@article{beachler_bailey_mckelvey_davis_edwards_diaw_vasgaard_whitacre_2016, title={Haemoperitoneum in a pregnant mare with an ovarian haematoma}, volume={28}, ISSN={["2042-3292"]}, DOI={10.1111/eve.12211}, abstractNote={SummaryHaemoperitoneum is a rarely reported but life‐threatening complication of a multitude of disease processes that can affect horses. This report describes an unusual case of haemoperitoneum in a pregnant mare attributed to a unilateral ovarian haematoma during early gestation. The mare was treated with supportive care and discharged 8 days after initial presentation. Following discharge, the mare maintained her pregnancy to term and delivered a live colt at 321 days of gestation.}, number={7}, journal={EQUINE VETERINARY EDUCATION}, author={Beachler, T. M. and Bailey, C. S. and McKelvey, K. A. and Davis, J. L. and Edwards, A. and Diaw, M. and Vasgaard, J. M. and Whitacre, M. D.}, year={2016}, month={Jul}, pages={359–363} }
 @article{bailey_heitzman_buchanan_bare_sper_borst_macpherson_archibald_whitacre_2012, title={B-mode and Doppler ultrasonography in pony mares with experimentally induced ascending placentitis}, volume={44}, ISSN={["2042-3306"]}, DOI={10.1111/j.2042-3306.2012.00658.x}, abstractNote={SummaryReasons for performing studyEarly, accurate diagnosis of ascending placentitis in mares remains a key challenge for successful treatment of the disease. Doppler ultrasonography has shown promise as a tool to diagnose pregnancy abnormalities and is becoming more available to equine clinicians. However, to date, no studies have prospectively compared this technique to standard B‐mode measurement of the combined thickness of the uterus and placenta (CTUP).ObjectivesThe objective of the current study was to compare Doppler and B‐mode ultrasonography for the detection of experimentally‐induced ascending placentitis in mares.MethodsEleven healthy pony mares in late gestation were used in this study. Placentitis was induced in 6 mares between Days 280 and 295, while 5 mares served as negative controls. All mares were intensively monitored until delivery. Fetal heart rate, CTUP, uterine artery blood flow (resistance index, pulsatility index, arterial diameter and total arterial blood flow) and physical examination findings were recorded at each examination. Mares with an increased CTUP above published values were treated in accordance with published recommendations. Foals and fetal membranes were examined at birth. Ultrasonographic parameters were compared between groups using ANOVA. Foal viability and histological presence of placentitis were compared using a Fisher's exact test.ResultsThe CTUP was increased above normal in 5 of 6 inoculated mares within 3 days after inoculation (P = 0.05). The sixth inoculated mare was excluded from subsequent data analysis. Uterine artery blood flow, physical examination findings and fetal heart rate were not different between groups. Gradual increases in CTUP, arterial diameter and total arterial blood flow were detected with increasing gestational age in the control mares (P = 0.02, P = 0.00001 and P = 0.00001, respectively).ConclusionThe CTUP, but not uterine blood flow, was different between groups (P = 0.00001). Recorded CTUP values for control pony mares were similar to previously published values for light breed horses.}, journal={EQUINE VETERINARY JOURNAL}, author={Bailey, C. S. and Heitzman, J. M. and Buchanan, C. N. and Bare, C. A. and Sper, R. B. and Borst, L. B. and Macpherson, M. and Archibald, K. and Whitacre, M.}, year={2012}, month={Dec}, pages={88–94} }
 @article{sper_whitacre_bailey_schramme_orellana_ast_vasgaard_2012, title={Successful reduction of a monozygotic equine twin pregnancy via transabdominal ultrasound-guided cardiac puncture}, volume={24}, ISSN={["0957-7734"]}, DOI={10.1111/j.2042-3292.2011.00254.x}, abstractNote={SummaryIn horses, twin pregnancy is pathological and represents a potentially life‐threatening condition to the mare and foal. Twinning occurs in approximately 2% of pregnancies. Of these, the majority of cases are dizygotic twins, resulting from 2 ovulations and monozygotic twins are rare. A 12‐year‐old Quarter Horse mare was presented for breeding management with shipped cooled semen and embryo transfer. Seven days post ovulation, a single late morula/early blastocyst was recovered and transferred immediately to a recipient mare. Thirty‐six days after transfer, transrectal ultrasound examination revealed the presence of 2 embryos. A transcutaneous reduction of one of the fetuses was performed successfully at 128 days of gestation. This report is the first to describe a successful reduction of monozygotic twins by transcutaneous ultrasound‐guided cardiac puncture.}, number={2}, journal={EQUINE VETERINARY EDUCATION}, author={Sper, R. B. and Whitacre, M. D. and Bailey, C. S. and Schramme, A. J. and Orellana, D. G. and Ast, C. K. and Vasgaard, J. M.}, year={2012}, month={Feb}, pages={55–59} }
 @article{bailey_sper_schewmaker_buchanan_beachler_pozor_whitacre_2012, title={Uterine artery blood flow remains unchanged in pregnant mares in response to short-term administration of pentoxifylline}, volume={77}, ISSN={["1879-3231"]}, DOI={10.1016/j.theriogenology.2011.08.018}, abstractNote={The objective of this study was to use Doppler ultrasound technology to determine whether pentoxifylline administration increased uterine blood flow in normal pregnant pony mares. Thirteen pregnant pony mares between 18 and 190 d of gestation (mean ± SEM, 101 ± 55) were utilized for the study during two trial periods. In each trial, pentoxifylline (17 mg/kg by mouth every 12h, diluted in syrup) was administered to half of the mares for 3 d, while the other mares were treated with syrup only. Doppler measurements were obtained from the right and left uterine arteries from each mare for 2 d prior to treatment and throughout the treatment period. The mean Resistivity Index (RI), Pulsatility Index (PI), Uterine Artery Diameter (D), and Total Arterial Blood Flow (TABF) from each day were compared over time and between groups. Administration of pentoxifylline did not alter uterine blood flow parameters compared with controls (values for all treatment days combined were RI: 0.517 ± 0.014 vs 0.543 ± 0.016; PI: 0.876 ± 0.048 vs 0.927 ± 0.057; D: 0.388 ± 0.018 vs 0.379 ± 0.023 cm; and TABF: 35.26 ± 7.38 vs 30.73 ± 5.29 mL/min). Uterine blood flow increased over the course of the 5 d study, irrespective of treatment, and was higher in mares of greater gestational age than in early gestational mares (RI: r(2) = 0.35; PI: r(2) = 0.37; D: r(2) = 0.66; and TABF: r(2) = 0.67 - P < 0.00001). We concluded that any immediate benefits of pentoxifylline administration in the pregnant mare were not mediated through enhanced uterine artery blood flow.}, number={2}, journal={THERIOGENOLOGY}, author={Bailey, C. S. and Sper, R. B. and Schewmaker, J. L. and Buchanan, C. N. and Beachler, T. M. and Pozor, M. A. and Whitacre, M. D.}, year={2012}, month={Jan}, pages={430–436} }
 @article{schramme_pinto_davis_whisnant_whitacre_2008, title={Pharmacokinetics of carbetocin, a long-acting oxytocin analogue, following intravenous administration in horses}, volume={40}, ISSN={["0425-1644"]}, DOI={10.2746/042516408X334343}, abstractNote={Summary Reason for performing study: Current therapy protocols to treat persistent post mating endometritis and retained fetal membranes in mares typically include the administration of ecbolic drugs. Evaluation of the pharmacokinetics and tolerability of carbetocin, a long‐acting oxytocin analogue, after i.v. administration is required. Objectives: To determine the pharmacokinetic parameters (principally half‐life) of carbetocin in horses. Methods: Five mature mares and one gelding received 0.175 mg carbetocin i.v. All animals were monitored periodically throughout the study for elevation in rectal temperature, heart rate, respiratory rate and signs of pain or discomfort. Plasma samples were collected for determination of carbetocin concentrations by radioimmunoassay. Results: Administration of carbetocin was well tolerated by all horses and its half‐life was 17.2 min. Conclusions: The half‐life of carbetocin is greater than that previously reported for oxytocin (6.8 min). Potential relevance: Carbetocin is an attractive alternative to oxytocin therapy in broodmare management.}, number={7}, journal={EQUINE VETERINARY JOURNAL}, author={Schramme, A. R. and Pinto, C. R. F. and Davis, J. and Whisnant, C. S. and Whitacre, M. D.}, year={2008}, month={Nov}, pages={658–661} }
 @article{papich_van camp_cole_whitacre_2002, title={Pharmacokinetics and endometrial tissue concentrations of enrofloxacin and the metabolite ciprofloxacin after i.v. administration of enrofloxacin to mares}, volume={25}, ISSN={["1365-2885"]}, DOI={10.1046/j.1365-2885.2002.00434.x}, abstractNote={Enrofloxacin was administered i.v. to five adult mares at a dose of 5 mg/kg. After administration, blood and endometrial biopsy samples were collected at regular intervals for 24 h. The plasma and tissue samples were analyzed for enrofloxacin and the metabolite ciprofloxacin by high‐pressure liquid chromatography. In plasma, enrofloxacin had a terminal half‐life (t½), volume of distribution (area method), and systemic clearance of 6.7 ± 2.9 h, 1.9 ± 0.4 L/kg, and 3.7 ± 1.4 mL/kg/min, respectively. Ciprofloxacin had a maximum plasma concentration (Cmax) of 0.28 ± 0.09 μg/mL. In endometrial tissue, the enrofloxacin Cmax was 1.7 ± 0.5 μg/g, and the t½ was 7.8 ± 3.7 h. Ciprofloxacin Cmax in tissues was 0.15 ± 0.04 μg/g and the t½ was 5.2 ± 2.0 h. The tissue:plasma enrofloxacin concentration ratios (w/w:w/v) were 0.175 ± 0.08 and 0.47 ± 0.06 for Cmax and AUC, respectively. For ciprofloxacin, these values were 0.55 ± 0.13 and 0.58 ± 0.31, respectively. We concluded that plasma concentrations achieved after 5 mg/kg i.v. are high enough to meet surrogate markers for antibacterial activity (Cmax:MIC ratio, and AUC:MIC ratio) considered effective for most susceptible gram‐negative bacteria. Endometrial tissue concentrations taken from the mares after dosing showed that enrofloxacin and ciprofloxacin both penetrate this tissue adequately after systemic administration and would attain concentrations high enough in the tissue fluids to treat infections of the endometrium caused by susceptible bacteria.}, number={5}, journal={JOURNAL OF VETERINARY PHARMACOLOGY AND THERAPEUTICS}, author={Papich, MG and Van Camp, SD and Cole, JA and Whitacre, MD}, year={2002}, month={Oct}, pages={343–350} }
 @article{cavalieri_farin_kinder_van camp_whitacre_washburn_britt_2001, title={Ovarian follicular development following administration of progesterone or aspiration of ovarian follicles in Holstein cows}, volume={55}, ISSN={["1879-3231"]}, DOI={10.1016/S0093-691X(01)00445-9}, abstractNote={The objective of this study was to compare the effects of administration of a single injection of progesterone (P4) and follicle aspiration on Day 7 of the estrous cycle on the timing and synchrony of follicular wave emergence, time of ovulation, and concentrations of P4, estradiol and FSH in Holstein cows. Twenty cows were assigned to 4 groups (n=5 cows per group) in a 2 by 2 factorial arrangement. Cows were treated on Day 7 (Day 0 = estrus) of the estrous cycle with either sham follicular aspiration and an oil vehicle administered intramuscularly (control), aspiration of ovarian follicles (aspiration), 200 mg of P4 im, or aspiration and 200 mg of P4 im (aspiration + P4). On Day 11, PGF(2alpha)(25mg) was administered to all groups. Synchrony of ovulation was less variable in each of the treatment groups compared with the control group (P<0.05), whereas ovulation was delayed in cows in the P4 group (P<0.05). Day of follicular wave emergence was delayed in the cows of the P4 group compared with cows in the aspiration and aspiration + P4 groups (P<0.01), whereas variability in wave emergence was less among both groups of aspirated cows compared with the cows in the control group (P<0.01). More follicles 4 to 7 mm in diameter were detected in the 2 aspiration groups compared with the cows in the control and P4 group (P<0.05). No difference was detected among groups in the maximum concentration of FSH associated with follicular wave emergence. We conclude that both the administration of P4 and the aspiration of follicles on Day 7 of the estrous cycle improves the synchrony of ovulation when luteolysis is induced on Day 11 and results in similar concentrations of FSH at the time of follicular wave emergence, but the timing of wave emergence and the number of follicles post-emergence differ.}, number={3}, journal={THERIOGENOLOGY}, author={Cavalieri, J and Farin, PW and Kinder, JE and Van Camp, SD and Whitacre, MD and Washburn, SP and Britt, JH}, year={2001}, month={Feb}, pages={805–821} }
 @article{van camp_papich_whitacre_2000, title={Administration of ticarcillin in combination with clavulanic acid intravenously and intrauterinely to clinically normal oestrous mares}, volume={23}, ISSN={["1365-2885"]}, DOI={10.1046/j.1365-2885.2000.00297.x}, abstractNote={Ticarcillin and clavulanic acid (potassium clavulanate) were administered to normal oestrous mares intravenously (i.v.) at a dose of 50 and 1.67 mg/kg for ticarcillin and clavulanate, respectively. In a crossover design, the same drugs were administered intrauterine (i.u.) at a dose of 12.4 and 0.4 mg/kg for ticarcillin and clavulanate, respectively. The i.u. dose was administered in 100 mL of saline solution. Endometrial tissue biopsies and plasma samples were collected after drug administration for the determination of ticarcillin and clavulanate concentrations by high-pressure liquid chromatography and pharmacokinetic calculations. After i.u. administration both drugs were poorly absorbed into the plasma. The ticarcillin half-life from tissue and plasma was short after i.v. administration. Although concentrations in tissue were higher after i.u. administration than i.v., concentrations of ticarcillin declined rapidly, which would necessitate frequent treatment in order to maintain drug concentrations above the minimum inhibitory concentrations (MIC) throughout the treatment period. Clavulanate concentrations in tissue were either low or persisted for only a short time after administration via either route. It appears that addition of clavulanate to the formulation for treatment of i.u. infections in mares is of questionable value based on these concentrations.}, number={6}, journal={JOURNAL OF VETERINARY PHARMACOLOGY AND THERAPEUTICS}, author={Van Camp, SD and Papich, MG and Whitacre, MD}, year={2000}, month={Dec}, pages={373–378} }
 @article{whitacre_yates_van camp_meuten_1992, title={Detection of intravaginal spermatozoa after natural mating in the bitch}, volume={21}, DOI={10.1111/j.1939-165x.1992.tb00589.x}, abstractNote={SummaryMismating is one of the most frequently presented reproductive problems presented to veterinarians. Confirming whether or not a mismating has occurred is necessary to determine if therapy will be instituted. Detection of spermatozoa in the vagina is irrefutable evidence of copulation; however, absence of sperm in a vaginal cytology cannot rule out coitus. In order to improve detection of spermatozoa post‐coitus, a prospective study was initiated utilizing natural breedings of purebred beagles.}, number={3}, journal={Veterinary Clinical Pathology}, author={Whitacre, M. D. and Yates, D. J. and Van Camp, S. D. and Meuten, D. J.}, year={1992}, pages={85} }
 @article{whitacre_tate_estill_vancamp_1991, title={TRANSENDOSCOPIC ND - YAG LASER ABLATION OF VAGINAL SEPTA IN A BITCH}, volume={20}, ISSN={["0161-3499"]}, DOI={10.1111/j.1532-950X.1991.tb01257.x}, abstractNote={A vaginal septum was diagnosed in an English bulldog bitch during routine estrous cycle staging. The septum extended 16 cm from the vestibulo‐vaginal junction to just caudal to the cervix. The septum was removed by two applications of an Nd:YAG laser via a flexible fiberoptic endoscope. Complete healing occurred over a 5‐week period and was uneventful. The bitch was bred and subsequently delivered four puppies vaginally. Transendoscopic laser ablation provided a noninvasive approach to surgically remove a vaginal septum in the dog.}, number={4}, journal={VETERINARY SURGERY}, author={WHITACRE, MD and TATE, LP and ESTILL, CT and VANCAMP, SD}, year={1991}, pages={257–259} }