Veterinary research in horses encompasses the study of diseases, health management, and medical treatments specific to equine species. This field investigates various aspects of horse health, including infectious diseases, metabolic disorders, and musculoskeletal conditions. Researchers focus on understanding the pathophysiology of equine ailments, developing diagnostic tools, and evaluating therapeutic interventions. The study of horse health also involves examining preventive measures such as vaccination protocols and nutritional management to promote overall well-being. This page collects peer-reviewed research studies and scholarly articles that explore the diverse areas of veterinary science related to horses, providing insights into disease mechanisms, treatment strategies, and advancements in equine healthcare.
Ray CS, Baxter GM, McILWRAITH CW, Trotter GW, Powers BE, Park RD, Steyn PF.The objective of this study was to determine if damage to the articular cartilage alone or articular cartilage plus subchondral bone of the distal medial femoral condyle of young, exercised horses resulted in the formation of subchondral cystic lesions. Twelve Quarter Horses (age 1-2 years), free of clinical and radiographic signs of osteochondrosis and lameness were used. In 6 horses (Group 1), a 15 times 1 mm linear full thickness defect in the articular cartilage was made arthroscopically on the weightbearing surface of the distal aspect of the medial femoral condyle. In the other 6 horses ...
BonenClark GD, MacKay RJ, Ward RE, Sheerin B.To evaluate the humoral response of horses to vaccination, using a murine monoclonal anti-idiotypic antibody (A4) that shares an epitope with lipid A. Methods: Serum concentrations of antilipid A antibody and 1C9 (epitope on murine monoclonal antilipid A antibody) were measured serially during the period of vaccination with A4. Methods: 6 clinically normal adult ponies. Methods: Ponies were inoculated IM 3 times at monthly intervals with A4. Two weeks after each inoculation, serum was obtained and was assayed by ELISA for antilipid A and 1C9 concentrations. Additional vaccinations were given t...
Anderson GS, Belton P, Jahren E, Lange H, Kleider N.Immunotherapy was used to treat horses in British Columbia for Culicoides hypersensitivity. This is a severe, chronic, recurrent allergic disease of horses that results in severe irritation, large lesions, hair loss and secondary infection in the ventral midline, mane, and proximal region of the tail. A crude Culicoides extract was injected subcutaneously, in increasing doses, into 10 horses that were affected severely by the disease. Weekly doses reduced the clinical signs in 9 of the 10 horses in the 1st yr. Eight horses were treated with a maintenance dose during a 2nd yr. After the 2nd yr,...
Kasapi MA, Gosline JM.The mechanical properties of fully hydrated equine hoof wall were examined at various loading rates in compact tension (CT) fracture, tensile and three-point bending dynamic tests to determine possible effects of hoof wall viscoelasticity on fracture toughness and tensile parameters. Four cross-head rates were used in CT tests: 1.7 x 10(-5), 1.7 x 10 (-3), 1.7 x 10(-2) and 2.5ms-1; four strain rates were used in tensile tests: 1.6 x 10(-3), 3.2 x 10(-2), 0.33 and 70s(-1). Speeds for the highest test rates were achieved using a large, custom-built impact pendulum. Bending test frequencies range...
Nolan A, Reid J, Welsh E, Flaherty D, McCormack R, Monteiro AM.The pharmacokinetics of propofol and ketamine administered together by infusion were investigated in four ponies. Blood propofol and plasma ketamine and norketamine concentrations were measured by high performance liquid chromatography. After premedication with detomidine (20 micrograms kg-1) anaesthesia was induced with ketamine (2.2 mg kg-1 intravenously). The trachea was intubated and the ponies were allowed to breathe 100 per cent oxygen. A bolus dose of propofol (0.5 mg kg-1) was then administered intravenously and propofol and ketamine were infused for 60 and 45 minutes, respectively. Th...
Crabill MR, Cohen ND, Martin LJ, Simpson RB, Burney N.Equine synovial fluid aliquots were inoculated with Salmonella enteritidis, Escherichia coli, Actinobacillus equuli, Staphylococcus aureus, and Streptococcus zooepidemicus to obtain approximate concentrations of 1000, 100, 10, and 1 colony forming U/mL. Synovial fluid aliquots were also inoculated with an unquantitated inoculum of Bacteroides fragilis and Clostridium perfringens. Inoculated synovial fluid was incubated in trypticase-soy broth or Columbia broth for approximately 12 hours. Then aliquots were removed for DNA extraction and polymerase chain reaction (PCR) analysis for detection of...
Sellon DC, Levine J, Millikin E, Palmer K, Grindem C, Covington P.The records of 3,952 equine patients presenting to the Veterinary Teaching Hospital at North Carolina State University College of Veterinary Medicine were evaluated to determine risk factors associated with thrombocytopenia. Of 2,346 horses from which a CBC was obtained, 35 (1.49%) were thrombocytopenic (platelet count < 75,000/microL). A reference population of 189 horses with normal platelet counts (75,000 to 300,000/microL) was also studied. Standardbred horses were at increased risk for thrombocytopenia, but age and gender were not identified as significant risk factors. Horses with inf...
Reef VB, Vaala WE, Worth LT, Sertich PL, Spencer PA.Mares with complicated pregnancies (illness, problems at parturition or delivery of an abnormal foal, n = 30) were scanned transabdominally from 298 days gestation to term in order to measure fetal size, evaluate fetal well-being and characterise the intrauterine environment. The results of the last scan obtained prior to parturition were compared to normal data obtained from fetuses of comparable gestational age to develop a biophysical profile specific for the equine fetus. Twelve mares produced a normal foal (positive outcome) and 18 mares delivered 19 abnormal foals (negative outcome). Bot...
Esser AF, Tarnuzzer RW, Tomlinson S, Tatar LD, Stanley KK.Lack of hemolytic activity of horse serum is an inherent property of horse C9. To understand the molecular reasons for this deficiency we have cloned C9 cDNA from a horse liver cDNA library and have sequenced the cDNA yielding the complete coding sequence for horse C9. Purification of C9 from horse plasma and microsequencing established the N-terminus of the mature protein and verified that the correct horse C9 cDNA clone had been isolated. The deduced amino acid sequence corresponds to a mature protein of 526 amino acids that is 77% identical to human C9. It has the same domain structure as h...
Jackson CA, DE Lahunta A, Cummings JF, Divers TJ, Mohammed HO, Valentine BA, Hackett RP.The effectiveness of spinal accessory nerve branch biopsy evaluation as a means to confirm the diagnosis of equine motor neuron disease (EMND) was investigated. Sixteen horses with histories and clinical signs suggestive of EMND and 16 control horses with neither histories nor clinical signs of any neurological disorder, were subjects of the study. Biopsy samples of the ventral branch of the spinal accessory nerve were obtained either surgically, under general anaesthesia or post mortem immediately after euthanasia. Evaluation was done on the spinal cord of all horses to serve as the definitiv...
de Verdier Klingenberg K, Esfandiari J.An immunochromatographic test for the detection of group A rotavirus was evaluated against a reference group A rotavirus ELISA, by using a panel of 161 bovine, porcine and equine faecal samples submitted for routine examination. The sensitivity of the test was 89 per cent and the specificity 99 per cent compared with the ELISA. Its reproducibility was 100 per cent. The simplicity and rapidity of the test procedure make it suitable for use in practice.
Christensen P, Whitfield CH, Parkinson TJ.The ability of the glycosaminoglycan, heparin, and the calcium ionophore, A23187, to induce acrosome reaction in equine spermatozoa was assessed using semen from 3 warmblood stallions of known high fertility. After collection of semen, the spermatozoa were washed and incubated in vitro with heparin or A23187. Incubation periods were 0, 4, 6 or 8 h with 0, 1, 10 or 100 microg/ml heparin or 0, 10, 30 or 60 min with 0, 0.01, 0.1, 1 or 10 microM A23187, respectively. Acrosome reactions were determined by staining the spermatozoa with naphthol yellow S plus erythrosin B, and sperm viability was ass...
Daels PF, Chang GC, Hansen B, Mohammed HO.We have characterized the testosterone secretion pattern during the first 80 d of pregnancy in mares and determined the sources that contribute to circulating testosterone levels during this period. Ten untreated, pregnant mares (Group 1), 10 altrenogest-treated, pregnant mares (Group 2), and 10 altrenogest-treated, pregnant mares in which the CL was eliminated by administration of PGF-2alpha on Day 16 (Group 3) were used in this study. Complete luteolysis occurred following PGF-2alpha administration in all mares in Group 3. Six of the 10 mares in Group 3 did not have an active CL until after ...
Atwill ER, Mohammed HO.To determine whether horses in New York should be vaccinated against equine monocytic ehrlichiosis (EME). Methods: Decision-tree analyses of data from a cross-sectional study and a case-control study. Methods: Horses in New York. Methods: Annual expected monetary loss per horse attributable to EME was calculated for vaccinated and nonvaccinated horses in New York. Because risk of being seropositive was dependent on county in which the horse was located, farm elevation, and use of each horse, decision-tree analyses were stratified by these factors. Results: Annual expected monetary loss per hor...
Neto LM, Andraus MH, Salvadori MC.A method is described for the qualitative and quantitative determination of phenylbutazone and oxyphenbutazone in horse urine and plasma samples viewing antidoping control. A horse was administered intravenously with 3 g of phenylbutazone. For the qualitative determination, a screening by HPLC was performed after acidic extraction of the urine samples and the confirmation process was realized by GC-MS. Using the proposed method it was possible to detect phenylbutazone and oxyphenbutazone in urine for up to 48 and 120 h, respectively. For the quantitation of these drugs the plasma was deprotein...
Pycock JF, Newcombe JR.The effects on pregnancy rate of three different treatments to remove intrauterine fluid were assessed in 1267 mares. The mares were mated and allocated, in strict rotation, to four treatment groups: 1) untreated controls, 2) intrauterine infusion of broad spectrum antibiotics, 3) intravenous injection of oxytocin, 4) intravenous injection of oxytocin followed by intrauterine antibiotics. The pregnancy status of the mares was determined 13 to 15 days and 27 to 30 days after ovulation by transrectal ultrasonography. The pregnancy rate of group 4 (72 per cent) was higher than that of group 2 (64...
Maddison JE.Seventy-seven reports of suspected adverse drug reactions (ADRs) were received by the Adverse Drug Reaction Subcommittee (ADRSc) of the Australian Veterinary Association from April 1993 to December 1994 inclusive. The number of reports received/number of animals involved per species were: dogs (32/44), cats (18/31), horses (17/48), and cattle (10/21). Of these, 49 (64%) were classified as definite ADRs and 9 (12%) as probable ADRs. In 11 (14%) reports an ADR could not be substantiated or there was insufficient information available to make a decision. Eight reports were not classified because ...
Loredo GA, MacDonald MH, Benton HP.To investigate whether recombinant human bone morphogenetic protein-2 (rhBMP-2) regulates glycosaminoglycan (GAG) synthesis and release from equine articular cartilage explant cultures. Methods: Equine articular cartilage explants were maintained in vitro for 7 days in the presence of 0 (control), 1, 10, or 100 ng of rhBMP-2/ml. Synthesis and release of GAG were assessed as measures of production and degradation of the extracellular matrix, respectively. Methods: 6 horses (age range, 2 to 25 years old) without clinically detectable musculoskeletal abnormalities. Methods: Rate of synthesis of G...
Seidel GE.Principles and procedures for cryopreservation of equine embryos are described. Embryos less than 250 microM in diameter can be cryopreserved successfully if glycerol is used as the cryoprotectant. Cooling is takes place in such a way that most of the water leaves the cells before intracellular ice forms, and glycerol is removed after thawing without undue osmotic swelling of cells. Vitrification procedures also show promise for small embryos. Satisfactory procedures for cryopreserving embryos of more than 250 microM in diameter are not yet available.
Keegan KG, Wilson DA, Kreeger JM, Ellersieck MR, Kuo KC, Li Z.To evaluate the distribution of mepivacaine hydrochloride after distal interphalangeal (DIP) joint injection in horses. Methods: Prospective, uncontrolled study. Methods: 10 adult horses. Methods: 30 minutes before euthanasia, 8 ml of 2% mepivacaine hydrochloride was injected into the dorsal pouch of a forelimb DIP joint. Synovial tissue from the DIP joint and podotrochlear (navicular) bursa and bone tissue from the medullary cavity of the distal sesamoid (navicular) bone were taken from both forelimbs immediately after death. All synovial and bone specimens were analyzed for tissue concentrat...
Graham JK.Methodologies to capacitate bovine spermatozoa, induce the acrosome reaction, and fertilize bovine oocytes in vitro have been established. The capability to do the same with stallion spermatozoa, however, is not available. Several different methods have been used to capacitate stallion spermatozoa with variable results. More basic research needs to be done to establish in vitro conditions necessary to capacitate and induce an acrosome reaction in stallion spermatozoa. Although much progress can be expected in this area, it is unlikely that the general practitioner will use these technologies i...
Smith KC, Mumford JA, Lakhani K.Four Welsh Mountain pony mares at 3 months of gestation and one mare at 5 months were inoculated intranasally with equid herpesvirus-1 (EHV-1: Ab4 isolate) at doses of 10(5) to 10(6.6) TCID50. All five mares became infected, but no cases of paresis or abortion occurred. On days 8, 9, 11, 12 (3-month-pregnant mares) and 13 (5-month-pregnant mare) after infection, a detailed examination of the pregnant uterus was made. Small numbers of vascular lesions with EHV-1 antigen expression in endothelial cells were present in the uteri of the early gestational mares; thrombi were rare and foci of thromb...
Dobrinski I, Suarez SS, Ball BA.Interaction of spermatozoa with oviductal epithelial cells (OEC) in the oviductal isthmus prolongs the life span of spermatozoa. The hypothesis that the interaction of equine spermatozoa with OEC affects their intracellular calcium concentration ([Ca2+]i) was tested in a sperm-OEC coculture model. Changes in [Ca2+]i in spermatozoa loaded with the fluorescent calcium indicator indo-1 acetoxymethylester (AM) were determined for spermatozoa attached to OEC or to Matrigel, as well as for free-swimming spermatozoa incubated without oviductal epithelium. [Ca2+]i was determined before incubation and ...
McCue PM.Development of a superovulation technique that is successful, safe, and commercially available would revolutionize the equine breeding industry. However, the reality is that ovulation rates for mares following existing superovulatory treatment are much lower than for cattle. This dichotomy has been attributed to the relatively limited area available in the ovulation fossa for ovulation to occur, combined with the large size of the equine preovulatory follicle. In addition, the number of ovulations in the mare may be limited physiologically by the size of the follicular cohort that may be rescu...
Engelking LR, Dodman NH, Hartman G, Valdez H, Spivak W.Effects of halothane anesthesia were investigated in ponies prepared surgically with chronic external biliary fistulas (T tubes) to determine the effects on liver function and biliary excretion during 2 hours of anesthesia. Four studies were performed on 2 ponies, 2 to 6 months after surgery with the enterohepatic circulation held intact between studies. Intravenous bile acid infusion was used to maintain steady-state bile flow, bilirubin, and bile acid excretion during each study. Compared with the immediate 2-hour preanesthesia values (base line), halothane caused a 138% increase in bilirubi...
Stadler P, Weinberger T, Deegen E.Twenty adult warm blooded horses (body weight 585 +/- 59 kg) were evaluated with pulsed doppler echocardiography. Locations for the transducer and the sample volume were determined to get typical blood flow tracings of the equine heart. Angle of doppler beam was between 37 degrees and 40 degrees in right heart atrioventricular flow tract and between 44 degrees and 47 degrees in left heart atrioventricular flow tract. Peak blood flow velocity (angle corrected) was 0.71 +/- 0.17 m/s in tricuspid valve and 0.92 +/- 0.22 in mitral valve. In right and left atrioventricular flow tracts in all sample...
Friedman DS, Schoster JV, Pickett JP, Dubielzig RR, Czuprynski C, Knoll JS, Wolfgram LJ.The fungal organism Pseudallescheria boydii was isolated from the cornea of a Quarter Horse with ulcerative keratitis. Despite aggressive hourly medication through a subpalpebral lavage system, with drugs including miconazole and natamycin, the cornea developed a stromal abscess. Orbital exenteration was performed after 3 weeks. The fungal isolate was later determined to be resistant to all 8 antifungal drugs tested. Microscopic examination of the cornea revealed fungal hyphae throughout the corneal stroma and penetrating the Descemet membrane. Pseudallescheria boydii has not been implicated p...
López-Sanromán FJ, Freilich GM, Gomez-Cisneros D, Varela M, Santiago I, Manso-Díaz G.The objective of the present study was to compare, using accelerometry, the gait changes produced after administration of a dose of 0.2 mg/kg of morphine at the walk in healthy horses. Six mature horses were used, and all animals received two different treatments with, at least, two weeks interval in between. Treatments administered consisted of a single dose of 10 ml of saline solution or a total of 0.2 mg/kg of morphine diluted in 10 ml of saline solution. A three-dimensional accelerometric device was used to collect data continuously while horses were walking. The walking test was performed...
Gadaj A, Ventura E, Healy J, Botrè F, Sterk SS, Buckley T, Mooney MH.Selective androgen receptor modulators (SARMs) represent non-steroidal agents commonly abused in human and animal (i.e. equine, canine) sports, with potential for further misuse as growth promoting agents in livestock-based farming. As a direct response to the real and possible implications of illicit application in both sport as well as food production systems, this study incorporated enzymatic hydrolysis (β-glucuronidase/arylsulfatase) into a previously established protocol while maintaining the minimal volume (200 µL) of urine sample required to detect SARMs encompassing various pharmacop...
Ellis KL, Barrett MF, Selberg KT, Frisbie DD.Pathology involving the oblique sesamoidean ligaments (OSLs) is commonly diagnosed during magnetic resonance imaging (MRI) of the equine distal limb. Presence of striations within the ligament and magic angle artefact can result in an incorrect diagnosis of pathological change. No studies have been performed using histopathology, the gold standard, to corroborate their imaging diagnosis. Objective: (a) To determine which MRI characteristics are associated with normal vs abnormal OSLs and (b) to evaluate the ability of MRI to correctly identify abnormal vs normal oblique sesamoidean ligaments u...
Frazer JL, Perkins NR, Pitt D.During the 2007 equine influenza (EI) outbreak, infected horses were quarantined at Morgan Park Recreational Grounds (MPRG) near Warwick, Queensland. Some individuals caring for horses were reported to have made return journeys between MPRG and home properties containing other horses during the time there was active infection at MPRG. Objective: A retrospective cohort study to assess the biosecurity and hygiene measures undertaken and their outcomes. Methods: All individuals recorded as being responsible for caring for one or more horses at MPRG, and who were also recorded on entry and exit lo...
Dirikolu L, Karpiesiuk W, Lehner AF, Tobin T.Toltrazuril sulfone (ponazuril) is a triazine-based antiprotozoal agent with clinical application in the treatment of equine protozoal myeloencephalomyelitis (EPM). In this study, we synthesized and determined the bioavailability of a sodium salt formulation of toltrazuril sulfone that can be used for the treatment and prophylaxis of EPM in horses. Toltrazuril sulfone sodium salt was rapidly absorbed, with a mean peak plasma concentration of 2400 ± 169 (SEM) ng/mL occurring at 8 h after oral-mucosal dosing and was about 56% bioavailable compared with the i.v. administration of toltrazuril sul...
Petrov KK, Dicks LM.The aim of this study was to determine which of the two species, Fusobacterium necrophorum or Dichelobacter nodosus, are associated with hoof thrush in horses. Fourteen hoof samples, collected from eight horses with thrush and 14 samples collected from eight horses with healthy hooves, were examined for the presence of F. necrophorum, Fusobacterium equinum and D. nodosus. Only isolates with phenotypic characteristics representing Fusobacterium could be cultured. Total DNA extracted from the 28 hoof samples was amplified by using DNA primers designed from gene lktA, present in F. necrophorum su...
Dunkel B, Rickards KJ, Page CP, Cunningham FM.Platelet activation occurs in human obstructive airway diseases and in laboratory animal models. However, there is limited evidence that platelets may be involved in equine recurrent airway obstruction (RAO) and other inflammatory diseases. This study investigated whether platelet activation also occurred in RAO. Objective: Platelet function is altered in ponies with active RAO. This alteration can be detected ex vivo by measuring platelet adhesion. Methods: An in vitro platelet adhesion assay measuring acid phosphatase (AcP) activity colorimetrically was adapted for use with equine platelets ...
Bailly-Chouriberry L, Cormant F, Garcia P, Kind A, Popot MA, Bonnaire Y.Cobra venom (Naja kaouthia) contains a toxin called α-cobratoxin (α-Cbtx). This toxin is a natural protein containing 71 amino acids (MW 7821 Da) with a reported analgesic potency greater than morphine. In 2007, in USA, this substance was found in the barns of a thoroughbred trainer and since then till date, the lack of a detection of this molecule has remained a recurring problem for the horseracing industry worldwide. To solve this problem, the first method for the detection of α-cobratoxin in equine plasma has now been developed. Plasma sample (3 mL) was treated with ammonium sulfate at ...
Reid CJ, Thompson L, Donnelly S, Deaton CM, Marlin DJ, Carrington SD, Irwin JA.Recurrent airway obstruction (RAO) is a chronic inflammatory condition in equine lung, which may share a common immunological basis with human asthma, in which dysregulated Th2 responses occur. Mammals express chitinases and chitinase-like proteins, two of which are active enzymes, chitotriosidase and acidic mammalian chitinase (AMCase). Both enzymes are upregulated in a range of inflammatory conditions, including asthma. We investigated the activity of chitinase in bronchoalveolar lavage fluid from horses with and without RAO in response to organic dust challenges. No significant differences ...
Štritof Z, Mitchell C, Turk N, Habuš J, Hađina S, Perharić M, Waller AS.Clinical cases resembling strangles are regularly seen in some areas of Croatia. However, there are no data on the prevalence of infection and the clinical forms or geographic distribution of the disease. The aim of this study was to determine the seroprevalence of Streptococcus equi subspecies equi in horses resident in Croatia, in order to estimate the geographic distribution of infection. The study included 291 horse sera from the eight counties where the majority of Croatian horses are kept. Sera were tested by indirect ELISA (iELISA) for the presence of serum antibodies against S. equi pr...
Wijnker JJ, Bull S, Van Dijk P, Veenman JN, Rutten VP, Klein WR, Fink-Gremmels J.The detrimental effects of the pro-inflammatory cytokine TNF-alpha during equine acute abdominal disease are well known. Its pivotal role in many human diseases has led to various in-depth studies regarding its release mechanism, in particular by TNF-alpha converting enzyme (TACE). In this study we investigated the inhibitory effect of a TACE-inhibitor on cytokine release (TNF-alpha, IL-1alpha and IL-6) in three different cell models, including U937 cells, a recently established equine macrophage cell line, known as eCAS, and primary equine PBMC. The aim was to show the similarity of TNF-alpha...
Lyons ET, Drudge JH, Tolliver SC, Swerczek TW, Stamper S, Granstrom DE.Studies in a band of ponies harboring Population S benzimidazole-resistant small strongyles were initiated in 1974 and have continued for 18 years. Treatment (bimonthly) was with cambendazole for the first 4 years and with oxibendazole (OBZ) for the next 14 years. Data on the first 10 years have been published. The present investigation includes the last 8 years (4 October 1984-11 September 1992), which are the seventh through fourteenth years, of treatment with OBZ. Pre- and posttreatment mean counts of strongyle eggs (epg) and larvae (lpg) per gram of feces were determined biweekly during th...
Kwok WH, Leung DK, Leung GN, Wan TS, Wong CH, Wong JK.A rapid liquid chromatography-tandem mass spectrometry (LC-MS-MS) method was developed for the simultaneous screening of 19 drugs of different classes in equine plasma using automated on-line solid-phase extraction (SPE) coupled with a triple quadrupole mass spectrometer. Plasma samples were first protein precipitated using acetonitrile. After centrifugation, the supernatant was directly injected into the on-line SPE system and analysed by a triple quadrupole LC-MS-MS in positive electrospray ionisation (+ESI) mode with selected reaction monitoring (SRM) scan function. On-line extraction and c...
Freestone JF, Seahorn TL.Nutritional secondary hyperparathyroidism is associated with horses that are fed diets with an imbalance of calcium and phosphorus or diets containing oxalates. Clinical signs include a shifting lameness, with tenderness of the joints, reluctance to move, or a stiff, stilted gait. Some horses may have broadening of the nasal bones, enlargement of the maxilla and/or the mandible, or a ridge over the nasal bones. Diagnosis may include physical examination findings; analysis of feed; and clinical pathologic data, which may include normocalcemia, normal to increased serum phosphorus, and increased...
Liuti T, Daniel CR, Dixon PM, Reardon RJM.Cheek teeth (second through fourth premolars and first through third molars) diastema is a common and painful equine disorder caused by the absence of effective tight interdental contact between these teeth. Limited objective information is available on the angulation of equine cheek teeth that control dental drift or on mesial or distal equine cheek teeth drift that should normally prevent this disorder. Objective: To measure the angulation of the mesial and distal cheek teeth in horses of different ages, quantify age-related cheek teeth mesial and distal dental drift, and measure the cheek t...
Harkins JD, Carney JM, Meier M, Leak SC, Tobin T.Lipopolysaccharide (LPS), or endotoxin, is a component of the cell wall of gram-negative bacteria and is toxic to humans and animals. The GI tract of horses contains large numbers of endotoxins which may cause disease if gut wall integrity is compromised. The objective of this study was to develop a unique therapeutic approach to the treatment of endotoxemia with a sulfonyl analog of the alpha-phenyl-N-tert-butyl-nitrone (PBN) spin-trap molecule which may prevent the LPS-induced cytokine cascade. Following challenge with 55 mg/kg LPS, the survivability of ICR Swiss mice was significantly impro...
Knight PK.This study analysed the race day veterinary reports from harness racing meetings controlled by the New South Wales Greyhound and Harness Racing Regulatory Authority between 1 September 2008 and 30 June 2009. The findings of all prerace and postrace examinations were analysed, and the frequency of observations was recorded. Chi-square testing was used to determine whether the incidence of abnormalities differed between age groups and tracks. A total of 542 meetings were conducted during the period of the study, with veterinary examinations conducted at 395 of these meetings. A total of 520 vete...
Sheats MK, Burke MJ, Robertson JB, Fiebrandt KE, Fogle CA.Entrustable Professional Activities (EPAs) are units of activity that early-stage professionals perform in the workplace that necessitate simultaneous integration of multiple competencies. EPA #6 requires students to perform a common surgical procedure on a stable patient, including pre-operative and post-operative management. Castration is one of the most common surgeries performed by equine primary care practitioners and is considered an "entry-level competency" for veterinary graduates entering equine private practice, however, to our knowledge there are no equine castration models availabl...
O'Neill HD, Bladon BM.Records of horses admitted to a veterinary surgery in the UK for lameness investigation during 2000 to 2008 were reviewed. Twenty-one horses were identified with both scintigraphic and radiological evidence of enostosis-like lesions (ELLs), in which 68 individual foci of increased radiopharmaceutical uptake were confirmed in 57 long bones. The presenting lameness was attributed to ELLs in 15 of 21 (71 per cent) horses; the remainder were thought to be incidental findings. Five horses were subjected to a repeat examination, four of which showed the occurrence of new lesions in the same or diffe...
Tada M, Kobashigawa Y, Mizuguchi M, Miura K, Kouno T, Kumaki Y, Demura M, Nitta K, Kawano K.Equine lysozyme is a calcium-binding lysozyme and an evolutional intermediate between non-calcium binding c-type lysozyme and alpha-lactalbumin. We constructed a chimeric protein by substituting the fluctuating loop of bovine alpha-lactalbumin with the D-helix of equine lysozyme. The substitution affects the protection factors not only in the fluctuating loop but also in the antiparallel beta-sheet, the A- and B-helices, and the loop between the B-helix and the beta-sheet. Amide protons in these regions of the chimera are more protected from exchange than are those of bovine alpha-lactalbumin....
Mitchell SM, Zajac AM, Davis WL, Lindsay DS.Toxoplasma gondii is an important apicomplexan parasite of humans and other warm-blooded animals. Ponazuril is a triazine anticoccidial recently approved for use in horses in the United States. We investigated the mode of action of ponazuril against developing RH strain T. gondii tachyzoites in African green monkey kidney cells. Host cells were infected with 2.0 x 10(5) tachyzoites and treated with 5 microg/ml ponazuril. Cultures were fixed and examined by transmission electron microscopy 3 days after treatment. Ponazuril interfered with normal parasite division. This led to the presence of mu...
Stewart HL, Werpy NM, McIlwraith CW, Kawcak CE.To describe the effects of distal limb immobilization and remobilization in the equine metacarpophalangeal joint. Methods: Randomized, prospective experimental study. Methods: Eight healthy, skeletally mature horses. Methods: One forelimb of each horse was immobilized in a fiberglass cast for 8 weeks; this was followed by 12 weeks of a treadmill-based training program after the cast had been removed. Clinical examinations, radiography, computed tomography (CT), nuclear scintigraphy, MRI, and histomorphometry were used to examine the third metacarpal (MC3), proximal phalanx, proximal sesamo...
Millican L, Vanderstichel R, McClure J, MacMillan K.The objectives of this study were to determine the proportion of owners of horse farms in Prince Edward Island (PEI), Canada that were aware of the (CODE) and determine demographic factors associated with awareness. A questionnaire was completed by owners at fifty horse farms. In total, 38% of the farm owners were unaware of the CODE, 48% were aware, but were not familiar with its content and only 14% used the CODE when making decisions on caring for their horses. Owners of private stables were more aware of the CODE than owners of boarding stables. The CODE awareness varied between the three...
Sasaki M, Hayashi Y, Koie H, Yamaya Y, Kimura J, Manglai D, Kawashima S, Endo H, Yamamoto M.The domestic horse (Equus caballus) have the large symmetrical guttural pouches (the auditory tube diverticulum) formed by saccate bulge of the auditory tube. In this study, CT examination was carried out in the head of Przewalski's horse (Equus przewalskii), the only true wild horse living at present. As results of the examination, Przewalski's horse possessed the large symmetrical guttural pouches divided into medial and lateral compartments by the stylohyoid bone. Moreover, the right and left guttural pouches meet each other at the median part to form a thin septum. As CT sections get close...
Paweska JT.Clinical, virological and serological responses were investigated in five pregnant donkey mares after experimental exposure to the South African asinine-94 strain of equine arteritis virus (EAV), and the duration of maternal immunity to EAV was studied in their foals. In four intranasally inoculated mares, fever with maximum rectal temperatures of 39.1-40.7 degrees C was recorded 2-11 d after challenge. All the inoculated mares developed mild depression, and a serous ocular and nasal discharge; in three mares mild conjuctivitis was observed. The virus was recovered from the nasopharynx and fro...
Carpenter RS, Galuppo LD, Stover SM.To compare variables for screw insertion, pushout strength, and failure modes for a headless tapered compression screw inserted in standard and oversize holes in a simulated lateral condylar fracture model. Methods: 6 pairs of third metacarpal bones from horse cadavers. Methods: Simulated lateral condylar fractures were created, reduced, and stabilized with a headless tapered compression screw by use of a standard or oversize hole. Torque, work, and time for drilling, tapping, and screw insertion were measured during site preparation and screw implantation. Axial load and displacement were mea...
Easton-Jones CA, Estell KE, Magdesian KG.Information concerning clinical presentation, conditions associated with immune-mediated haemolytic anaemia (IMHA) and thrombocytopenia (IMTP) and outcome in equids is lacking. Previous case reports suggest that immune-mediated disease and neoplasia are associated. Objective: Characterise the clinical presentation, clinicopathologic data, underlying conditions, treatment and outcome of IMHA and IMTP cases in equids. We hypothesise that IMHA with concurrent thrombocytopenia occurs more often than IMHA or IMTP alone, and that neoplasia is commonly associated with these immune diseases and cases ...
