Journal of Equine Veterinary Science - Articles in Press

Alternative Intrabladder Manometry Technique for the Indirect Measurement of Intra-abdominal Pressure in Horses - Corrected Proof

2012-02-13

Abstract: Although indirect methods for estimating intra-abdominal pressure (IAP) have been extensively studied in humans, mainly for identification of IAP increments in critical care unit patients (life-threatening condition), little work has been performed in veterinary medicine, especially in horses. The standard method of acquisition of intrabladder pressure (IBP) in human subjects (fluid-filled system with no balloon distention) has been previously evaluated in horses with an unfavorable outcome. Therefore, we reexamined the previously performed method of IBP investigation in horses by using an air-filled intrabladder manometry system in female horses. Intrabladder pressure was estimated by air-filled balloon manometry in seven healthy adult mares. The results were compared with two sets of directly acquired IAP values obtained by right paralumbar puncture using an 8-G needle in seven horses. Direct IAP values were obtained at times unrelated to IBP measurement acquisitions, and three of the seven horses used (for direct IAP measurement) were different animals from the mares used for assessment of IBP. Both sets of IAP measurements yielded subatmospheric values (IAP1 = −10.5 ± 2.2 mm Hg; IAP2 = −11.6 ± 2.0 mm Hg). Slightly subatmospheric IBP values were also recorded in some mares, but the mean (±SD) IBP was 1.4 ± 2.0 mm Hg. There was no correlation between IBP and IAP. These results suggest that this indirect (IBP) method for estimating IAP is not applicable for female horses.

Effects of Steel and Aluminum Shoes on Forelimb Kinematics in Stock-Type Horses as Measured at the Trot - Corrected Proof

Elodie E. Huguet, Kylee J. Duberstein — 2012-02-10

Abstract: To meet the needs of sport horses, horseshoes of various styles and materials have been implemented to enhance performance. Steel shoes are commonly used for their affordability and longevity; however, the use of aluminum horseshoes is being adopted to satisfy the various requirements of certain equestrian activities. Owing to the importance of the allure of movement in many aspects of competitive riding, the lightweight nature of aluminum horseshoes has been recognized to accentuate foreleg action. By performing a repeated-measures crossover study on nine healthy stock-type horses, the effects of these two horseshoe types on forelimb action were analyzed at the trot using two-dimensional kinematics. Horses were trotted in hand for three repetitions over a distance of 50.1 meters on days 4, 18, 32, and 46 postshoeing for two 6-week shoeing cycles. Video footage was collected and analyzed using gait analysis software (EquineTec) for each repetition. The measured stride length, fetlock extension, elbow and knee range of motion, and minimum and maximum elbow angle remained constant between treatments. However, there was a significant treatment effect on minimum carpal angle and maximum hoof height, with aluminum shoes having a larger minimum carpal angle than those in steel shoes (P < .05) and a lower maximum hoof height (P < .05). An overall 3-degree difference in minimum carpal angle and approximate 2.5-cm difference in maximum hoof height was observed between treatments. This finding is of particular importance to performance horse disciplines for which a lesser degree of knee action is desirable.

Topographical Anatomy of the Equine M. Cutaneus Trunci in Relation to the Position of the Saddle and Girth - Corrected Proof

Alexandra van Iwaarden, Narelle C. Stubbs, Hilary M. Clayton — 2012-02-10

Abstract: The aim was to investigate the topographical anatomy of m. cutaneus trunci with reference to the position of the saddle and girth and its possible role in persistent sensitivity to girth pressure. The methodology involved dissections of 12 horse cadavers to describe the topography, attachments, morphological features, and thickness of the cutaneous muscles. M. cutaneus trunci was more variable in size and shape, especially the extent and curvature of its dorsal border, than the descriptions in anatomical texts indicate. In all horses, it extended far enough dorsally to lie directly underneath the weight-bearing panels of the saddle. The muscle was substantial in size, weighing 2.6-4.3 kg and having a 1.5- to 2.7-cm thickness in the girth region. Craniodorsally, it was adherent to the underlying fascia in the scapular region. Cranioventrally, m. cutaneus trunci had a distinct fascial attachment with the tendons of m. latissimus dorsi and m. teres major on the teres major tuberosity and the glenohumeral joint capsule. From this fascial attachment, the muscle fibers radiated caudally and were intimately connected to the skin by a diffuse fibrous network. Tactile stimulation of the skin overlying the cutaneous muscle is associated with a reflex muscular contraction that twitches the overlying skin (panniculus reflex). Failure to habituate to pressure of the tack in areas overlying the m. cutaneus trunci may result in continuous stimulation of the panniculus reflex, which could play a role in persistent sensitivity to girth pressure in some horses.

Population Pharmacokinetics of Tobramycin in Horses - Corrected Proof

Aneliya Haritova, Dinyo Bakalov, Huben Hubenov, Lubomir Lashev — 2012-02-10

Abstract: Population pharmacokinetics of tobramycin was investigated in 28 healthy horses, with an aim to assess interindividual variability in the disposition of the antibiotic. Additionally, a covariate model for improved prediction of the concentrations in a particular animal was developed. A two-compartmental model best described the data. The final population covariate regression model was based on relationships between body weight and central and peripheral volumes of distribution, and between creatinine clearance and systemic tobramycin clearance. The value of population systemic tobramycin clearance and its interindividual variation (CV) were 0.087 L.hr−1.kg−1 and 6.0%, respectively. The respective values for central and peripheral volumes of distribution were 0.652 L.kg−1 with CV of 17.7% and 1.56 L.kg−1 with CV of 4.5%. In horses with decreased glomerular filtration rate, lower tobramycin clearance is predicted with the population model that requires administration of lower dose than that accepted for treatment of horses with normal kidney function. Population pharmacokinetic analysis allows study of basic disposition of tobramycin in horses with sparse data. The prediction power of the regression model was improved by inclusion of covariables such as body weight and creatinine clearance. This model can be used in direct patient care for the construction of dosing strategy in individual clinical cases.

Environmental Impacts of Equine Operations: A U.S. Department of Agriculture Multistate Project - Corrected Proof

2012-01-30

Abstract: The U.S. Department of Agriculture supports agricultural research by encouraging the formation of multidisciplinary and multi-institutional teams. Project teams focus on agricultural issues related to profitability and economic and environmental sustainability. Recently, a U.S. Department of Agriculture project to study the impact of equine management and feeding practices on the environment was approved. The project, “NE-1041: Environmental Impacts of Equine Operations,” is a Northeast regional project but includes research and extension faculty from across the country. The project team includes representatives from Alabama, Connecticut, Kentucky, Louisiana, Maryland, Michigan, Minnesota, New Jersey, North Carolina, Pennsylvania, South Dakota, and Vermont. The goal of this project is to incorporate the best available data on horse management and feeding practices, manure storage and disposal, pasture and cropping management, soil and environmental quality, erosion control, and farm management practices to minimize negative impacts of equine operations on the environment. The specific objectives of the project are to assess existing data on environmental impacts of equine operations, identify gaps in current knowledge, conduct research when data are lacking or nonexistent, and incorporate existing and newly generated data into a systematic description of nutrient flow in soil, water, and air occurring on horse farms. Estimates will be made of pathogen transports and nitrogen (N)-, phosphorus (P)-, potassium (K)-, and energy (carbon)-loss potentials. In addition to identifying system-wide losses on equine farms, another goal of the project is to assist farmers and agricultural professionals in determining the value of equine management practices and other accepted best management practices.

Refinement of Culture Conditions for Maintenance of Undifferentiated Equine Umbilical Cord Blood Stem Cells - Corrected Proof

Sarah A. Reed, Sally E. Johnson — 2012-01-30

Abstract: Umbilical cord blood (UCB) was collected from Thoroughbred mares at foaling, and stem cells were isolated. UCB stem cells were cultured in growth media (GM), GM + Fibroblast Growth Factor 2, GM + Flt3/Thrombopoietin/c-Kit ligand, or conditioned media. Population doubling times (PDTs) were calculated. UCB stem cells cultured in standard GM exhibited faster PDTs (30.07 ± 1.59 hours) than those cultured in any treatment media. PDT was further accelerated by cultivation in GM on fibronectin (26.99 ± 1.57 hours)-, collagen I (26.21 ± 1.18 hours)-, or gelatin (27.32 ± 1.50 hours)-coated surfaces. Time in culture increased PDT regardless of media or substrata conditions. Because Oct4, nanog, KLF4, Sox2, and c-myc are implicated in embryonic stem cell pluripotency, total RNA was harvested from UCB stem cells as well as mouse ES cells and analyzed by reverse-transcription polymerase chain reaction. Both populations expressed all transcripts. The persistence of Oct4, nanog, and Sox2 expression in UCB stem cells was monitored over time in culture. Oct4 was detected throughout the duration of the experiment. Sox2 and nanog expression was lost with time in culture. Cells cultured on protein matrices maintained nanog expression longer than those on uncoated plasticware. These phenotypes remain unaffected by the type of culture matrix and FGF2. However, the plasticity markers are lost with serial passage.

First Report on the Frequency and Molecular Detection of Neuropathogenic EHV-1 in Turkey - Corrected Proof

2012-01-30

Abstract: There has been an increase in outbreaks of neuropathogenic equine herpesvirus-1 (EHV-1) in the United States and Europe. However, the presence and frequency of neuropathogenic EHV-1 in Turkish horses are not known at present. This study aimed to investigate the frequency of EHV-1 and neuropathogenic strains of EHV-1 in the Marmara Region of Turkey. Samples were analyzed for the presence of EHV-1 and neuropathogenic EHV-1 by real-time PCR TaqMan probe assays. Overall detection rate of EHV-1 was 45.5% (51 of 112). The detection rates were 70.5% (24 of 34) in aborted fetuses, 53.3% (8 of 15) in neonatal deads, 66.6% (4 of 6) in foals, 40% (2 of 5) in dead mares, and 25% (13 of 52) in living mares. Overall detection rate of neuropathogenic EHV-1 was 7.8% (4 of 51), and the real-time PCR results were confirmed by sequencing. Neuropathogenic strains of EHV-1 were detected in the brain and lung of two mares with neurological disease but without a history of abortion, in the brain of a foal that died of respiratory disorder, and in the nasal swab from a mare with a history of abortion. On histopathology, nonpurulent meningoencephalitis, hemorrhages, and vasculitis were seen in the brain. In conclusion, results of this study indicated, for the first time, that the neuropathogenic EHV-1 is circulating in the Marmara Region of Turkey. The results of this study also show that the current risk for non-neuropathogenic strains is high, whereas risk for the neuropathogenic EHV-1-G2254 strain seems to be low. As outbreaks of EHV-1 continue in the Marmara region of Turkey, surveillance for neuropathogenic EHV-1 genotype should be maintained.

Cervical Vertebral Osteomyelitis With Secondary Septic Arthritis of the Atlantoaxial Joint in a Foal: A Case Report - Corrected Proof

James R. Crabtree, Alec Jorgensen — 2012-01-30

Abstract: A 36-day-old, 100-kg Thoroughbred colt was presented with a sudden onset of abnormal head carriage and pyrexia. Radiography revealed an osteomyelitis of the vertebral body of the second cervical vertebra. Ultrasonography revealed abscessation in the region of the atlantoaxial articulation on the left side, and fluid aspirated from the abscess confirmed suppurative inflammation. Surgical management was not feasible on economic grounds, and therefore this case was managed with aggressive medical therapy based on the most likely pathogens involved. To provide prolonged antibiotic therapy within the client’s budget, the antibiotic flucloxacillin (Staphlex, 500 mg) was used at a dose of 10 mg/kg by mouth, three times daily. Thirty-eight days after first presentation, the foal was euthanized because of chronic pain and deterioration in neurologic signs. A diagnosis of chronic osteomyelitis of the body of the second cervical vertebra (axis) was made with concurrent septic arthritis of the atlantoaxial joint involving the articular surface of the first cervical vertebra (atlas) and cervical myelopathy of the spinal cord within the first two vertebrae. No pathogens were isolated post mortem. This is the first report to describe the use of flucloxacillin in a foal. Although the outcome was fatal, the medical therapy provided could be considered successful at sterilizing the bony lesion.

Equine Infectious Anemia: Active Surveillance in Central Italy 2007-2009 - Corrected Proof

Carmen Maresca, Eleonora Scoccia, Laura Faccenda, Jacopo Zema, Silva Costarelli — 2012-01-30

Abstract: Equine infectious anemia (EIA) is an infectious and potentially fatal viral disease of equids. EIA virus is usually transmitted from horse to horse by large biting insects, such as horseflies. The aim of this study was to evaluate the results of a national surveillance plan from 2007 to 2009 and evaluate the potential risk factors of EIA in horse populations in central Italy. In 2007, 18 of 6,773; in 2008, 30 of 7,940; and in 2009, 21 of 11,666 equines tested were seropositive for EIA. No statistical association was found between location or sex and the diagnosis of EIA. The seroprevalence rate (2007-2008-2009) was higher among older equids (older than 6 years) than among young (3 months to 5 years old) (P < .05). Likewise, the seroprevalence rate (2007-2008-2009) was higher among mules than among other horses (P < .05). Until 2007, the national equine register did not exist in Italy; therefore, it was difficult to measure the percentage of untested horses that presented a real but unquantified risk for continued EIA virus transmission. By introducing new laws governing the control and conducting active surveillance for EIA, it has been possible, in Italy, to develop a firm foundation of knowledge concerning the persistence and transmission of EIA and the risk factors and to better control the spread of this infection in horses.

Effect of Administration of Oxytocin During Diestrus on Corpus Luteum Function and Endometrial Oxytocin Receptor Concentration in Cycling Mares - Corrected Proof

Dirk K. Vanderwall, Desirée M. Rasmussen, Kevin G. Carnahan, Tracy L. Davis — 2012-01-30

Abstract: The objectives of this study were to (1) compare the effect of twice versus once daily administration of oxytocin on days 7-14 after ovulation on the duration of corpus luteum (CL) function and (2) determine the effect of oxytocin treatment on endometrial oxytocin receptor concentration in mares. In experiment 1, mares were randomly assigned to three groups on day 7: (1) untreated control group (n = 7), (2) twice daily oxytocin treatment group (n = 7), and (3) once daily oxytocin treatment group (n = 8). Oxytocin-treated mares received 60 U of oxytocin intramuscularly (IM) the respective number of times each day on days 7 through 14. One of seven control mares (14%), five of seven (71%) twice daily oxytocin-treated mares, and five of eight (63%) once daily oxytocin-treated mares had prolonged CL function. There was no significant difference in the proportion of mares with prolonged CL function between the two oxytocin-treated groups, and collectively, oxytocin treatment increased (P .1) between control and oxytocin-treated mares (1,465.7 ± 108 and 1,382.8 ± 108 fmol/mg protein [mean ± standard error of mean], respectively).

Periparturient Arterial Rupture in Mares: A Postmortem Study - Corrected Proof

Neil M. Williams, Uneeda K. Bryant — 2012-01-27

Abstract: There are limited reports characterizing the occurrence of rupture of uterine and other arteries associated with pregnancy in mares. Cases were retrieved from the records of horses submitted for necropsy to the University of Kentucky Veterinary Diagnostic Laboratory over a 15-year period (1993-2007). Five hundred thirteen horses were diagnosed with periparturient arterial rupture, representing 1.5% of the total equine necropsy cases. Arterial rupture was diagnosed predominately in older mares, with 78% of the horses being ≥15 years of age. Ruptures occurred most commonly during parturition but also were diagnosed before and after parturition. Additionally, during a consecutive 3-year period within this time interval, an extensive workup of cases was performed. In these 71 cases, the area of the arterial rupture was carefully dissected, and the location, size, and appearance of the arterial tear were determined. The uterine artery was the most commonly affected vessel. Although there was overlap, mares with uterine artery rupture tended to be older than those with rupture of other arteries. There was no predilection for the left or right sides, and the uterine artery rupture occurred most often in the first 20 cm from the origin.

Transcript Profiles of Hexose Transporters in the Equine Gastrointestinal Tract - Corrected Proof

2012-01-27

Abstract: To test the hypothesis that hexose transporter transcripts are in lower abundance in the large compared with the small intestine of the horse, mRNA abundance of genes encoding for hexose transporters was quantified in small and large intestinal segments of the horse. Four adult horses were euthanized, and mucosal samples were taken from two segments of the small intestine (distal jejunum [DJ] and ileum [IL]) and three segments of the large intestine (cecum [CE], left ventral colon [LVC], and left dorsal colon [LDC]). Transcript abundance of candidate hexose transporter genes was determined using reverse transcription quantitative polymerase chain reaction. Primers for genes SLC2A1, SLC2A2, SLC2A5, and SLC5A1, encoding for the hexose transporter proteins GLUT1, GLUT2, GLUT5, and SGLT1, respectively, were designed using gene sequences from GenBank. The 2ΔΔCT method was used to compare mRNA abundance of candidate genes in the IL, CE, LVC, and LDC with that of the DJ. Relative to the DJ, mRNA abundance of GLUT1 was not different in the IL, CE, and LVC, and increased (P ≤ .05) in the LDC. GLUT2, GLUT5, and SGLT1 gene expression was not different in the IL, and decreased (P ≤ .01) in the CE, LVC, and LDC, relative to the DJ. The decrease in expression for the majority of the hexose transporter genes in the large intestine indicates that it has less capacity for glucose, galactose, or fructose absorption compared with the small intestine of the horse.

The Effects of Selenium Source on Measures of Selenium Status of Mares and Selenium Status and Immune Function of Their Foals - Corrected Proof

2012-01-27

Abstract: The effect of organic and inorganic sources of selenium (Se) on measures of Se status of mares and their foals, Se concentrations of colostrum and milk, and indices of immune function of foals was studied. Twenty late-gestation Standardbred mares were randomly assigned to one of two groups. All mares received an identical balanced ration, except for the source of supplementary Se: one group received organic Se (Se yeast) and the other group received inorganic Se (sodium selenite), fed to deliver 0.3 mg/kg supplementary Se based on total ration dry matter. Mares received the experimental diet from 2 months before estimated due date until 1 month after foaling. Source of Se did not affect Se concentrations in maternal plasma, red blood cells, colostrum, or milk. At 1 month of age, foals from mares fed organic Se had higher red blood cell Se concentration than foals from mares fed inorganic Se (P < .05). Measures of immunity included serum immunoglobulin G concentration, lymphocyte proliferation in response to concanavalin A, and relative cytokine gene expression of stimulated lymphocytes (interferon gamma [IFNγ], interleukin [IL]-2, IL-5, IL-10, tumor necrosis factor alpha [TNFα]) and neutrophils (IL-1, IL-6, IL-8, IL-12, TNFα). Relative gene expression of IL-2, TNFα, and IFNγ by foal lymphocytes was associated with the source of Se supplementation provided to the mares. We conclude that the source of dietary Se provided to mares may influence the immune function of foals at 1 month of age through changes in relative gene expression of certain lymphocyte cytokines.

Fertility of Mares Inseminated With Frozen-Thawed Semen Processed by Single Layer Centrifugation Through a Colloid - Corrected Proof

2011-12-26

Abstract: The aim of this study was to determine whether there was an increase in pregnancy rates when frozen-thawed stallion semen was processed by single layer centrifugation (SLC) through a colloid before insemination. In addition, changes in semen parameters, including motility, were determined before and after SLC. Twenty light-horse mares (aged 3-16 years) and one Thoroughbred stallion (aged 16 years) having average fertility with fresh and cooled semen (>50% per cycle) and displaying a postthaw motility of >35% were used. Control mares were inseminated using 4- × 0.5-mL straws (200 × 106/mL) of frozen-thawed semen. Treatment mares were inseminated with 4 × 0.5 mL of frozen-thawed semen after processing by SLC. Pregnancy rates were compared using Fisher exact test, and continuous parameters were evaluated by a Student t test. The pregnancy rates at day 14 were not different for the mares inseminated with control versus SLC-processed semen, despite the difference in sperm number (171 × 106 ± 21, 59 × 106 ± 25 progressively motile sperm). After frozen-thawed semen was processed by SLC, the percentage progressively motile sperm improved (P < .05), and SLC processing resulted in a 21.8% recovery of spermatozoa. In summary, centrifugation of frozen-thawed semen through a single layer of colloid increased the percentage of motile spermatozoa, but did not improve pregnancy rates after deep horn insemination.

Efficacy of Deslorelin Acetate (SucroMate) on Induction of Ovulation in American Quarter Horse Mares - Corrected Proof

2011-12-23

Abstract: Equine clinicians rely on ovulation induction agents to provide a timed ovulation in mares for optimal breeding management. Numerous studies have been performed on the efficacy of human chorionic gonadotropin (hCG) to induce ovulation in the mare, but limited clinical data are available for the new deslorelin acetate product SucroMate. This study was designed to evaluate the efficacy of SucroMate (deslorelin) in comparison with hCG to induce ovulation. American Quarter horse mares (n = 256) presented to Colorado State University for breeding management were used in this study. Mares received either deslorelin or hCG when a follicle ≥35 mm was detected by transrectal ultrasound in the presence of uterine edema. Ultrasonographic examinations were subsequently performed once daily until ovulation was detected. Deslorelin was administered to 138 mares during168 estrous cycles, and hCG was given to 118 mares during 136 estrous cycles. Mares administered deslorelin had a significantly (P < .05) higher ovulation rate (89.9%) within 48 hours following drug administration than mares administered hCG (82.8%). There are no effects of season or age on ovulation rates in either treatment group. Twenty-one mares administered deslorelin and 11 mares administered hCG were monitored by transrectal ultrasound every 6 hours to detect ovulation as part of a frozen semen management program. Average intervals from deslorelin or hCG administration to ovulation were 41.4 ± 9.4 and 44.4 ± 16.5 hours, respectively. Results of this study indicate that SucroMate is effective at inducing a timed ovulation in the mare.

The Effect of Soaking on Carbohydrate Removal and Dry Matter Loss in Orchardgrass and Alfalfa Hays - Corrected Proof

Krishona Martinson, Hans Jung, Marcia Hathaway, Craig Sheaffer — 2011-12-23

Abstract: The objective of this research was to determine the impact of water temperature and soaking length on removal of nonstructural carbohydrate (NSC) fractions and dry matter (DM) from legume and cool-season grass hays. The experimental design was a randomized complete block with six replications. Hay types included bud and flowering alfalfa (Medicago sativa L.) and vegetative and flowering orchardgrass (Dactylis glomerata L.). Flakes were submerged for 15, 30, and 60 minutes in 25 L of cold (22°C) water, warm (39°C) water, and 12 hours in cold water, respectively. Water temperature at each soaking duration did not affect residual NSC fractions in alfalfa hays. Flowering and vegetative orchardgrass hays soaked for 30 and 60 minutes, respectively, in warm water had greater (P < .001) amounts of NSC fraction removal compared with soaking in cold water. Soaking bud and flowering alfalfa and vegetative orchardgrass hays for ≥15 minutes removed more NSC fractions compared with the control (P ≤ .005); however, soaking for 15-60 minutes resulted in similar NSC fraction removal. Conversely, in flowering orchardgrass hay, longer soaking times resulted in greater (P < .001) NSC fraction removal. Fructan removal in orchardgrass hay was greatest (P < .001) after soaking for 12 hours. DM losses were similar among hays after soaking for 15-60 minutes, but were greatest after soaking for 12 hours (P < .001). Soaking grass hay for 15-30 minutes is recommended to remove sufficient NSC fractions while minimizing DM losses.

Evaluation of Nociception, Sedation, and Cardiorespiratory Effects of a Constant Rate Infusion of Xylazine Alone or in Combination with Lidocaine in Horses - Corrected Proof

2011-12-23

Abstract: This study aimed to evaluate the effects of a constant rate infusion (CRI) of xylazine or xylazine in combination with lidocaine on nociception, sedation, and physiologic values in horses. Six horses were given intravenous (IV) administration of a loading dose (LD) of 0.55 mg/kg of xylazine followed by a CRI of 1.1 mg/kg/hr. The horses were randomly assigned to receive three treatments, on different occasions, administered 10 minutes after initiation of the xylazine CRI, as follows: control, physiologic saline; lidocaine low CRI (LLCRI), lidocaine (LD: 1.3 mg/kg, CRI: 0.025 mg/kg/min); and lidocaine high CRI (LHCRI), lidocaine (LD: 1.3 mg/kg, CRI: 0.05 mg/kg/min). A blinded observer assessed objective and subjective data for 50 minutes during the CRIs. In all treatments, heart and respiratory rates decreased, end-tidal carbon dioxide concentration increased, and moderate to intense sedation was observed, but no significant treatment effect was detected in these variables. Ataxia was significantly higher in LHCRI than in the control treatment at 20 minutes of infusion. Compared with baseline values, nociceptive threshold increased to as much as 79% in the control, 190% in LLCRI, and 158% in LHCRI. Nociceptive threshold was significantly higher in LLCRI (at 10 and 50 minutes) and in LHCRI (at 30 minutes) than in the control treatment. The combination of CRIs of lidocaine with xylazine produced greater increases in nociceptive threshold compared with xylazine alone. The effects of xylazine on sedation and cardiorespiratory variables were not enhanced by the coadministration of lidocaine. The potential to increase ataxia may contraindicate the clinical use of LHCRI, in combination with xylazine, in standing horses.

Evaluation of Urinary Variables as Diagnostic Indicators of Acute Kidney Injury in Egyptian Draft Horses Treated With Phenylbutazone Therapy - Corrected Proof

Maged R. El-Ashker, Hussein S. Hussein, Mahmoud G. El-Sebaei — 2011-12-16

Abstract: The present study was undertaken to evaluate the diagnostic significance of various urinary variables to detect acute kidney injury (AKI) in Egyptian draft horses treated with phenylbutazone (PBZ) therapy. Medical records of 52 draft horses, with a history of musculoskeletal painful conditions and treated frequently with various daily doses of injectable PBZ, were reviewed. Of those 52 horses, 38 were enrolled in this study. AKI was tentatively diagnosed based on thorough history and clinical findings and in conjunction with multiple biochemical screening tests. Accordingly, diseased horses were categorized into two main groups; the first group included 14 horses with prerenal azotemia, whereas the second group included 24 horses with renal azotemia. Biochemically, urinary malondialdehyde, urinary gamma-glutamyl transferase/creatinine (Cr) ratio, urinary protein/Cr ratio, urinary glucose, urinary sodium, fractional excretion of sodium, and renal failure index were significantly higher (P < .05) in horses of group 2 than those of group 1. However, values of urinary Cr, urine/plasma Cr ratio, urinary urea, and urine/plasma urea ratio were significantly decreased (P < .05) in horses of group 2. Analysis of receiver operating characteristic curve showed high sensitivity and specificity of most tested urinary variables as well as their derived indices for detection of AKI in diseased horses. Our findings suggest that the examined urinary variables as well as their ratios are helpful in documenting AKI associated with PBZ nephrotoxicity in Egyptian draft horses; however, their interpretation should be done in the light of the specific clinical setting and in conjunction with a thorough clinical and physical examination.

Acceptability of Teff Hay by Horses - Corrected Proof

2011-12-16

Abstract: Teff (Eragrostis tef) is a productive warm season annual grass. Because teff is relatively new to the horse industry in the United States, horses unaccustomed to teff hay were used in two sets of two-choice preference tests comparing teff with alfalfa hay or teff with timothy hay. A second experiment used mature mares to compare voluntary dry matter intake (VDMI) of teff hay and timothy hay. In the two-choice preference tests, horses preferred alfalfa hay and timothy hay to teff hay (P < .05). Horses preferred teff hay that was cut at an earlier stage of maturity and had lower concentrations of neutral detergent fiber and acid detergent fiber than teff hay cut at a later stage of maturity. In the VDMI experiment, four mares were fed teff hay and four mares were fed timothy hay for 17 days. Both hays had been harvested in the head stage of maturity. VDMI was measured during the last 10 days and was not different between the two groups of horses (P > .05). It was concluded that horses that are unfamiliar with teff may discriminate against it when it is offered simultaneously with alfalfa or timothy; however, if not given a choice, horses will consume approximately the same amount of mature teff as mature timothy. Additional studies are needed to compare VDMI of early maturity teff hay with other common hays.

Occurrence of Trypanosoma evansi in Horses in the State of Minas Gerais, Brazil - Corrected Proof

2011-12-15

Abstract: Ttrypanosomosis caused by Trypanosoma evansi is a condition that causes significant losses to farmers in endemic areas. This study aimed to report one case of trypanosomiasis in the municipality of Itabira, state of Minas Gerais, Brazil. In November 2010, on a farm with 16 horses, three horses had clinical signs of anemia, limb edema, weight loss, lameness, muscle atrophy, and incoordination of the hind limbs. Trypanosomosis was suspected, and the animals with clinical signs were treated with two doses of diminazene aceturate (7 mg/kg, intramuscular) every 7 days; the treated animals recovered from the clinical symptoms. Blood samples were collected from six horses on the farm, including the three treated animals, to perform polymerase chain reaction specific for T evansi. Four samples were polymerase chain reaction negative, including those collected from three treated horses. However, two other asymptomatic horses were positive for the parasite based on the molecular testing. Based on the results, we concluded that the initial clinical suspect of trypanosomosis was correct, and the treatment used was effective. Probably the disease was introduced to Minas Gerais State through a stallion, which acquired the infection in an endemic area in southern Brazil.

Haematic Mummification in a Mare With Twin Pregnancy - Corrected Proof

2011-12-15

Abstract: Mummification occurs when the fetus dies during the second or third trimester of gestation and remains in the uterine cavity because of the persistence of the corpus luteum or existence of another live fetus. Generally, the mummified fetus and fetal membranes undergo desiccation. The hematic process is similar, but the fetus appears like melted chocolate and becomes lodged between the uterus and chorion. This report describes the treatment of dystocia in a mare with twin pregnancy, with one fetus having undergone hematic mummification. Although difficult to diagnose, the possibility of a second fetus should be investigated in mares with dystocia.

A Comparison of Three Conventional Horse Feeders With the Pre-Vent Feeder - Corrected Proof

2011-12-15

Abstract: This study compared a feeder with molded cups on the bottom (Pre-Vent feeder) with a commonly used rubber tub and hanging bucket feeder to determine differences in time spent eating and feed wastage. Nine Quarter Horse geldings were fed a 12% crude protein pellet diet at 0.75% body weight twice daily from one of the three feeders twice daily for 3 days, and then switched to the next feeder, following a 3 × 3 replicated Latin square design (n = 9). The horses spent more time eating from the cup feeders (31.15 ± 1.43 minutes) than from bucket (19.39 ± 0.42 minutes) and tub (18.87 ± 0.49 minutes, P < .0001) feeders. When fed from cup feeder, horses dropped significantly less feed (3.2 ± 0.52%) of their ration than when fed from bucket (10.2 ± 1.75%) and from tub (7.0 ± 1.32%, P = .001) feeders. When the most wasteful horse was fed from the cup feeder, he lost a mean of 8.7% of his ration, compared with 32.8% when fed from the bucket, and 26.2% when fed from the tub feeders. The cup design is useful for increasing time spent eating and reducing feed wastage.

Preliminary Analysis of the Results of Selective Therapy Against Strongyles in Pasturing Horses - Corrected Proof

2011-12-15

Abstract: Control of horse parasites often omits application of measures to eradicate the free-living stages in pastures and frequently relies on chemotherapy only. Selective therapy was used for Spanish Sport horses grazing either in the same pasture (continuous) or in rotated meadows. In each group, equines exceeding a cutoff value of 300 strongyle eggs per gram of feces received ivermectin or moxidectin. Efficacy of the treatment was assessed by estimating reduction of fecal egg counts and the number of horses shedding parasite eggs (PHR). Coprocultures revealed presence of the cyathostomins Cyathostomum and Gyalocephalus spp. In all treated groups, a 100% value for both reduction of fecal egg counts and PHR against cyathostomins was obtained, and PHR values ranged from 100% to 12%. The longest strongyle egg reappearance period was observed in horses undergoing rotation grazing and receiving ivermectin (9 weeks), compared with a 6-week period recorded for the other treated equines. Our results seem to point that the efficacy of selective therapy in equine herds could be reduced if the horses with fecal egg counts below the threshold value (thus not receiving chemotherapy) remain grazing in the same pastures with the treated ones. It is strongly suggested that interested parties consider performing periodic fecal analyses to monitor fecal egg counts, together with the percentage of horses passing eggs in feces, to improve the effect of this procedure.

A Multiplex Polymerase Chain Reaction Assay for Direct Detection and Differentiation of β-Hemolytic Streptococci in Clinical Samples from Horses - Corrected Proof

Silvia Preziuso, Vincenzo Cuteri — 2011-12-15

Abstract: Streptococcus equi subspecies equi, S equi subspecies zooepidemicus, and S dysgalactiae subspecies equisimilis are β-hemolytic Streptococci, often isolated from horses with respiratory or genital diseases. The aim of this study was (i) defining and validating a multiplex polymerase chain reaction (PCR) protocol for identifying these Streptococci in bacterial cultures and for detecting them directly in equine clinical specimens, and (ii) defining and validating a cheap DNA extraction protocol for clinical specimens. When respiratory and genital samples from symptomatic and asymptomatic horses were tested by bacterial culture and by multiplex PCR, all the 150 samples culture-positive for S equi, S zooepidemicus, or S equisimilis were also positive by PCR. Of 150 culture-negative samples, 143 were negative by PCR. Seven samples were positive by PCR but negative by bacteriology. The multiplex PCR protocol described in this study is proven suitable for a sensitive, specific, and rapid detection and identification of S equi, S zooepidemicus, and S equisimilis in cultured bacterial colonies, as well as in clinical specimens from symptomatic or asymptomatic horses. The inclusion of internal control primers in the PCR protocol excludes false-negative results. A cheap DNA extraction method has been also validated for swabs, tracheal aspirates, bronchoalveolar lavage, and guttural pouches lavage samples.

Atypical Radiologic Appearance of a Second Cervical Vertebral Fracture in a Horse - Corrected Proof

Anna Ehrle, Sara Jones, Patricia Klose, Christoph Lischer — 2011-12-15

Abstract: This report presents the case of a 21-year-old Warmblood mare referred to the clinic with neurological dysfunctions and considerable signs of discomfort. A fracture of the caudal vertebral body of C2 with a very unusual radiographic appearance was diagnosed, and the mare was euthanized due to deterioration in neurological status. Histology revealed no evidence of neoplasia or pathological fracture.

Sick Neonatal Foals Do Not Demonstrate Evidence of Oxidative Stress - Corrected Proof

Martin Furr, Linda Frellstedt, Ray Geor — 2011-12-15

Abstract: Critical illness in humans is associated with alterations in oxidative stress and the concentration of antioxidant molecules; however, this association has not been examined in equine neonates. The purpose was to determine the concentration of various antioxidant molecules, as well as a marker of oxidative stress, in the serum and plasma of normal and sick neonatal foals and their dams. Results demonstrated that the concentration of selenium was less (61.71 vs. 77.93 ng/mL; P = .002) in sick versus healthy neonates, whereas the concentration of vitamin E was slightly higher in sick compared with healthy foals (4.36 vs. 3.17 mg/mL); however, this did not achieve statistical significance (P = .31). The vitamin E concentration was greater (5.37 vs. 3.43 mg/mL; P = .01) and serum selenium was less in sick mares (129.50 vs. 184.78 ng/mL; P = .0001) compared with healthy mares. In addition, the serum concentration of selenium is lower in neonates than in their dams in the perinatal period (70.10 vs. 173.34 ng/mL; P = .0001). Glutathione peroxidase activity was less in sick foals (7.04 nmol/min/mL) compared with healthy foals (9.13 nmol/min/mL) (P = .19), and 3-nitrotyrosine (3-NT) concentration/mg protein was less in sick foals versus healthy foals (geometric mean, 1.24 vs. 2.07 nmol 3-NT/mg protein). This difference did not achieve statistical significance (P = .09); however, when a subset of critically ill foals was examined, the assayed concentration of 3-NT/mg protein was even less (0.99 nmol 3-NT/mg protein) and did statistically differ from healthy foals (P = .03).

First Report of Methicillin-Resistant Staphylococcus aureus ST5 and ST398 from Purebred Lusitano Horses - Corrected Proof

Natacha Couto, Paula Tilley, Joana Simões, José P. Sales Luis, Constança Pomba — 2011-12-15

Abstract: Methicillin-resistant Staphylococcus aureus (MRSA) was first described in horses in 1996. The frequency of MRSA colonization in horses varies among European countries, but it is unknown in Portugal. The aim of this study was to screen for MRSA nasal carriage in a sample of horses entering the Equine Unit, Large Animal Veterinary Teaching Hospital of the Faculty of Veterinary Medicine, Lisbon, Portugal. Seventy-one horses were swabbed, and MRSA was identified by selective isolation on a chromogenic medium. Two S aureus isolates showed resistance to oxacillin (minimum inhibitory concentration >4 μg/mL) and contained the mecA gene. Both strains were isolated from purebred Lusitano horses that lived in farms with more than 20 equines. These MRSA strains represented two different clones: isolate FMVA3/10 was an MRSA sequence type ST5 with a staphylococcal cassette chromosome mec VI, coresistant to erythromycin and clindamycin; and isolate FMVA16/10 was sequence type ST398, with a staphylococcal cassette chromosome mec IV, coresistant to tetracycline, gentamicin, and trimethoprim. Isolate FMVA3/10 represents a human epidemic clone not previously reported among horses in Europe, which once again reinforces the fact that transmission of MRSA clones between horses and humans occurs. Isolate FMVA16/10 represents the first report of the detection of MRSA ST398 among horses in Portugal. Lusitano horses can carry animal and human MRSA in the nostrils, acting as reservoirs, which can potentially be transmitted to humans.

Various Circumstances Regarding Initial Allergen Exposure and Their Influence on Development of Insect Bite Hypersensitivity in Horses - Corrected Proof

Beatrix Sommer-Locher, Verena Endriss, Ella Fromm — 2011-11-21

Abstract: Insect bite hypersensitivity (IBH), an allergic reaction to the saliva of Culicoides, occurs in all horse breeds and is a severe problem. In this study, we aimed at exploring whether exterior conditions, such as duration of allergenic exposure during the first summer and age of the horses at the time of import, influence the development of IBH. Additionally, data were analyzed regarding the period IBH started after birth and after import. Datasets for 582 horses were collected. The horses were locally born Icelandic horses and horses of other breeds with IBH, as well as imported Icelandic horses, both affected and nonaffected. For locally born horses, time of birth and duration of allergen exposure during the first summer had no influence on the prevalence of IBH. The disease started mostly in their third year of life. The majority of the imported horses affected caught IBH during their first year in Central Europe. Older imported horses seemed to develop IBH quicker than younger animals. Animals imported in their first winter are exposed to the allergen when they are at least 7 months old. They experienced approximately the same low risk of developing IBH as locally bred horses. The risk of IBH increased with the horses’ age at import. From our data, we conclude that the period to develop successful immune tolerance goes beyond the perinatal phase and is longer than formerly supposed.

Comparison of Analgesic Effects of Caudal Epidural 0.25% Bupivacaine with Bupivacaine Plus Morphine or Bupivacaine Plus Ketamine for Analgesia in Conscious Horses - Corrected Proof

2011-11-21

Abstract: The aim of this study was to compare the effects of caudal epidural bupivacaine alone (BP), bupivacaine plus morphine (BPMP), and bupivacaine plus ketamine (BPKE) for perineal analgesia in horses. Each of the six saddle horses received a caudal epidural catheter and underwent 3 treatments: BP, 0.25% (0.04 mg/kg) bupivacaine hydrochloride without epinephrine; BPMP, 0.02 mg/kg of bupivacaine combined with 0.1 mg/kg of morphine-preservative free; and BPKE, 0.02 mg/kg of bupivacaine combined with 0.5 mg/kg of ketamine. The order of treatments was randomized. The cardiovascular system, respiratory rate, quality of analgesia, sedation, and motor blockade were assessed before drug administration (baseline), at 5, 10, 15, and 30 minutes, and every 30 minutes thereafter until loss of analgesia. The median time to onset of analgesia was 5 minutes after BP treatment, faster than after BPKE or BPMP treatments, which were 10 minutes and 15 minutes, respectively (P < .05). The BPMP treatment produced analgesia (315 minutes) for a longer duration than BP treatment (210 minutes) or BPKE treatment (240 minutes), in the regions of the tail, perineum, and upper hind limb in horses. All treatments presented mild sedation or motor blockade. There were minimal effects on the cardiovascular system and respiratory rate. BPMP may be preferable to a high dose of BP or BPKE. Caudal epidural BPMP can be an appropriate choice for regional perineal analgesia in horses.

Health Factors Associated with Microchip Insertion in Horses - Corrected Proof

2011-11-07

Abstract: The objectives of this study were to characterize the inflammatory response after microchip insertion, evaluate pain response and swelling at the microchip insertion site, and measure migration of the microchips. Eighteen mature Quarter Horse mares were separated by expected parturition dates and then assigned randomly to treatment groups. The microchip group (n = 7) had microchips inserted using a sterile needle and syringe; the sham group (n = 7) had a needle inserted but no microchip; and the control group (n = 4) had no insertion. The inflammatory response was measured over a 2-week period by measuring dermal temperature, response to pressure, and swelling at the insertion site and plasma serum amyloid A (SAA). For the migration component of the study, radiographs of the seven microchipped horses were taken over 6 months after insertion. These radiographs allowed measurement between a select vertebral point and the microchip. The microchip and sham insertion did not cause a detectable increase in temperature. Algometer readings, used to quantify pressure necessary to induce a pain threshold response, indicated that microchip insertion area was more sensitive than sham insertion at 2 hours, day 1, and day 3 post insertion. Visible swelling began 2 hours postinsertion and resolved by day 3. SAA concentrations were affected by day following insertion, but not by treatment group. Increases in SAA concentration could not be matched with local insertion reactions. Migration was not detected in any of the horses during the 6 months within a 0.7-cm margin of error.

Prognostic Significance of Oxidative Stress Markers in Colitis Associated with Phenylbutazone Administration in Draft Horses - Corrected Proof

2011-10-31

Abstract: The present study was carried out to assess the prognostic significance of oxidative stress markers in draft horses with colitis associated with phenylbutazone administration under field condition. For this purpose, a total of 40 native breed draft horses were studied. Based on case history, physical examination, and postmortem findings, diagnosis was made. According to the clinical outcome, horses were categorized into survivors and nonsurvivors. Clinically, there was significant association between nonsurvivors and anorexia (P < .01), stasis of intestinal motility (P < .01), melena (P < .01), and diarrhea (P < .001). Biochemically, malondialdehyde and nitric oxide showed a significant increase (P < .05) in nonsurvivors compared with survivors, whereas activities of superoxide dismutase showed a significant decrease (P < .05). Analysis of receiver operating characteristic curve indicated a high sensitivity and specificity of malondialdehyde, nitric oxide, and superoxide dismutase levels (P < .001) to predict the clinical outcome of colitis. Additionally, total protein and albumin showed a significant decrease in nonsurvivors compared with survivors; however, aspartate aminotransferase, sorbitol dehydrogenase, urea, and creatinine showed an increase (P < .05). The present results suggest that estimation of oxidative stress markers and antioxidant parameters may be useful predictors of the clinical outcomes of colitis associated with phenylbutazone administration in draft horses.

A Retrospective Study of 23 Cases of Coronary Band Separation Longer than 8 cm as a Sequel to Severe Laminitis - Corrected Proof

Robert A. Eustace, Susan L. Emery, Peter J. Cripps — 2011-10-31

Abstract: This article describes the clinical and radiological features, treatments, and outcomes from 23 equine cases that developed coronary band separation >8 cm long during a 23-year period. These equine cases were selected from a referral population of 175 cases that developed displacement of the distal phalanx relative to the hoof (DD). Time from onset of displacement of the distal phalanx to coronary band separation, time from coronary band separation to outcome, radiological measurements, presence of solar prolapse, description of the supracoronary contour, description of coronary band exudation, signalment, treatments used, and outcomes were recorded. Seven cases became sound and 16 were euthanased. The mean founder distance for horses that were euthanased was 15.2 mm and was significantly greater than for those that became sound (8.2 mm; P < .001). Using a cutoff of ≥11.8 mm, founder distance correctly predicted death for 100% (13/13) of cases and correctly predicted survival for 100% (7/7). The results of this study may help clinicians presented with similar cases to make more accurate prognoses in the future.

Comparison of Efficacy of Two Dose Rates of Histrelin to Human Chorionic Gonadotropin for Inducing Ovulation in Broodmares - Corrected Proof

2011-10-31

Abstract: Between February 15 and May 17, 2011, a total of 88 broodmares (10 maiden, 10 barren, and 68 foaling) maintained on pasture in southeast Texas were examined three times weekly (Tuesday, Thursday, Saturday) by transrectal palpation and ultrasonography. On Tuesday or Thursday, mares in estrus with uterine edema, a relaxed cervix, and a dominant follicle ≥34 mm in diameter were alternately assigned to treatment with the following: group (1) 2,500-unit human chorionic gonadotropin (hCG), intravenous; group (2) 1.0-mg BioRelease Histrelin (Biorelease Technologies, Lexington, KY), intramuscular; or group (3) 0.5-mg BioRelease Histrelin, intramuscular. Ovulation was confirmed by ultrasonographic examination. The percentage of mares ovulating within 2 days appeared to be similar between maiden, barren, and foaling mares, so responses for all mares were totaled for analysis. A nonsignificant trend for higher ovulation rates within 2 days was noted for both dose rates of histrelin compared with hCG treatment (31/37, 84%; 34/37, 92%; and 33/36, 92% for groups 1-3, respectively) (P = .45). Ovulatory responses appeared to improve for both products as the season progressed, yet no differences were detected between response rates to histrelin or hCG for any month (P ≥ .50). The use of 1.0- or 0.5-mg BioRelease Histrelin was found to be at least equally effective as hCG treatment for inducing ovulation within 2 days of treatment throughout the breeding season.

Procedure for the Transrectal and Transcutaneous Ultrasonographic Diagnosis of Pelvic Fractures in the Horse - Corrected Proof

Wade T. Walker, Natasha M. Werpy, Laurie R. Goodrich — 2011-10-31

Abstract: Recent advancements in the quality and availability of imaging modalities have allowed clinicians to diagnose fractures in horses with hindlimb lameness. Many imaging modalities aid in the diagnosis of pelvic fractures, including radiography, nuclear scintigraphy, computed tomography, and ultrasonography. Ultrasonography is an appropriate initial diagnostic tool when a pelvic fracture is suspected. The use of ultrasonography minimizes many of the risks and complications associated with the radiographic, scintigraphic, and computed tomographic evaluation of pelvic fractures, and is readily available to equine practitioners. This manuscript provides a detailed description of a complete transrectal and transcutaneous ultrasonographic examination of the equine pelvis. The described method has been effective in the diagnosis of pelvic fractures in a series of eight cases. Transrectal ultrasonography was found effective in revealing fractures of the ischiatic table, acetabulum, pubis, and ilium. Transcutaneous ultrasonography effectively identified fractures of the ilium, acetabular rim, femoral neck, greater trochanter, and a capital physeal fracture with a subluxated femoral head.

Laparoscopic Gonadectomy in Two Intersex Warmblood Horses - Corrected Proof

2011-10-21

Abstract: Two phenotypically female Warmblood horses were presented at the Clinic for Horses owing to stallion-like behavior. One mare had an enlarged clitoris, whereas the other one showed no signs of ambiguous external genitalia. In both cases, intra-abdominal testicles were removed by laparoscopy. Hormone status, cytogenetic evaluation, and histopathological examination of the gonads were performed. One animal was diagnosed as having XX disorder of sexual development; the other one, as male pseudohermaphrodite.

Application of Platelet-Rich Gel to Enhance Wound Healing in the Horse: A Case Report - Corrected Proof

Ilaria Iacopetti, Anna Perazzi, Vanni Ferrari, Roberto Busetto — 2011-10-21

Abstract: A large torn wound of the dorsal elbow region was observed in a 17-year-old Arabian mare. Surgical reconstruction was performed with the horse in standing sedation, but suture dehiscence occurred 2 days later. Autologous platelet-rich gel (PRG) was then applied to the wound every 3 weeks for a total of 3 administrations to accelerate good-quality healing. The wound had healed rapidly and completely within 5 months of the first PRG treatment, without chronic effects or formation of exuberant tissue granulation and with minimum scarring. This case report suggests that topical treatment with autologous PRG, as additional therapy, might be considered beneficial in the management of large-wound healing in horses, and it can be regarded as safe and inexpensive treatment that can be used in field.

Diagnosis and Surgical Management of Pythiosis in Draft Horses: Report of 33 Cases in Egypt - Corrected Proof

2011-10-21

Abstract: A total of 33 draft horses suffering from cutaneous pythiosis were referred to Mansoura Veterinary Teaching Hospital, Egypt, between October 2008 and January 2011. The animals presented ulcerative, granulomatous lesions located at the ventral aspect of the thorax (n = 10), abdomen (n = 14), forelimbs (n = 5), hind limbs (n = 2), and presternal region (n = 1) and at withers (n=1). The animals suffered from ulcerations composed of whitish yellow tissue having numerous draining tracts that discharge serosanguineous or bloody exudates. Initial diagnosis was based on location, gross lesion, and presence of kunkers. Histopathological evaluation revealed an eosinophilic granulomatous reaction associated with intralesional hyphae characteristic of Pythium insidiosum visualized by Gomori methenamine silver stain. The outcome of surgical excision revealed complete cure in 24 cases. Euthanasia was indicated in 9 cases.

Hematological and Biochemical Profiles in Peripartum Mares and Neonatal Foals (Heavy Draft Horse) - Corrected Proof

Takahiro Aoki, Mitsuo Ishii — 2011-10-21

Abstract: Peripartum mares and neonatal foals are physiologically unstable. Although hormonal changes around the parturition have been well studied in the field of endocrinology, hematological and biochemical changes have been studied little. The purpose of this study was to examine hematological and biochemical changes in peripartum mares and neonatal foals (n = 23; heavy draft horse). The number of white and red blood cells, hemoglobin concentration, hematocrit, mean cell volume, mean cell hemoglobin, mean cell hemoglobin concentration, platelet count in peripheral whole blood, and the concentration of glucose, nonesterified fatty acid, total cholesterol, triglyceride, total protein, albumin, globulin, blood urea nitrogen, creatinine, aspartate aminotransferase, gamma-glutamyltransferase, alkaline phosphatase, creatine kinase, iron, calcium, inorganic phosphate, magnesium, sodium, potassium, and chlorine in serum were measured. The main changes observed in peripartum mares suggested the following: (1) dehydration at the foaling, (2) physical stress by the foaling, (3) muscle damage by the foaling, and (4) change of energy metabolism associated with the beginning of lactation. The main changes observed in neonatal foals suggested the following: (1) dehydration (hemoconcentration) at the birth, (2) intake of colostrum, (3) beginning of urination, (4) functional change of hematopoiesis, (5) change of liver metabolism associated with the beginning of enteral nutrition, and (6) change of milk composition. This study revealed hematological and biochemical dynamics in peripartum mares and neonatal foals.

Myofibroblastic Sarcoma in the Limb of a Horse - Corrected Proof

2011-10-21

Abstract: A case of myofibroblastic sarcoma in the left hind limb is reported in a 4-year-old male, mixed-breed horse. This report includes the clinical signs, macroscopic and microscopic lesions, and the immunohistochemical findings related to this neoplasm.

Hoof Size and Symmetry in Young Catalan Pyrenean Horses Reared Under Semi-Extensive Conditions - Corrected Proof

Pere-Miquel Parés i Casanova, Maarten Oosterlinck — 2011-10-21

Abstract: Hoof balance and conformation have been researched extensively in performance horses. The aim of this study was to describe the solar length, width, area, and symmetry of fore and hind hooves of young Catalan Pyrenean horses (Cavall Pirinenc Català) reared under semi-extensive conditions and lacking any hoof care, trimming, or shoeing. Measurements were performed on the isolated limbs. Solar length, width, and surface area of 128 distal limbs obtained from 32 yearlings demonstrated no significant differences between left and right forelimbs or hind limbs for any variable (P = .413, .975, and .486, respectively). There were no significant differences between fore and hind limbs for length (P = .831), whereas the forehoof width and area were significantly larger than those of the hind limb (P < .001). Interindividual variability was low for hoof width and length (coefficient of variation, <10%) and slightly larger for solar area (coefficient of variation, <15%). All variables had very high left-right symmetry (≥98%). No relevant laterality could be identified (directional asymmetry indices <2%). Notwithstanding the absence of regular hoof care, young Catalan Pyrenean horses reared under semi-extensive conditions present homogenous hoof sizes and a high level of symmetry for hoof length, width, and solar area.

Deep Gluteal Abscess in a Zebra (Equus burchelli boehmi) - Corrected Proof

Indramani Nath, Subharaj Samantara, Susen K. Panda — 2011-10-21

Abstract: A male zebra aged about 7 years, weighing approximately 250 kg showed signs of lameness on its hindquarter. It was treated by the zoo veterinarians symptomatically, and it recovered. However, there was recurrence of the symptoms after 1 month. The animal was treated with fluid, electrolyte, antibiotic, and analgesic therapy. The hematology and serum biochemistry profiles were tested and found within the normal range. The animal was tranquilized, and physical and external examinations were conducted. Radiological examination of hoof ruled out any chances of laminitis or any other hoof deformities. Per-rectal examination along with flexion and extension of the hind limbs could not reveal any abnormalities. However, there was no improvement, and finally it died. Postmortem examination revealed an internal deep gluteal abscess. This is a rare report of deep gluteal abscess in a zebra. The difficulties encountered in diagnosing the case and its serious possible complications and possible methods of diagnosing have been described, which may help future equine and wildlife vets in diagnosing such cases successfully and may help in saving the precious lives of the patients suffering from such conditions.

A Modified One-Stage Repair of Third-Degree Rectovestibular Lacerations in Mares - Corrected Proof

Esam Mosbah — 2011-10-21

Abstract: A modified one-stage surgical repair was performed on eight mares that suffered from third-degree rectovestibular lacerations. The rectovestibular septum was reconstructed by three lines of sutures using polydioxanone. Primary healing was achieved in seven mares. Four mares got pregnant after the surgery, and no further injury was noticed at subsequent delivery. Complications of the currently used technique included pneumorectum (in one mare) and rectovestibular fistula (in another mare). The obtained results indicated that mares with third-degree rectovestibular lacerations are candidates for this modified one-stage technique with satisfactory outcome for subsequent fertility.

Dose-Response of Prolactin to Increasing Doses of the Dopamine Receptor Antagonist, Sulpiride, in Horses: Effect of Season in Mares and Stallions of Estradiol Pretreatment in Geldings - Corrected Proof

Sarah C. Clavier, Donald L. Thompson, Thomas J. Caltabilota, Pamela B. Mitcham — 2011-10-21

Abstract: Two experiments were performed to determine whether dopaminergic input to the adenohypophysis (1) differs across seasons in mares and stallions proportionally with changes in prolactin secretion and (2) is altered by estradiol administration in geldings. In experiment 1, prolactin responses to increasing doses of l-sulpiride in eight mares and eight stallions in March, June, September, and December were used to estimate the theoretical dose equivalent to 50% of maximal response. Prolactin areas increased (P .1) between groups. We conclude that dopaminergic input to the adenohypophysis of mares and stallions varies with season and that the stimulatory effect of estradiol on prolactin secretion is not associated with a decrease in dopaminergic input to the adenohypophysis.

The Relationship Between the Positive Identification of the Embryo Proper in Equine Pregnancies Aged 18-28 Days and its Future Viability: A Field Study - Corrected Proof

John R. Newcombe, Juan Cuervo-Arango — 2011-10-21

Abstract: Early embryonic loss (EEL) negatively affects the reproductive efficiency of equine reproduction. A sign of future EEL is when the embryo proper (EP) fails to develop within the embryonic vesicle after 30 days of gestation. The earlier the identification of impending EEL, the earlier the mare can be rebred to allow a second chance of pregnancy. The objectives of this study were to determine the percentage of embryonic vesicles with a visible EP at 18-28 days of gestation and to study the association between the presence/absence of the EP at different days of gestation and the future viability of the pregnancy. A total of 1,256 pregnancies were identified and followed by transrectal B-mode ultrasonography 12-45 days post ovulation in mares of the same Thoroughbred farm. The identification of the EP was attempted once during days 18-28. Pregnancy reconfirmation was performed on days 35-45. The percentage of vesicles with an EP increased gradually from days 18 (2.8%) to 21 (86.9%) (P < .05). From day 20 onward, the EEL rate of mares with vesicles without an EP was significantly higher (P < .05) than that of vesicles with a positive identification of an EP. In conclusion, the EP of the equine vesicle can be identified reliably with B-mode ultrasonography in the majority of mares (>71%) on day 20 of gestation. The lack of a positive identification of an EP from day 20 onward is associated with a higher EEL rate.

Effects of Topical Application of Sunflower-Seed Oil on Experimentally Induced Wounds in Horses - Corrected Proof

2011-09-19

Abstract: The objectives were to evaluate clinical and histopathological aspects of topical application of sunflower-seed oil (Helianthus annuus) on the healing process of experimentally induced wounds in lumbar and metacarpal areas of healthy horses. Six adult horses were used. Eight wounds were surgically produced on each horse: two 6.25-cm2 wounds cranial to the sacrum on each side of the lumbar region and two 2.89-cm2 wounds close to the proximal epiphysis of the metacarpus on the lateral aspect of each forelimb. Left side was used for macroscopic observations and right side for histopathological analysis. The experimental lesions were treated daily with sunflower-seed oil, whereas saline solution was used in control lesions. Macroscopic and histopathological analyses were performed on tissue harvested at 3, 7, 14, and 21 days. Complete healing time for all wounds was recorded. For lumbar region’s wounds, a contraction of 90.78% was recorded for those treated with oil and of 79.27% for control wounds after 21 days of treatment. For metacarpal region’s wounds, a contraction of 47.63% was recorded for wounds treated with oil and of 30.21% for control wounds. Wounds in the sunflower-seed oil treatment group had an elevation of polymorphonuclear cells, a newly formed vascular bed during the inflammatory phase, and a better alignment of collagen fibers during the remodeling phase. In conclusion, topical application of sunflower-seed oil was beneficial in the healing process of experimentally induced skin wounds in horses, with best results for treatment of lumbar wounds, making it a therapeutic option in equine wound healing.

Effect of Conditioning Horses Once, Twice, or Thrice a Week with High-Intensity Intermittent Exercise on v4 - Corrected Proof

2011-09-19

Abstract: Intensive short intervals of exercise are used to condition horses for racing. In this study, the effect of exercising horses one, two, or three times a week during 6 weeks using two intervals with near-maximal speed over 100 m on v4 (speed at which, under defined conditions, the blood lactate concentration reaches 4 mmol/L) and muscle thickness (MT) of supraspinatus and extensor carpi radialis was examined. Thoroughbreds (4-5 years of age) were exercised twice at near-maximal speed over 100 m, separated by a 10-minute period at walk, on dirt track during conditioning periods (CP) of 6-week duration. This exercise was undertaken once (six horses), twice (six horses), or thrice (five horses) a week during a CP. Before, every 2 weeks during, and 2 weeks after the CP, horses were subjected to a standardized exercise test to determine their v4. Before and after CP, the MT of the extensor carpi radialis and the supraspinatus was examined by ultrasonography. There was no differential effect of the number of weekly exercises on v4. Pooling the data of all horses, a decrease of v4 was found. The decrease became evident after the sixth week of conditioning. MT did not change. The results indicate that the examined exercise protocols could negatively impact racing performance of horses.