Objective--To develop a simple extractionless method for detection of rosiglitazone in canine plasma and test the method in a pharmacokinetic study after oral administration of rosiglitazone in dogs. Animals--3 client-owned dogs with cancer. Procedures--High-performance liquid chromatography-tandem mass spectrometry was performed on canine plasma. The 3 dogs with cancer in the pharmacokinetic study were assessed via physical examination and clinicopathologic evaluation and considered otherwise healthy. Food was withheld for 12 hours, and dogs were administered a single dose (4 mg/m2) of rosiglitazone. Plasma was collected at various times, processed, and analyzed for rosiglitazone. Results--The developed method was robust and detected a minimum of 0.3 ng of rosiglitazone/mL. Mean ± SD maximum plasma concentration was 205.2 ± 79.1 ng/mL, which occurred at 3 ± 1 hours, and mean ± SD elimination half-life was 1.4 ± 0.4 hours. The area under the plasma rosiglitazone concentration-versus-time curve varied widely among the 3 dogs (mean ± SD, 652.2 ± 351.3 ng/h/mL). Conclusions and Clinical Relevance--A simple extractionless method for detection of rosiglitazone in canine plasma was developed and was validated with excellent sensitivity, accuracy, precision, and recovery. The method enabled unambiguous evaluation and quantitation of rosiglitazone in canine plasma. This method will be useful for pharmacokinetic, bioavailability, or drug-drug interaction studies. Oral rosiglitazone administration was well tolerated in the dogs.

Objective--To test the hypotheses that preparation method, exposure to shear force, and exposure to collagen affect the release of growth factors from equine platelet-rich plasma (PRP). Sample Population--PRP obtained from 6 horses. Procedures--PRP was prepared via 2 preparation methods (tube and automated) and subjected to 6 treatment conditions (resting, detergent, exposure to shear via 21- and 25-gauge needles, and exposure to collagen [10 and 20 μg/mL]). Concentrations of platelet-derived growth factor, isoform BB (PDGF-BB); transforming growth factor β, isoform 1 (TGFβ1); and insulin-like growth factor, isoform 1 (IGF-1) were quantified by use of ELISAs. Statistical analysis was conducted via repeated-measures ANOVA. Results--Platelet numbers were significantly higher in tube-prepared PRP than in automated-prepared PRP Growth factor concentrations did not differ significantly between preparation methods. Mean PDGF-BB concentration ranged from 134 to 7,157 pg/mL, mean TGFβ1 concentration ranged from 1,153 to 22,677 pg/mL, and mean IGF-1 concentration ranged from 150 to 280 ng/mL. Shear force did not affect growth factor concentrations. Dose-dependent increases in PDGF-BB and TGFβ1 were detected in response to collagen, but equalled only 10% of the estimated total platelet content. Concentrations of IGF-1 were not significantly different among treatments and negative or positive control treatments. Serum concentrations of PDGF-BB and TGFβ1 exceeded concentrations in PRP for most treatment conditions. Conclusions and Clinical Relevance--Release of growth factors from equine PRP was negligible as a result of the injection process alone. Investigation of platelet-activation protocols is warranted to potentially enhance PRP treatment efficacy in horses.

Objective-To compare inhibitory effects of topically applied 1% prednisolone acetate suspension, 0.03% flurbiprofen solution, 0.1% dexamethasone suspension, and 0.1% diclofenac solution on paracentesis-induced blood-aqueous barrier breakdown in cats. Animals-9 healthy cats. Procedures-Paracentesis of the anterior chamber was performed in both eyes of each cat. One eye of each cat was treated with a topically administered anti-inflammatory medication (1% prednisolone [n = 7 cats], 0.03% flurbiprofen [7], 0.1% dexamethasone [9], or 0.1% diclofenac [8]) immediately following paracentesis and at 6, 10, and 24 hours after paracentesis. The contralateral untreated eye served as the control eye. Each cat had a 6-day washout period between experimental drugs. Breakdown of the blood-aqueous barrier was quantified by use of laser flaremetry. Results-Topical administration of 1% prednisolone significantly reduced aqueous humor flare at 4, 8, and 26 hours after paracentesis. Topical administration of 0.1% diclofenac significantly reduced aqueous humor flare at 8 and 26 hours after paracentesis. Topical administration of 0.1% dexamethasone and 0.03% flurbiprofen did not significantly decrease flare at any time point. There were significant differences in intraocular pressures between NSAID-treated eyes and untreated contralateral eyes. Conclusions and Clinical Relevance-Topical administration of 1% prednisolone and 0.1% diclofenac significantly reduced intraocular inflammation in cats with paracentesis-induced uveitis. Topical administration of 1% prednisolone or 0.1% diclofenac may be appropriate choices when treating cats with anterior uveitis. Topical administration of diclofenac and flurbiprofen should be used with caution in cats with a history of ocular hypertension.

Objective-To compare efficacy of 2 commercial ovine Campylobacter vaccines and an experimental bacterin in guinea pigs following IP inoculation with Campylobacter jejuni IA3902. Animals-51 female guinea pigs. Procedures-Pregnant and nonpregnant animals were randomly assigned to 1 of 4 treatment groups and administered a commercial Campylobacter vaccine labeled for prevention of campylobacteriosis in sheep via two 5-mL doses 14 days apart (vaccine A; n = 13), another labeled for prevention of campylobacteriosis via two 2-mL doses (vaccine B; 12), an experimental bacterin prepared from the challenge strain (12), or a sham vaccine (14). Ten days later, animals were challenged IP with C jejuni IA3902; 48 hours later, animals were euthanized, complete necropsy was performed, and blood and tissue samples were obtained for bacteriologic culture. Results-Administration of vaccine B or the experimental bacterin, but not vaccine A, significantly reduced 48-hour infection rates versus administration of the sham vaccine. A significantly reduced 48-hour infection rate was associated with administration of vaccine B independent of pregnancy status. Conclusions and Clinical Relevance-Administration of vaccine B significantly reduced infection in guinea pigs challenged with C jejuni IA3902, similar to a homologous bacterin. Results suggested that vaccine B or an autogenous product may be effective in controlling ovine campylobacteriosis caused by this emergent abortifacient strain. Bacteriologic culture of blood, liver, bile, and uterus in nonpregnant guinea pigs 48 hours after inoculation may be a useful screening tool for comparing efficacy of C jejuni vaccines.

Glanzmann thrombasthenia (GT) is characterized by a defect of platelet aggregation. This autosomal recessive genetic disorder is caused by an abnormality of the platelet glycoprotein receptors alpha IIb or beta III. Recently, we identified a horse with clinical and pathological features of GT. The aim of this study was to describe this case of GT at the molecular level. A point mutation from G to C in exon 2 of ITGA2B causing a substitution of the expected amino acid arginine 72 (Arg72) by a proline (Pro72) was encountered. This amino acid change may result in abnormal structural conformations that yield an inactive alpha IIb subunit. The genomic DNA analysis showed that this horse was homozygous for the missense mutation.

Objective—To evaluate changes in the cortical bone of the proximal phalanx of the fore-limbs of Thoroughbreds in response to training. Animals—Twenty-seven 2-year-old Thoroughbreds (20 females, 2 males, and 5 geldings). Procedures—Horses were principally in training for races in a straight line and in a clockwise direction. Lateromedial and dorsopalmar radiographic views of each metacarpophalangeal joint were obtained before the horses started training and 1 year after starting exercise and racing. Width of the dorsal, palmar, lateral, and medial cortex and the width and thickness of the medulla were measured. Ratios (rather than absolute values) were used to remove the effect of differences in bone size among horses. Results—10 horses were lost from the study. Radiographs were obtained for 17 horses 1 year after starting training (9 horses raced in a clockwise direction, and 8 raced in clockwise and counterclockwise directions). There was no difference between the cortical bone in the right and left forelimbs at the start of the study. After training for 1 year, the palmar cortex in the right forelimb was significantly thicker than that in the left forelimb. Conclusions and Clinical Relevance—The strain patterns, biomechanics of rapid exercise, and type of training most probably determined differences in the adaptive responses of the proximal phalanx. The data reported here can be used in the evaluation of weight-bearing distribution along the proximal phalanx and evaluation of the relationship between exercise and bone remodelling of the proximal phalanx.

Objective: To evaluate the effect of several sedation protocols on glomerular filtration rate (GFR) in cats as measured by use of quantitative renal scintigraphy and to analyze interobserver differences in GFR calculation. Animals: 5 cats (1 sexually intact male, 1 neutered male, and 3 sexually intact females). Procedures: Effects on GFR of 3 sedation protocols commonly used at the Iowa State University College of Veterinary Medicine were evaluated. The protocols were medetomidine (11 μg/kg) and butorphanol tartrate (0.22 mg/kg) administered IM; ketamine hydrochloride (10 mg/kg) and midazolam (0.5 mg/kg) administered IV; and ketamine (10 mg/kg), midazolam (0.5 mg/kg), and acepromazine maleate (0.05 mg/kg) administered IM. Results for the 3 protocols were compared with results of GFR measurements obtained in these same cats without sedation (control protocol). Results: No significant difference between GFR measurements was associated with the 3 sedation protocols, compared with GFR measurements for the control protocol. The greatest mean GFR values were for the medetomidine-butorphanol and ketamine-midazolam protocols. There were no significant differences between observers for calculation of GFR. Conclusions and Clinical Relevance: Results suggested that none of the 3 sedation protocols had significant effects on GFR calculated by use of quantitative renal scintigraphy, compared with results for GFR evaluations performed in the cats when they were not sedated. No significant interobserver error was evident. However, the statistical power of this study was low, and the probability of a type II error was high.

The objective of this study was to develop a model using equine data from geographically limited surveillance locations to predict risk categories for West Nile virus (WNV) infection in horses in all geographic locations across the province of Saskatchewan. The province was divided geographically into low-, medium-, or high-risk categories for WNV, based on available serology information from 923 horses obtained through 4 studies of WNV infection in horse populations in Saskatchewan. Discriminant analysis was used to build models using the observed risk of WNV in horses and geographic division-specific environmental data as well as to predict the risk category for all areas, including those beyond the surveillance zones. High-risk areas were indicated by relatively lower rainfall, higher temperatures, and a lower percentage of area covered in trees, water, and wetland. These conditions were most often identified in the southwest corner of the province. Environmental conditions can be used to identify those areas that are at highest risk for WNV. Public health managers could use prediction maps, which are based on animal or human information and developed from annual early season meteorological information, to guide ongoing decisions about when and where to focus intervention strategies for WNV.

Objective—To assess agreement between anesthetic agent concentrations measured by use of an infrared anesthetic gas monitor (IAGM) and refractometry. Sample—4 IAGMs of the same type and 1 refractometer. Procedures—Mixtures of oxygen and isoflurane, sevoflurane, desflurane, or N2O were used. Agent volume percent was measured simultaneously with 4 IAGMs and a refractometer at the common gas outlet. Measurements obtained with each of the 4 IAGMs were compared with the corresponding refractometer measurements via the Bland-Altman method. Similarly, Bland-Altman plots were also created with either IAGM or refractometer measurements and desflurane vaporizer dial settings. Results—Bias ± 2 SD for comparisons of IAGM and refractometer measurements was as follows: isoflurane, −0.03 ± 0.18 volume percent; sevoflurane, −0.19 ± 0.23 volume percent; desflurane, 0.43 ± 1.22 volume percent; and N2O, −0.21 ± 1.88 volume percent. Bland-Altman plots comparing IAGM and refractometer measurements revealed nonlinear relationships for sevoflurane, desflurane, and N2O. Desflurane measurements were notably affected; bias ± limits of agreement (2 SD) were small (0.1 ± 0.22 volume percent) at < 12 volume percent, but both bias and limits of agreement increased at higher concentrations. Because IAGM measurements did not but refractometer measurements did agree with the desflurane vaporizer dial settings, infrared measurement technology was a suspected cause of the nonlinear relationships. Conclusions and Clinical Relevance—Given that the assumption of linearity is a cornerstone of anesthetic monitor calibration, this assumption should be confirmed before anesthetic monitors are used in experiments.

This study investigated the occurrence and antimicrobial resistance profiles of Escherichia coli and Salmonella sp. isolated from swine samples submitted to the Minnesota Veterinary Diagnostic Laboratory (MVDL) in Saint Paul, Minnesota from 1995 to 2004. During this time period, a total of 5072 E. coli and 2793 Salmonella sp. was isolated. Most of these isolates were found to be resistant to the tetracycline and beta-lactam group of antibiotics. Resistance to spectinomycin was also frequently observed. An increasing trend in ampicillin resistance and a decreasing trend in apramycin resistance were seen in both pathogens, although ampicillin resistance was relatively higher in E. coli than in Salmonella. Aminoglycoside (amikacin) and quinolone (enrofloxacin) were the only antimicrobials to which minimum or no resistance was observed. The resistance of pig pathogens to several antibiotics indicates the need to routinely monitor the use of these antimicrobials and their associated resistance in pig populations.