Veterinary therapeutics : research in applied veterinary medicine.
Discontinued
Publisher:
Veterinary Learning Systems,. Yardley, PA : Veterinary Learning Systems (2002)
Frequency: Quarterly
Country: United States
Language: English
Author(s):
Veterinary Learning Systems Co.
Start Year:2000 - 2010
Identifiers
| ISSN: | 1528-3593 (Print) 1528-3593 (Linking) |
| NLM ID: | 100936368 |
| (OCoLC): | 43369616 |
| LCCN: | 00211500 |
| Classification: | W1 VE938CP |
Field efficacy of ivermectin plus praziquantel oral paste against naturally acquired gastrointestinal nematodes and cestodes of horses in North America and Europe. The efficacy of an oral formulation of ivermectin plus praziquantel in the reduction of nematode and cestode egg counts in horses was assessed in 273 horses under field conditions at 15 sites in North America (n = 6) and Europe (n = 9). Horses were confirmed by fecal examination to have natural infections of strongyles (100%) and tapeworms (76%). Replicates of four horses were formed at each site, and in each replicate three animals received ivermectin (0.2 mg/kg body weight) plus praziquantel (1 mg/kg body weight) oral paste and one animal remained untreated or received vehicle paste. Fecal s...
Detection, quantification, metabolism, and behavioral effects of selegiline in horses. Selegiline ([R]-[-]N,alpha-dimethyl-N-2- propynylphenethylamine or l-deprenyl), an irreversible inhibitor of monoamine oxidase, is a classic antidyskinetic and antiparkinsonian agent widely used in human medicine both as monotherapy and as an adjunct to levodopa therapy. Selegiline is classified by the Association of Racing Commissioners International (ARCI) as a class 2 agent, and is considered to have high abuse potential in racing horses. A highly sensitive LC/MS/MS quantitative analytical method has been developed for selegiline and its potential metabolites amphetamine and methamphetamine...
Effects of epidural opioid analgesics on heart rate, arterial blood pressure, respiratory rate, body temperature, and behavior in horses. Heart rate, arterial blood pressures, respiratory rate, body temperature, and central nervous system excitement were compared before and after epidural administration of morphine (0.1 mg/kg), butorphanol (0.08 mg/kg), alfentanil (0.02 mg/kg), tramadol (1.0 mg/kg), the k-opioid agonist U50488H (0.08 mg/kg), or sterile water using an incomplete Latin square crossover design in five conscious adult horses. Treatments were administered into the first intercoccygeal epidural space. Significant (P <.05) reductions in respiratory rate were detected after epidural administration of morphine, alfent...
Detection, quantification, and pharmacokinetics of furosemide and its effects on urinary specific gravity following IV administration to horses. Furosemide is a potent loop diuretic used for the prevention of exercise-induced pulmonary hemorrhage in horses. This drug may interfere with the detection of other substances by reducing urinary concentrations, so its use is strictly regulated. The regulation of furosemide in many racing jurisdictions is based on paired limits of urinary SG (100 ng/ml). To validate this regulatory mechanism, a liquid chromatography/mass spectrometry/mass spectrometry method employing a solid-phase extraction procedure and furosemide-d5 as an internal standard was developed. The method was used to determine th...
Characterization of antimicrobial aerosols for administration to horses. A study was conducted to characterize the aerosols produced by a medical ultrasonic nebulizer using solutions containing antimicrobials appropriate for therapy of equine lower respiratory bacterial infections (gentamicin sulfate and ceftiofur sodium). Test aerosols were generated using an ultrasonic nebulizer and were analyzed using a laser diffraction aerosol particle analyzer. The aerosol was described in terms of the particle size distribution (volume median diameter), span (sample dispersion), and aerosol density (% volume). The particle size distribution and aerosol density of gentamicin ...
The detection and biotransformation of guanabenz in horses: a preliminary report. Guanabenz (2,6-dichlorobenzylidene-amino-guanidine) is a centrally acting antihypertensive drug whose mechanism of action is via alpha2 adrenoceptors or, more likely, imidazoline receptors. Guanabenz is marketed as an antihypertensive agent in human medicine (Wytensin tablets, Wyeth Pharmaceuticals). Guanabenz has reportedly been administered to racing horses and is classified by the Association of Racing Commissioners International as a class 3 foreign substance. As such, its identification in a postrace sample may result in significant sanctions against the trainer of the horse. The present ...
Increases in cytokine and antimicrobial peptide gene expression in horses by immunomodulation with Propionibacterium acnes. Immunomodulation with Propionibacterium acnes is used for prophylaxis of respiratory disease or in horses suffering from chronic pulmonary inflammation; however, the mechanism for this response is poorly understood. Semiquantitative reverse transcriptase-polymerase chain reaction assays were used to evaluate gene expression of interleukin (IL)-2, IL-10, interferon (IFN)-gamma, and NK-lysin in healthy horses treated with P. acnes. Findings in the study indicated that horses treated with a P. acnes-based immunomodulator exhibited increased IFN-gamma and NK-lysin gene expression in peripheral blo...
Comparison of serum and urinary concentrations of clenbuterol with and without concomitant administration of furosemide in horses. Furosemide is frequently used to control or prevent exercise-induced pulmonary hemorrhage in performance horses. The bronchodilating agent clenbuterol is also commonly used as a treatment for inflammatory airway disease in performance horses. Use of both medications is regulated by many racing authorities. The effects of concomitant administration of furosemide and clenbuterol on the pharmacokinetics of clenbuterol have not been well characterized. A study was designed to evaluate the influence of furosemide on serum and urine concentrations of clenbuterol after oral administration of clenbute...
Survival of foals with experimentally induced Rhodococcus equi infection given either hyperimmune plasma containing R. equi antibody or normal equine plasma. The purpose of this study was to determine if colostrum-deprived foals with experimentally induced Rhodococcus equi pneumonia have a decreased severity of the disease and decreased mortality rate when given hyperimmune (HI) R. equi antibody plasma (R. equi titer at least 100 % and virulence-associated protein A [VapA] at least 10000) prophylactically versus when given normal equine plasma (R. equi titer less than 20 % and VapA less than 160). Sixteen colostrum-deprived foals (R. equi titer less than 5 %) each received normal equine plasma in the first 24 hours of life (R. equi titer less than ...
Apparent ELISA detection times for albuterol after administration with the torpex equine inhaler device. Single doses of one, three, and six actuations (120 micro g albuterol/actuation) and multiple daily doses (six actuations per dose four times daily) for 5 days of aerosol albuterol sulfate were sequentially administered to each of six horses using an equine inhaler device (Torpex, 3M Animal Care Products, St. Paul, MN [corrected] and Boehringer Ingleheim Vetmedica, Inc., St. Joseph, MO [corrected]). A 2-week washout period was allowed between each dose. ELISA testing revealed no evidence of albuterol in urine at 24 hours after any single-dose administration. Results indicated that 48 hours or ...
Pharmacokinetics of erythromycin ethylsuccinate after intragastric administration to healthy foals. Plasma concentrations and pharmacokinetics of erythromycin and related compounds were determined after administration of erythromycin ethylsuccinate to six healthy male foals 3 to 5 months of age. Hay was withheld from the foals overnight and erythromycin ethylsuccinate (25 mg/kg of body weight) was administered intragastrically. Plasma erythromycin concentrations were determined at specific times after drug administration by high-performance liquid chromatography assay. Maximum peak plasma concentrations, time to maximum concentrations, area under plasma concentration versus time curves, elim...
Effect of topical ophthalmic latanoprost on intraocular pressure in normal horses. The ocular effects of latanoprost ophthalmic solution were evaluated in two studies, with eight horses in each study. One eye of each horse was treated with latanoprost ophthalmic solution once daily for 5 days, and the opposite eye received a control solution of sterile eyewash. Intraocular pressure and pupillary diameter were measured daily for 5 days after treatment. Latanoprost had no significant effect on intraocular pressure or pupillary diameter in normal horse eyes compared with control eyes in these studies. Placement of an eyelid nerve block resulted in significantly lower intraocula...
Effect of sulfadiazine and pyrimethamine on selected physiologic and performance parameters in athletically conditioned thoroughbred horses during an incremental exercise stress test. Following the regimen used to treat equine protozoal myeloencephalitis, sulfadiazine (20 mg/kg) and pyrimethamine (1mg/kg) were administered orally once daily to 12 physically conditioned Thoroughbred horses for 4 consecutive days. The horses were randomly assigned to two test groups in a crossover design, with each horse serving as its own control. A stepwise exercise stress test was conducted to exhaustion. No effect on athletic performance was observed, and only marginal effects were noted in some hematologic and serochemical measurements, including decreased total white blood cell counts, ...
Effect of flunixin meglumine on selected physiologic and performance parameters of athletically conditioned thoroughbred horses subjected to an incremental exercise stress test. Twelve clinically sound, healthy, athletically conditioned Thoroughbred horses were subjected to an incremental exercise stress test to determine the effects and period of detection of a single dose of flunixin meglumine (1.1 mg/kg by intravenous injection) in serum and urine by ELISA. Flunixin concentrations, performance, and hematologic and clinical chemical parameters were measured. All horses were rotated through four treatment groups of a Latin-square design providing for each horse to serve as its own control. Flunixin meglumine reduced prostaglandin F(1alpha) and thromboxane concentrati...
Evaluation of the effects of omeprazole on physiological indices of performance of horses during incremental treadmill exercise. Omeprazole is a proton-pump inhibitor recently approved in the United States for the treatment of gastric ulcer disease in horses. A study was designed to determine the effects of omeprazole treatment on the physiological indices of performance of horses during incremental treadmill exercise. In a crossover-design study carried out over 2 weeks, five horses completed standardized incremental exercise tests on a high-speed treadmill either with no treatment or treatment with omeprazole. No statistically significant effects of omeprazole were found on the mean maximum responses for specific oxyg...
Safety of an oral chondroprotective agent in horses. Six healthy, adult female horses were administered five times the minimum maintenance dose of an oral low-molecular-weight chondroitin sulfate, glucosamine HCl, and manganese ascorbate chondroprotective agent (Cosequin; Nutramax Laboratories, Inc., Edgewood, MD) daily for 35 days. Hematology, serum biochemistry, and synovial fluid parameters were assessed twice prior to administering the product and again at the end of the treatment period. Physical examinations performed daily throughout the study showed no abnormal clinical changes attributable to the product. All hematologic parameters meas...
Lymphocyte phenotype subsets in the cerebrospinal fluid of normal horses and horses with equine protozoal myeloencephalitis. The percentages of T-lymphocytes, lymphocyte subsets CD4+ and CD8+ T-cells, and lymphocyte adhesion molecule CD11a/CD18 were determined in the peripheral blood and cerebrospinal fluid (CSF) of seven normal horses and four horses with equine protozoal myeloencephalitis (EPM) using flow cytometry. There was a greater percentage of CD5+ cells in the CSF (79.0%) than in peripheral blood (67.0%), although this did not achieve statistical significance. Furthermore, the lymphocyte population in CSF comprises a significantly greater (P = .01) percentage of CD8+ T-cells, resulting in a decrease of the ...
Safety of ponazuril 15% oral paste in horses. Ponazuril, a triazine-derivative compound, is proposed as a treatment for equine protozoal myeloencephalitis caused by Sarcocystis neurona. Ponazuril 15% oral paste was administered to 24 horses at 0, 10, or 30 mg/kg body weight for either 28 or 56 days, representing zero, two, and six times the proposed dosage rate and one and two times the recommended duration of treatment, respectively. Serum chemistry analysis, coagulation profile, and hematology measurements were performed weekly and necropsy evaluations, including histopathology, were conducted for all animals at the end of the study. Mi...
The effects of pyrantel tartrate on Sarcocystis neurona merozoite viability. Sarcocystis neurona is the etiologic agent of equine protozoal myeloencephalitis, a neurologic disease of horses. The present study was designed to test the hypothesis that pyrantel tartrate can kill S. neurona merozoites growing in equine dermal cell culture. Sarcocystis neurona merozoites were exposed to a range of concentrations of pyrantel tartrate or sodium tartrate ranging from 0.001 to 0.01 M. Merozoites were then placed onto equine dermal cell cultures and incubated for 2 weeks to check for viability. At 1 and 2 weeks after inoculation, plaque counts were compared between treatments an...
Efficacy of ponazuril 15% oral paste as a treatment for equine protozoal myeloencephalitis. Equine protozoal myeloencephalitis (EPM) is a neurologic disease of horses most commonly caused by the protozoan parasite Sarcocystis neurona. Until recently the only treatment option was the combination of a sulfonamide with pyrimethamine. The present study was performed to assess the efficacy of ponazuril, an anticoccidial triazine-based compound, as a treatment for naturally occurring EPM. One hundred one horses with EPM were randomly allocated to treatment with ponazuril 15% oral paste at either 5 or 10 mg/kg body weight for 28 consecutive days. Horses were evaluated clinically and by anal...
Cerebrospinal fluid and serum concentrations of ponazuril in horses. Ponazuril was administered orally to 10 adult horses at 5 mg/kg body weight, once a day for 28 days. Blood was collected once a week from each horse from Days 0 through 35, daily from Days 35 through 42, and on Day 49. Cerebrospinal fluid (CSF) was also collected once a week from Day 0 through Day 49. Concentrations of ponazuril in the serum and CSF were determined, and pharmacokinetic calculations were performed. Ponazuril was readily absorbed following oral administration; and after 7 days of dosing, the serum concentration was 4.33 +/- 1.10 mg/L, and the mean CSF concentration was 0.162 +/-...
Pharmacokinetics of the bovine formulation of enrofloxacin (Baytril 100) in horses. Following approval of a concentrated injectable formulation of enrofloxacin for cattle (Baytril 100 Injectable, Bayer Corp. Agricultural Division, Shawnee Mission, KS), equine practitioners have started administering this preparation both parenterally and orally to horses, despite the lack of pharmacokinetic data in this species. Six healthy horses received enrofloxacin at 7.5 mg/kg both orally and intravenously, with the sequence being randomly assigned and at least 1 week of washout allowed between administrations. Blood samples were collected from each horse at various intervals after drug ...
Oral treatment with a nutraceutical (Cosequin) for ameliorating signs of navicular syndrome in horses. Fourteen horses with a progressive forelimb lameness of 3 to 12 months' duration, diagnosed as navicular syndrome, were selected from clinical cases admitted to Auburn University Equine Hospital for evaluation of the efficacy of an orally administered nutraceutical (Cosequin, Nutramax Laboratories, Inc., Edgewood, MD) for ameliorating clinical signs associated with naturally occurring navicular syndrome. Horses were randomly allocated to treatment with the nutraceutical or a placebo. Treatment was five scoops (16.5 g) of powder twice daily in the feed. The test group (n = 8) received a patente...
A 10-day toxicity study of toltrazuril 5% suspension in the horse. Equine protozoal myeloencephalitis (EPM) is a serious disorder of the nervous system of horses caused by Sarcocystis neurona. Recently, toltrazuril has begun to be used for treatment of EPM. The purpose of this study was to evaluate the potential toxicity of toltrazuril in horses when administered at a dose of 50 mg/kg for 10 days. Five horses were given 50 mg/kg of toltrazuril once daily for 10 days by nasogastric tube. Complete blood cell counts, serum chemistry values, and coagulation panels were evaluated before and after treatment; then a full postmortem examination was completed on day 1...
Cerebrospinal fluid and blood concentrations of toltrazuril 5% suspension in the horse after oral dosing. Toltrazuril 5% suspension (Baycox, Bayer Canada, Ontario, Canada) was administered to six adult horses followed by blood collection and assay to determine the concentration of toltrazuril and its principal metabolites, toltrazuril sulfone and toltrazuril sulfoxide. From this data, the maximum concentration (C(max)), elimination half-life (T 1/2), and mean residence times of the plasma were determined from standard pharmacokinetic formulas. After a single oral dose of 10 mg/kg body weight a rapid absorption was found, with a mean peak serum concentration of 11.17 mg/L at 18 hours. Elimination w...