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 |
Antimicrobial activity of tulathromycin and 14 other antimicrobials against virulent Rhodococcus equi in vitro. This study determined the antimicrobial activity of tulathromycin against Rhodococcus equi in vitro. Ninety-eight virulent isolates of R. equi from equine clinical cases were examined, of which 20 isolates were macrolide resistant. A custom 96-well antimicrobial susceptibility testing plate was used, allowing 14 additional antimicrobials to be tested against R. equi. Isolates were cultured with various concentrations of antimicrobials, and minimal inhibitory concentration (MIC) values were determined. Tulathromycin was found to have poor activity in vitro against R. equi isolates susceptible o...
Single-dose oral pharmacokinetics of pergolide mesylate in healthy adult mares. Pituitary pars intermedia dysfunction (PPID) is probably the most common disease of geriatric horses. Affected horses show a variety of clinical signs, including hirsutism, polyuria/polydipsia, immunosuppression, muscle wasting, and laminitis. The most common treatment for PPID is pergolide, a dopamine agonist; however, there are no pharmacokinetic data about the use of this drug in horses. This article describes a study designed to address this complete lack of pharmacokinetic information. The pharmacokinetics of pergolide are described in a small group of relatively young, healthy mares (n =...
Pilot immunization of mice infected with an equine strain of Corynebacterium pseudotuberculosis. This pilot study evaluated protection of an equine autogenous bacterin-toxoid vaccine against Corynebacterium pseudotuberculosis infection. Twenty-four BALB/c mice were inoculated with two doses of bacterin-toxoid vaccine or two injections of a placebo. Clinical, microbiologic, and pathologic outcomes were assessed after intradermal infection with one of two equine-origin C. pseudotuberculosis strains. Mice receiving bacterin-toxoid from fast-growing C. pseudotuberculosis showed significant protection from challenge infection, as evidenced by a higher survival rate, fewer gross and histopathol...
Effects of top-dress formulations of suxibuzone and phenylbutazone on development of gastric ulcers in horses. Eighteen mature, healthy horses were divided into three groups (six per group) receiving either no treatment, 15 consecutive days of phenylbutazone (PBZ), or 15 consecutive days of suxibuzone (SBZ) at recommended label doses. Horses underwent endoscopy before and after the treatment period and were assigned gastric ulcer scores. Gastric ulcer number and severity scores were similar across treatment groups. These findings suggest that when administered at the recommended label dose for 15 days, neither PBZ nor SBZ causes an increase in the number or severity of gastric ulcers over what would be...
Ceftiofur susceptibility of Streptococcus equi subsp zooepidemicus isolated from horses in North America between 1989 and 2008. In vitro activity of ceftiofur and six other antimicrobial agents was assessed for 516 Streptococcus equi subsp zooepidemicus isolates collected from horses with lower respiratory tract infections in North America in 2007 and 2008 and 239 equine S. equi subsp zooepidemicus isolates received from US and Canadian veterinary diagnostic laboratories between 1989 and 2007. The lowest concentration of ceftiofur inhibiting the growth of 90% of the isolates (MIC90) was 0.12 microg/ml for both groups of isolates. The Clinical and Laboratory Standards Institute susceptible breakpoint set for ceftiofur a...
Evaluation of intraoperative culture results as a predictor for short-term incisional complications in 49 horses undergoing abdominal surgery. This study evaluated bacterial isolates obtained during abdominal surgery and their relationship to short-term incisional complications. Samples of peritoneal fluid and from resection and/or enterotomy sites from 49 horses were cultured, with 96% having at least one positive culture result. The most common isolates were Escherichia coli, Streptococcus spp, and Enterococcus spp. Horses with small intestinal resections were more likely to grow obligate anaerobes and enteric organisms. Horses with small intestinal lesions (+/- resection) were more likely to grow enteric organisms and less likely ...
In vitro susceptibility of ceftiofur against Streptococcus equi subsp zooepidemicus and subsp equi isolated from horses with lower respiratory disease in Europe since 2002. In vitro activity of ceftiofur and six other antimicrobial agents was evaluated against 79 Streptococcus equi subsp zooepidemicus isolates collected from horses with respiratory disease in Europe during 2007 and 2008. In addition, the in vitro activity of ceftiofur and other antimicrobial drugs was assessed against 59 S. equi subsp zooepidemicus and 49 S. equi subsp equi isolates collected by veterinary diagnostic laboratories in Europe from 2002 to 2006. The lowest concentration of ceftiofur that inhibited the growth of 90% of the isolates (MIC90) was 0.12 microg/ml, with the Clinical Laborat...
Evaluation of the palatability of three nonsteroidal antiinflammatory top-dress formulations in horses. The efficacy of top-dress antiinflammatory drugs ultimately depends on a patient's willingness to consume treated feed. The current study compares the palatability of two phenylbutazone top-dress formulations (Equipalazone Powder, Dechra Pharmaceuticals, and Pro-Dynam, VetXX, Ltd.) and a suxibuzone top-dress formulation (Danilon Equidos, Janssen Animal Health). Results of a three-period, crossover study on 18 healthy horses showed that Pro-Dynam was significantly less palatable, with significantly less consumption of treated feed compared with either Equipalazone Powder or Danilon Equidos. The...
Pharmacokinetics and in vitro effects of tegaserod, a serotonin 5-hydroxytryptamine 4 (5-HT4) receptor agonist with prokinetic activity in horses. Tegaserod, a serotonin agonist, has been shown to have prokinetic effects in horses, but pharmacokinetic information is not currently available. The pharmacokinetics and in vitro effects of tegaserod were evaluated. Tegaserod increased the contractile activity of smooth muscle preparations of the equine pelvic flexure. Pertinent pharmacokinetic parameters for a single IV and oral dose were determined. Therapeutic plasma concentrations of tegaserod were achieved by a single oral dose at 0.27 mg/kg. These findings indicate that further clinical studies are warranted to investigate potential bene...
Safety of elevated dosages of a 0.24% diflubenzuron pellet administered orally to horses. The safety of a feed-thru pellet formulation containing the insect growth regulator diflubenzuron (0.24%) for control of manure-breeding flies (Musca domestica L. and Stomoxys calcitrans L.) in horses was evaluated. Pellets were administered orally at 0, 1, 3, and 5 times the clinical dosage (0.12 to 0.20 mg/kg) on a daily basis for 31 consecutive days. Variables examined included daily clinical observations, hematology, coagulation, serum chemistry, acetylcholinesterase inhibition, body weights, and physical examinations. Horses remained healthy throughout the study, and no adverse reactions ...
Effect of hyperimmune plasma on the severity of pneumonia caused by Rhodococcus equi in experimentally infected foals. This study evaluated the prophylactic effectiveness of hyperimmune plasma (HIP) as an aid in the prevention of pneumonia caused by experimental infection with Rhodococcus equi. Thirty neonatal foals were administered R. equi HIP or saline at 2 days of age and were infected with virulent R. equi at 7 days. All foals developed signs or symptoms of respiratory disease. Radiographic scores on day 28 and neutrophil concentrations on day 49 were significantly greater in control foals, and time to respiratory effort score of 2 or higher was significantly shorter for control foals. Three foals, all in...
Enrofloxacin use in a long-distance transport model of equine respiratory disease. Successful clinical management of bacterial pneumonia in horses depends on the administration of an appropriate antimicrobial agent at an adequate dosage and frequency, given by the correct route of administration for an adequate duration. Empiric antimicrobial therapy should be based on the clinician's experience and current veterinary literature. Based on the frequency of Gram-positive bacterial pathogens isolated from horses with bacterial pneumonia, every effort should be made to provide antimicrobial coverage for this class of pathogens. Gram-negative pathogens may co-exist; therefore, br...
A comparison of N-butylscopolammonium and lidocaine for control of rectal pressure in horses. In its FDA approved formulation, N-butylscopolammonium bromide (Buscopan Injectable Solution, Boehringer Ingelheim Vetmedica) is an anticholinergic spasmolytic agent indicated for management of abdominal pain associated with spasmodic colic, flatulent colic, and simple impactions in horses. Use of this drug ablates gastrointestinal peristalsis and rectal pressure. It ahs been suggested that N-butylscopolammonium bromide could be used to facilitate rectal examinations in horses. This study compared the effects of N-butylscopolammonium bromide versus lidocaine and a saline control on rectal pres...
Evaluation of the efficacy provided by a Recombinant Canarypox-Vectored Equine West Nile Virus vaccine against an experimental West Nile Virus intrathecal challenge in horses. Efficacy of the Recombitek Equine West Nile Virus (WNV) vaccine was evaluated against a WNV intrathecal challenge model that results in WNV-induced clinical disease. Ten vaccinated (twice at days 0 and 35) and 10 control horses were challenged 2 weeks after administration of the second vaccine with a virulent WNV by intrathecal administration. After the challenge, eight of 10 controls developed clinical signs of encephalomyelitis whereas one vaccinate exhibited muscle fasciculation only once. Nine controls and one vaccinate developed a fever. Histopathology revealed mild to moderate nonsuppura...
Clonidine in horses: identification, detection, and clinical pharmacology. Clonidine is classified as a class 3 performance-enhancing agent by the Association of Racing Commissioners International and thus has the potential to influence the outcome of a race. In this study, the authors developed and validated a sensitive gas chromatograph and mass spectrometer method to determine the pharmacokinetic parameters of clonidine in equine plasma samples after IV administration of a single dose (0.025 mg/kg) of clonidine in horses. At this dose, clonidine produced rapid and profound sedation, which cold be quickly reversed with yohimbine. Clonidine was able to produce an an...
Modulation of leptin, insulin, and growth hormone in obese pony mares under chronic nutritional restriction and supplementation with ractopamine hydrochloride. Horses fed beyond their nutritional requirement and that are physically inactive will develop obesity, which is often accompanied by insulin resistance and heightened risk of laminitis. The use of pharmacologic agents in combination with nutritional restriction may promote weight loss in obese horses unable to exercise because of laminitic pain. This study shows that reducing feed intake of brome grass hay to 75% of ad libitum intake in obese pony mares reduces body weight without induced exercise. Additional supplementation of ractopamine hydrochloride for 6 weeks resulted in a tendency for i...
New therapeutic approaches for equine protozoal myeloencephalitis: pharmacokinetics of diclazuril sodium salts in horses. Diclazuril is a triazine-based antiprotozoal agent which may have clinical application in the treatment of equine protozoal myeloencephalomyelitis (EPM). In this study, the use of the sodium salt diclazuril to increase the apparent bioavailability of diclazuril for the treatment and prophylaxis of EPM and various other Apicomplexan mediated diseases is described. In this study, diclazuril sodium salt was synthesized and administered to horses as diclazuril sodium salt formulations. The absorption, distribution, and clearance of diclazuril sodium salt in the horse are described. Diclazuril was ...
Target animal safety and tolerance study of pyrantel pamoate paste (19.13% w/w pyrantel base) administered orally to horses. Pyrantel pamoate paste (19.13% w/w pyrantel base) for the treatment of tapeworm, Anoplocephala spp was evaluated for target animal safety and tolerance in horses treated orally at 0, 1, 3, 5, and 10 times the clinical dose of 13.2 mg pyrantel base/kg body weight administered daily for six consecutive days. Parameters evaluated included clinical signs, food and water consumption, body weights, physical examinations, clinical pathology (hematology, coagulation, serum chemistry, urinalyses, and fecal examinations), complete necropsy, organ weights, and histopathology. No adverse events or test ar...
Scintigraphic, radiographic, and thermographic appearance of the metacarpal and metatarsal regions of adult healthy horses treated with nonfocused extracorporeal shock wave therapy–a pilot study. Nonfocused extracorporeal shock wave therapy (ESWT) treatment protocol is commonly used in veterinary practice. This study investigated the effects of four nonfocused ESWT treatments, given 2 weeks apart, on bone radiopharmaceutical uptake and radiographic and thermographic appearance in the metacarpal and metatarsal regions in six adult untrained horses. There were no measurable treatment effects determined by thermography (daily), scintigraphy (at 2-week intervals), and radiography (before study initiation and at study completion) between treated and control limbs. It was concluded that no g...
Urinary and serum concentrations of diclofenac after topical application to horses. The liposomal cream formulation of diclofenac, an NSAID, is an effective, safe, and convenient way to treat localized areas of inflammation in horses. The results of this study reveal urinary and serum concentrations of diclofenac following topical administration of 1% liposomal diclofenac cream for 10 days at the labeled dose and at 2X and 4X the labeled dose. These results demonstrate the slow absorption and elimination of 1% liposomal diclofenac cream and may be useful when estimating the withdrawal time needed before a competition in order to prevent an inadvertent positive drug test.
In vivo pretreatment with PGG-glucan fails to alter cytokine mRNA expression of equine peripheral blood mononuclear cells exposed to endotoxin ex vivo. Twelve healthy horses were assigned to treatment or control groups. Treated horses received PGG-Glucan[ED-1] (1 mg/kg, IV) 24 hours prior to peripheral blood mononuclear cell (PBMC) isolation. PBMCs were isolated and incubated in the presence of lipopolysachharide (LPS). At 0, 6, 12, 24 and 48 hours messenger RNA (mRNA) was extracted. Reverse transcription polymerase chain reaction (PCR) was performed and cytokine mRNA expression for tumor necrosis factor alpha (TNFalpha), interleukin 1beta (IL-1beta), interleukin 10 (IL-10) and interferon gamma (IFN-gamma) determined using real time PCR. A si...
The anamnestic serologic response to vaccination with a canarypox virus-vectored recombinant West Nile virus (WNV) vaccine in horses previously vaccinated with an inactivated WNV vaccine. A new recombinant West Nile virus (WNV) vaccine has been licensed for use in horses. Prior to the availability of the recombinant vaccine in 2004, the only equine WNV vaccine available on the market had been an inactivated vaccine. Since the recombinant vaccine only expresses selected viral genes, the question could be posed as to whether a single dose of the recombinant vaccine would be effective in producing an anamnestic serologic response in horses previously vaccinated with an inactivated WNV vaccine. In this study we demonstrate that vaccination of horses with a canarypox-vectored recomb...
Double-blinded placebo-controlled clinical field trial to evaluate the safety and efficacy of topically applied 1% diclofenac liposomal cream for the relief of lameness in horses. A topical 1% diclofenac liposomal cream proved to be safe, easy to use, and effective in reducing equine lameness caused by degenerative joint disease. Diclofenac liposomal cream was shown to reduce lameness as graded by owners and veterinarians, regardless of the severity or chronicity of the clinical condition. Topical application allowed for more convenient administration than oral or injectable agents, and no clinically relevant hematologic or serum biochemical changes were noted. The liposomal cream provided a delivery system for diclofenac, an NSAID, to achieve therapeutic levels locally...
Antiparasitic activity of an ivermectin and praziquantel combination paste in horses. Modern anthelmintic use in horses has decreased the prevalence of the large strongyles, which has in turn shifted the focus of parasitologists to the pathogenic importance of the small strongyles, tapeworms, and other parasites. These studies show that a combination product containing ivermectin and praziquantel allowed efficacious treatment of horses for nematode, cestode, and bot infections. The use of this combination product may be of special benefit to horses that are mainly kept outdoors and on grazing pastures.
Pharmacokinetics, stability, and retrospective analysis of use of an oral gel formulation of the bovine injectable enrofloxacin in horses. In many cases of equine infectious disease, long-term administration of antimicrobial drugs is required. Oral agents are preferred because of the relative ease of administration compared with other routes. Enrofloxacin has been shown to be effective against a variety of equine pathogens, but oral administration of this drug has proved difficult in horses. An oral gel formulation made from the injectable cattle product produces blood levels sufficient to resolve infections caused by a variety of common equine pathogens.
Evaluation of immune responses in horses immunized using a killed Sarcocystis neurona vaccine. Clinically normal horses developed cellular immunity to Sarcocystis neurona following IM vaccination with a commercial killed S. neurona vaccine, as indicated by the development of measurable anti-S. neurona IgG antibodies and additional intradermal skin testing. Large-scale independent assessments of the vaccine's performance and safety are in progress under field conditions. The next step in the evaluation of this vaccine would be to attempt experimental challenge after a reproducible reliable equine model of S. neurona encephalitis has been established that allows for reisolation of the pat...
Serologic responses to eastern and western equine encephalomyelitis vaccination in previously vaccinated horses. A prospective study was performed to determine the serologic response of previously vaccinated horses to revaccination against eastern and western equine encephalomyelitis (EEE and WEE). Horses responded variably to each antigen, and some horses had low or undetectable antibodies 6 months after vaccination. Some horses did not develop increasing titers to EEE or WEE despite recent vaccination. Geometric mean titers peaked 2 weeks after revaccination and were significantly increased from before revaccination. Except for one horse, EEE:WEE titer ratios ranged from 0.25 to 2.0. Regular vaccinatio...
The mare reproductive loss syndrome and the eastern tent caterpillar: a toxicokinetic/statistical analysis with clinical, epidemiologic, and mechanistic implications. During 2001, central Kentucky experienced acute transient epidemics of early and late fetal losses, pericarditis, and unilateral endophthalmitis, collectively referred to as mare reproductive loss syndrome (MRLS). A toxicokinetic/statistical analysis of experimental and field MRLS data was conducted using accelerated failure time (AFT) analysis of abortions following administration of Eastern tent caterpillars (ETCs; 100 or 50 g/day or 100 g of irradiated caterpillars/day) to late-term pregnant mares. In addition, 2001 late-term fetal loss field data were used in the analysis. Experimental dat...
Field evaluation of moxidectin/praziquantel oral gel in horses. The safety and efficacy of 2% moxidectin/12.5% praziquantel oral gel administered at a rate of 0.4 mg moxidectin and 2.5 mg praziquantel/kg was studied in client-owned horses under field use conditions. Four hundred horses (300 treated with moxidectin/praziquantel oral gel and 100 treated with vehicle) were enrolled, feces were collected, and eggs were counted. Investigators as well as horse owners were masked to treatment assignment. No adverse reactions to treatment were observed in any horses. Moxidectin/praziquantel gel reduced Anoplocephala spp by more than 99% and provided a significant ...
Effect of furosemide on urine specific gravity and osmolality in thoroughbred racehorses. Postrace urine samples from thoroughbred horses were examined to compare osmolality and specific gravity between horses treated with furosemide and those not treated. Samples were assigned to groups in relation to reported medication (furosemide) status, race finish position, and distance of race. Urine osmolality was significantly (P <.05) lower in samples from horses treated with furosemide when compared with untreated horses. Specific gravity determinations are less precise at measuring urine osmolality at lower levels (1.01 g/ml or less). The measurement of osmolality is a superior meth...