Barrey E.During long distance endurance races, horses undergo high physiological and metabolic stresses. The adaptation processes involve the modulation of the energetic pathways in order to meet the energy demand. The aims were to evaluate the effects of long endurance exercise on the plasma metabolomic profiles and to investigate the relationships with the individual horse performances. The metabolomic profiles of the horses were analyzed using the non-dedicated methodology, NMR spectroscopy and statistical multivariate analysis. The advantage of this method is to investigate several metabolomic path...
Gulati BR, Kumar R, Mohanty N, Kumar P, Somasundaram RK, Yadav PS.Tendon injuries are common in race horses, and mesenchymal stem cells (MSCs) isolated from adult and foetal tissue have been used for tendon regeneration. In the present study, we evaluated equine amniotic fluid (AF) as a source of MSCs and standardised methodology and markers for their in vitro tenogenic differentiation. Plastic-adherent colonies were isolated from 12 of 20 AF samples by day 6 after seeding and 70-80% cell confluency was reached by day 17. These cells expressed mesenchymal surface markers [cluster of differentiation (CD)73, CD90 and CD105] by reverse transcription (RT)-polyme...
Du J, Wang X, Ma J, Wang J, Qin Y, Zhu C, Liu F, Shao Y, Zhou J, Qiao W, Liu X.The equine infectious anemia virus (EIAV) is a lentivirus of the Retrovirus family, which causes persistent infection in horses often characterized by recurrent episodes of high fever. It has a similar morphology and life cycle to the human immunodeficiency virus (HIV). Its transmembrane glycoprotein, gp45 (analogous to gp41 in HIV), mediates membrane fusion during the infection. However, the post-fusion conformation of EIAV gp45 has not yet been determined. EIAV is the first member of the lentiviruses for which an effective vaccine has been successfully developed. The attenuated vaccine strai...
Williams S, Horner J, Orton E, Green M, McMullen S, Mobasheri A, Freeman SL.A change in management from pasture to stabling is a risk factor for equine colic. Objective: To investigate the effect of a management change from pasture with no controlled exercise to stabling with light exercise on aspects of gastrointestinal function related to large colon impaction. The hypothesis was that drinking water intake, faecal output, faecal water content and large intestinal motility would be altered by a transition from a pastured to a stabled regime. Methods: Within-subject management intervention trial involving changes in feeding and exercise using noninvasive techniques. M...
Cadby JA, Buehler E, Godbout C, van Weeren PR, Snedeker JG.The role of intrinsic and extrinsic healing in injured tendons is still debated. In this study, we characterized cell plasticity, proliferative capacity, and migration characteristics as proxy measures of healing potential in cells derived from the peritenon (extrinsic healing) and compared these to cells from the tendon core (intrinsic healing). Both cell populations were extracted from horse superficial digital flexor tendon and characterized for tenogenic and matrix remodeling markers as well as for rates of migration and replication. Furthermore, colony-forming unit assays, multipotency as...
Giles SL, Rands SA, Nicol CJ, Harris PA.Reasons for performing study. The prevalence of obesity in companion animals, including horses and ponies has risen drastically in recent years and risk factors have been little investigated. Horses are unique amongst companion animals in that many are outdoor-living and forage independently on pasture; they also have a dual utility and companionship role. The body condition of wild and free-living equines is known to vary seasonally, yet previous estimates of the prevalence of obesity and associated risk factors in domestic animals do not consider this. Most previous studies were conducted du...
Desjardin C, Chat S, Gilles M, Legendre R, Riviere J, Mata X, Balliau T, Esquerré D, Cribiu EP, Betch JM, Schibler L.Osteochondrosis (OC) is a developmental bone disorder affecting several mammalian species including the horse. Equine OC is described as a focal disruption of endochondral ossification, leading to osteochondral lesions (osteochondritis dissecans, OCD) that may release free bodies within the joint. OCD lesions trigger joint swelling, stiffness and lameness and affects about 30% of the equine population. OCD is considered as multifactorial but its physiopathology is still poorly understood and genes involved in genetic predisposition are still unknown. Our study compared two healthy and two OC-a...
Iqbal K, Chitwood JL, Meyers-Brown GA, Roser JF, Ross PJ.Formation of the inner cell mass (ICM) and trophectoderm (TE) marks the first differentiation event in mammalian development. These two cell types have completely divergent fates for the remainder of the developmental process. The molecular mechanisms that regulate ICM and TE formation are poorly characterized in horses. The objective of this study was to establish the transcriptome profiles of ICM and TE cells from horse blastocysts using RNA sequencing (RNA-seq). A total of 12 270 genes were found to be expressed in either lineage. Global analysis of the transcriptome profiles by unsupervi...
Del Rosario-Montejo O, Molina-Rueda F, Muñoz-Lasa S, Alguacil-Diego IM.Equine therapy, an intervention method that has been practiced for decades around the world, is used to treat patients susceptible to psychomotor delays. Objective: We examine development of gross motor function compared to other psychomotor skills in patients undergoing this therapy, and analyse how this improvement affects general health status and quality of life. Methods: The study includes 11 children with delayed psychomotor development (aged 8.82 ± 3.89; 6 boys, 5 girls). The main study variables were gross motor function (GMFM-88) and perceived quality of life (Pediatric Quality of ...
Allombert J, Vianney A, Laugier C, Petry S, Hébert L.Taylorella equigenitalis is the causative agent of contagious equine metritis, a sexually-transmitted infection of Equidae characterised in infected mares by abundant mucopurulent vaginal discharge and a variable degree of vaginitis, cervicitis or endometritis, usually resulting in temporary infertility. The second species of the Taylorella genus, Taylorella asinigenitalis, is considered non-pathogenic, although mares experimentally infected with this bacterium can develop clinical signs of endometritis. To date, little is understood about the basic molecular virulence and persistence mechanis...
Brinkschulte M, Bienert-Zeit A, Lüpke M, Hellige M, Ohnesorge B, Staszyk C.Sinusitis is a common disease in the horse. In human medicine it is described, that obstruction of the sinonasal communication plays a major role in the development of sinusitis. To get spatial sense of the equine specific communication ways between the nasal cavity and the paranasal sinuses, heads of 19 horses, aged 2 to 26 years, were analyzed using three-dimensional (3D) reformatted renderings of CT-datasets. Three-dimensional models were generated following manual and semi-automated segmentation. Before segmentation, the two-dimensional (2D) CT-images were verified against corresponding fr...
Dalla Costa E, Minero M, Lebelt D, Stucke D, Canali E, Leach MC.The assessment of pain is critical for the welfare of horses, in particular when pain is induced by common management procedures such as castration. Existing pain assessment methods have several limitations, which reduce the applicability in everyday life. Assessment of facial expression changes, as a novel means of pain scoring, may offer numerous advantages and overcome some of these limitations. The objective of this study was to develop and validate a standardised pain scale based on facial expressions in horses (Horse Grimace Scale [HGS]). Results: Forty stallions were assigned to one of ...
van Balen J, Mowery J, Piraino-Sandoval M, Nava-Hoet RC, Kohn C, Hoet AE.The role that environmental contamination might play as a reservoir and a possible source of Methicillin-resistant Staphylococcus aureus (MRSA) for patients and personnel at equine veterinary hospitals remains undefined, as the environment has only been monitored during outbreaks or for short periods. Therefore, the objectives of this study were to determine the monthly presence, distribution, and characteristics of environmental MRSA at an equine hospital, and to establish patterns of contamination over time using molecular epidemiological analyses. For this purpose, a yearlong active MRSA su...
De Keyser K, Janssens S, Peeters LM, Foqué N, Gasthuys F, Oosterlinck M, Buys N.Genetic parameters for chronic progressive lymphedema (CPL)-associated traits in Belgian Draught Horses were estimated, using a multitrait animal model. Clinical scores of CPL in the four limbs/horse (CPLclin ), skinfold thickness and hair samples (hair diameter) were studied. Due to CPLclin uncertainty in younger horses (progressive CPL character), a restricted data set (D_3+) was formed, excluding records from horses under 3 years from the complete data set (D_full). Age, gender, coat colour and limb hair pigmentation were included as fixed, permanent environment and date of recording as ra...
Martinson KL, Coleman RC, Rendahl AK, Fang Z, McCue ME.Excessive BW has become a major health issue in the equine (Equus caballus) industry. The objectives were to determine if the addition of neck circumference and height improved existing BW estimation equations, to develop an equation for estimation of ideal BW, and to develop a method for assessing the likelihood of being overweight in adult equids. Six hundred and twenty-nine adult horses and ponies who met the following criteria were measured and weighed at 2 horse shows in September 2011 in Minnesota: age ≥ 3 yr, height ≥ 112 cm, and nonpregnant. Personnel assessed BCS on a scale of 1 t...
Miyaji M, Ueda K, Hata H, Kondo S.Eight Thoroughbred horses were used to examine the effects of grass hay intake on the fiber digestion and the retention time of digesta in the total gastrointestinal tract and the hindgut segments. The horses were randomly assigned to 2 groups and offered 2.0 (high intake [HI]) or 1.3 kg DM/(100 kg BW • d; low intake [LI]) of timothy hay in equal amounts every 3 h for 17 d. The digestibility and total tract mean retention time of digesta (tMRT) in the total gastrointestinal tract were measured from d 11 to d 15. To measure the mean retention time of digesta in each hindgut segment (sMRT), th...
McConaghy FF, Green LA, Colgan S, Morris LH.To investigate the efficacy and safety of the long-acting altrenogest injection (NV Readyserve® injection) for horses. Methods: A single-dose pharmacokinetic (PK) study was conducted. The in vivo efficacy study was a blinded, repeated measures design evaluating behaviour scores. The safety study was a non-blinded, controlled, parallel-group, randomised-block design as per the VICH protocol. Methods: In the PK study, serial blood samples were obtained for analysis of plasma altrenogest for 150 h following the injection and a non-compartmental PK analysis was performed. For the efficacy study, ...
Fischer AT.A technique for laparoscopically assisted resection of umbilical structures in foals was developed. Eleven foals ranging from 8 to 42 days old underwent this procedure. Results of bacteriologic culture of umbilical structures were positive in 7 foals. Mean duration of anesthesia was 99 minutes, of which the initial 20 to 25 minutes were typically devoted to positioning and preparation of the foal for surgery. Major complications did not develop in any foal. Minor complications, such as slippage of the endoscopic ligating clip or laceration of the bladder during dissection, were dealt with succ...
Valdés-Martínez A.Computed tomographic arthrography is an imaging technique used for the evaluation of the internal structures of a joint, especially the soft tissues and subchondral bone defects that may communicate with the joint space. Clinical indications, technical aspects, principles of image interpretation, and advantages and disadvantages of this imaging technique for the evaluation of the equine stifle joint are discussed in this article.
Frank BL, Doddman CD, Stokes JE, Carnevale EM.In this retrospective study the morphological characteristics of oocytes and cleavage stage embryos were associated with pregnancy results from clinical intracytoplasmic sperm injection (ICSI) in mares. Oocytes were collected from preovulatory follicles, and images (×200; n=401) were captured for measurements of ooplasm, the perivitelline space and zona pellucida. After ICSI and before transfer into recipients' oviducts, cleavage stage embryos were imaged (n=178). Oocyte donor ages (3-13, 14-19, 20-23, 24-27 years) were compared, as were mares aged 3-13 years without versus with recent histor...
Research in microbiologyFebruary 11, 2003
Volume 154, Issue 1 29-35 doi: 10.1016/s0923-2508(02)00003-7
Silva TA, Rodrigues PH, Ribeiro RN, Noronha FS, Farias Lde M, Carvalho MA.The influence of growth medium, hemin and menadione, blood source and atmosphere of incubation on the expression of hemolytic activity of 25 strains of Prevotella intermedia and Prevotella nigrescens was evaluated. The best hemolytic activity was observed for samples of both species growing in brain heart infusion agar and incubated in Brewer-like anaerobic jars for 48 h. Hemolysis was less intense and occurred later in the presence of hemin and menadione in solid media. beta-Hemolysis was detected for medium supplemented with horse or human blood and alpha-hemolysis was observed when sheep bl...
Schulz AK, Kersten S, Dänicke S, Coenen M, Vervuert I.The present study examined the short-term effects of deoxynivalenol (DON), administered at two different concentrations via a feed preparation using naturally contaminated wheat, on feed intake, liver and kidney metabolism and immunomodulatory properties in horses. Twelve geldings were randomly assigned to one of three dietary treatments for 21 days. DON was provided via naturally contaminated wheat (14.6 ± 6.5 mg DON/kg dry matter). The daily feed intake was adjusted to 4 kg of wheat and 1.7 kg of silage per 100 kg of body weight (BW). Horses were fed one of the following diets: control whea...
Morel MC, Newcombe JR, Hayward K.The importance of elucidating factors affecting reproductive performance and efficiency is of paramount concern to the equine industry. Oocyte viability is known to be one of the determinants of reproductive success and evidence suggests that it may be linked to follicle size. The aims of this study were, therefore, to ascertain: i) the average diameter and range of pre-ovulatory follicles in Thoroughbred mares; ii) whether this is affected by either mare age, time within the breeding season, or the presence of multiple pre-ovulatory follicles (MO). One thousand, four hundred and ninety two Th...
Kelley DE, Gibbons JR, Smith R, Vernon KL, Pratt-Phillip SE, Mortensen CJ.The objectives were to evaluate the effects of exercise on ovarian folliculogenesis and related hormones in mares. Mares (n = 11) were randomly assigned into a control (non-exercised) or treatment (exercised) group. Treatment mares (n = 5) were moderately exercised for 30 min, 6 d/wk. All mares underwent daily transrectal ultrasonographic examinations and ovarian follicles > 6 mm were measured. Blood samples were collected during the first (Cycle 1) and last (Cycle 4) cycle, and serum concentrations of cortisol, LH, and FSH were determined. Mean cortisol concentrations were elevated (P <...
Santos MP, Gutierrez-Nibeyro SD, McKnight AL, Singh K.With the recent introduction of a 0.25T rotating MRI system, clinical evaluation of the equine stifle joint is now possible in the average equine athlete. A recent publication described common abnormalities of horses with stifle lameness detected with a low-field MRI system; however, postmortem corroboration of the lesions detected was not possible. Therefore, our objective was to compare postmortem findings with low-field MRI findings in equine cadaver stifle joints. Ten fresh cadaver stifle joints from horses without clinical signs of stifle disease were evaluated using low-field MRI, gross ...
Moura I, Radhouani H, Torres C, Poeta P, Igrejas G.Lusitano horses were investigated in order to detect the presence of vancomycin-resistant enterococci. vanA isolates showed high level vancomycin (Minimum inhibitory concentration; MIC > or = 128 mg/l) and teicoplanin resistance (MIC 64 mg/l), as well as resistance to ciprofloxacin, erythromycin and tetracycline. The tet(L) and erm(B) genes, associated with tetracycline and erythromycin resistance, respectively, were found in all vanA isolates. The intestinal tract of Lusitano horses can be a potential reservoir for vanA-containing enterococci.
Monahan CM, Taylor HW, Chapman MR, Klei TR.Protection from Strongylus vulgaris infection through immunization with radiation-attenuated third-stage larvae (L3) or crude soluble homogenates from larval or adult stages was examined. Yearling ponies raised parasite-free were divided into 3 immunization groups: radiation-attenuated L3; soluble adult somatic extracts; larval somatic extracts with excretory/secretory products (E/S) from in vitro culture; and 1 medium control group. Ponies were immunized twice; attenuated larvae were administered orally and somatic extracts or controls injected intramuscularly with adjuvant. Approximately 6 w...
Scherrer NM, Lassaline M, Engiles J.To determine the characteristics of and prognosis for ocular and periocular hemangiosarcoma in horses. Methods: Six horses treated for ocular or periocular hemangiosarcoma. Methods: A retrospective review of medical records from 2007 to 2015 was performed to identify horses with a histologic diagnosis of ocular or periocular hemangiosarcoma. Signalment (age, sex, breed), duration of clinical signs, prior treatment, tumor size and location, medical and surgical treatment including postoperative chemotherapy, follow-up time, and outcome were obtained from medical records. Histopathology was revi...
Lanovaz JL, Khumsap S, Clayton HM, Stick JA, Brown J.The tarsal joint is a common site of injury for many sport horses. Understanding the biomechanics of this complex joint begins with developing a clear picture of the kinematics during normal locomotion. This study describes the 3D kinematics of the tarsal joint by measuring the motion of the tibia and third metatarsus in 4 sound Quarter Horses with targets attached directly to the bones via steel pins. The objective was to determine if the tarsus had significant motion outside the tarsocrural joint. Two Steinmann pins were inserted into the lateral side of the right hindlimb and marker triads ...
Lavoie JP, Couture L, Higgins R, Laverty S.Bacterial isolations were reviewed from equine trachea, guttural pouch, uterus, wounds, abscesses, blood, synovial fluid, and abdominal fluid submitted to the Clinical Bacteriology Laboratory of the School of Veterinary Medicine at the University of Montreal for aerobic bacterial culture from 1986 to 1988. Of the 733 samples submitted, 324 (44%) were positive for bacterial growth, and 233 antimicrobial sensitivity tests were performed. Seventy-six percent of all positive samples yielded one bacterial species and two were isolated from 22% of positive samples. Streptococcus zooepidemicus, Esche...
Chauhan M, Gupta AK, Dhillon S.The genetic relationships of three Indian horse breeds-Marwari, Spiti, and Kathiawari were studied by genotyping 96 individuals with 20 polymorphic microsatellite markers. A total of 157 alleles were detected across 20 polymorphic loci. The Marwari population showed the highest allelic diversity (A = 5.7 and Ar = 5.14), followed by Spiti (A = 4.9 and Ar = 4.74) and Kathiawari (A = 4.1 and Ar = 3.82). The gene diversity was highest in the Spiti population (He = 0.67), followed by Marwari (He = 0.66) and Kathiawari (He = 0.59). Within population inbreeding estimates (f) in Marwari, Spiti and Kat...
Hendrickson EHS, Lykkjen S, Dolvik NI, Olstad K.Young Standardbred horses frequently develop fragments in joints. Some fragments represent osteochondrosis; others are considered developmental, but it is uncertain whether they result from preceding osteochondrosis. Osteochondrosis occurs as a consequence of failure of the cartilage canal blood supply and ischaemic chondronecrosis. In heritably predisposed foals, failure was associated with incorporation of vessels into bone. However, bacterial vascular failure was also recently documented in foals suffering spontaneous infections, proving that bacteria can cause osteochondral lesions in foal...
Stuhtmann G, Oldenhof H, Peters P, Klewitz J, Martinsson G, Sieme H.Density gradient centrifugation can be used for selection of sperm of superior quality and removal of seminal plasma for use in artificial insemination. In this study, the use of two-layer iodixanol density gradient centrifugation was evaluated for processing of stallion semen. The protocol includes centrifugation through a 16% iodixanol top layer of 1.090 g mL(-1) and collection of motile and intact sperm on a 30% iodixanol bottom layer of 1.165 g mL(-1). Sperm recovery and effects on sperm quality were determined during cold storage as well as after cryopreservation and compared with ordinar...
Kvaternick V, Malinski T, Wortmann J, Fischer J.A sensitive reversed-phase HPLC-UV method was developed for the determination of firocoxib, a novel and highly selective COX-2 inhibitor, in plasma. A 1.0 mL dog or horse plasma sample is mixed with water and passed through a hydrophobic-lipophilic copolymer solid-phase extraction column to isolate firocoxib. Quantitation is based on an external standard curve. The method has a validated limit of quantitation of 25 ng/mL and a limit of detection of 10 ng/mL. The validated upper limit of quantitation was 2500 ng/mL for horses and 10,000 ng/mL for dogs. The average recoveries ranged from 88-93% ...
Kamerling SG, DeQuick DJ, Weckman TJ, Tobin T.The dose-related effects of intravenously administered fentanyl (0.010, 0.005, 0.0025 mg/kg) and saline were studied in mature performance horses using a rigorous experimental protocol. Fentanyl produced a dose-related prolongation of the skin twitch reflex latency but did not increase the hoof withdrawal reflex latency. Dose related increases in stepping frequency, cardiac and respiratory rats were observed following fentanyl, while changes in rectal temperature and pupil area were not. These data indicate that fentanyl, a prototypic mu-agonist, produces a syndrome characterized by analgesia,...
Rushton JO, Kolodziejek J, Nell B, Nowotny N.The aim of this study was to assess the extent of asinine herpesvirus (AsHV) type 5 infection in 'closed' populations of clinically normal Lipizzaner horses. Peripheral blood mononuclear cells plus nasal and conjunctival swabs were obtained on four occasions over an 18 month period from 266 animals as part of a health surveillance programme. Sequence analysis of samples that were positive by nested consensus herpesvirus PCR but negative using quantified equid herpesvirus (EHV) type 2 and 5 PCR, revealed a total of 51 samples from 39 horses positive for AsHV-5. No statistically significant asso...
Colitz CM, Latimer FG, Cheng H, Chan KK, Reed SM, Pennick GJ.To determine the pharmacokinetics of voriconazole following IV and PO administration and assess the distribution of voriconazole into body fluids following repeated PO administration in horses. Methods: 6 clinically normal adult horses. Methods: All horses received voriconazole (10 mg/kg) IV and PO (2-week interval between treatments). Plasma voriconazole concentrations were determined prior to and at intervals following administration. Subsequently, voriconazole was administered PO (3 mg/kg) twice daily for 10 days to all horses; plasma, synovial fluid, CSF, urine, and preocular tear film con...
Desanti-Consoli H, Bouillon J, Chapuis RJJ.Vaccination against infectious diseases is a cornerstone of veterinary medicine in the prevention of disease transmission, illness severity, and often death in animals. In North American equine medicine, equine vaccines protecting against tetanus, rabies, Eastern and Western equine encephalomyelitis, and West Nile are core vaccines as these have been classified as having a heightened risk of mortality, infectiousness, and endemic status. Some guidelines differ from the label of vaccines, to improve the protection of patients or to decrease the unnecessary administration to reduce potential sid...
McLean AN.Overshadowing is a process known in behavioral science that occurs when two stimuli of different strengths are applied simultaneously to a nonhuman animal. Typically, the stronger stimulus overshadows the weaker one, resulting in attenuation of the weaker stimulus. This phenomenon explains ways in which the decreased responsiveness and consequent conflict behaviors (and possibly learned helplessness and wastage) in some performance horses can result from the application of two concurrent aversive stimuli. Despite some adverse consequences in the context of ridden horses, overshadowing can have...
Gomez DE, Biermann NM, Sanchez LC.The quantitative effect of strong electrolytes, unmeasured strong anions (UAs), pCO2, and plasma protein concentrations in determining plasma pH can be demonstrated using the physicochemical approach. Plasma anion gap (AG) and strong ion gap (SIG) are used to assess UAs in different species. Objective: Strong ions are a major factor influencing changes in plasma pH of hospitalized foals. AG and SIG accurately predict severe hyper-L-lactatemia ([L-lac(-)] > 7 mmol/L). Methods: Seven hundred and ninety three hospitalized foals < 7 days old. Methods: Retrospective study. The relationship be...
Xiong Q, Bekebrede H, Sharma P, Arroyo LG, Baird JD, Rikihisa Y.Neorickettsia (formerly Ehrlichia) risticii is an obligatory intracellular bacterium of digenetic trematodes. When a horse accidentally ingests aquatic insects containing encysted trematodes infected with N. risticii, the bacterium is transmitted from trematodes to horse cells and causes an acute and often fatal disease called Potomac horse fever (PHF). Since the discovery of N. risticii in the United States in 1984, using immunofluorescence and PCR assays, PHF has been increasingly recognized throughout North America and South America. However, so far, there exist only a few stable N. ristici...
Hampson BA, Connelley AD, de Laat MA, Mills PC, Pollitt CC.To determine solar load-bearing structures in the feet of feral horses and investigate morphological characteristics of the sole in feral horses and domestic Thoroughbreds. Methods: Forelimbs from cadavers of 70 feral horses and 20 domestic Thoroughbreds in Australia. Methods: Left forefeet were obtained from 3 feral horse populations from habitats of soft substrate (SS [n = 10 horses]), hard substrate (HS [10]), and a combination of SS and HS (10) and loaded in vitro. Pressure distribution was measured with a pressure plate. Sole depth was measured at 12 points across the solar plane in feet ...
