OBJECTIVE To evaluate adherence of methicillin-resistant Staphylococcus pseudintermedius (MRSP) to 5 suture materials commonly used in small animal surgery. SAMPLE 10 epidemiologically unrelated MRSP isolates (obtained from dogs with clinical infections) that had strong biofilm-forming ability and 5 types of suture. PROCEDURES The 5 types of suture evaluated were monofilament polyglecaprone 25, monofilament polydioxanone, triclosan-coated (TC)–monofilament polydioxanone, braided polyglactin 910, and barbed monofilament polydioxanone. Suture segments were incubated in standard suspensions of MRSP for 2 minutes. Segments were then placed in tryptone soy broth and incubated overnight. After incubation, segments were rinsed with PBS solution and sonicated to dislodge adherent bacteria. Resulting suspensions were used to create serial dilutions that were plated, incubated overnight, and counted the following day. Bacterial adherence to 1 segment of each suture type was assessed by use of scanning electron microscopy. RESULTS There was significantly less adherence of MSRP to TC–monofilament polydioxanone than to polyglecaprone 25, polyglactin 910, barbed monofilament polydioxanone, and monofilament polydioxanone. There was significantly less adherence of MSRP to polyglecaprone than to polyglactin 910. CONCLUSIONS AND CLINICAL RELEVANCE Barbed suture had a bacterial adherence profile comparable to that for monofilament suture. Adherence of MRSP was greatest for braided polyglactin 910. Use of TC–monofilament polydioxanone can be considered for patients that are at high risk of developing surgical site infections and for which a surgeon chooses a multifilament suture.

The only way to diagnose hepatic fibrosis in dogs is by histological assessment of a liver biopsy specimen. As this technique is invasive and susceptible to sampling variation, serum biomarkers are used to detect hepatic fibrosis in humans. The objective of this study was to assess the utility of hyaluronic acid (HA), procollagen type III N-terminal peptide (PIIINP), and tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) as serum markers of canine hepatic fibrosis. Serum samples were collected from 47 dogs with histologically confirmed hepatobiliary disease and 24 healthy dogs in order to measure concentrations of HA, PIIINP, and TIMP-1. Hepatic fibrosis was staged using a 5-point scoring scheme. There was no correlation between serum concentrations of HA or PIIINP and the severity of hepatic fibrosis. There was a negative correlation between serum concentration of TIMP-1 and the severity of hepatic fibrosis (r s = −0.33; P = 0.036). It was not possible to use serum concentrations of HA, PIIINP, or TIMP-1 to discriminate between dogs with absent-to-moderate hepatic fibrosis and those with marked-to-very-marked fibrosis. The results of this study do not support the utility of measuring serum concentrations of HA, PIIINP, or TIMP-1 for diagnosing canine hepatic fibrosis. Further studies are needed to support this finding.

OBJECTIVE To evaluate the effect of IM administration of a tiletamine hydrochloride–zolazepam hydrochloride (TZ) combination with either dexmedetomidine hydrochloride or saline (0.9% NaCl) solution (SS) on the motor response to claw clamping, selected cardiorespiratory variables, and quality of recovery from anesthesia in alpacas. ANIMALS 5 adult sexually intact male alpacas. PROCEDURES Each alpaca was given the TZ combination (2 mg/kg) with dexmedetomidine (5 [D5], 10 [D10], 15 [D15], or 20 [D20] µg/kg) or SS IM at 1-week intervals (5 experiments); motor response to claw clamping was assessed, and characteristics of anesthesia, recovery from anesthesia, and selected cardiorespiratory variables were recorded. RESULTS Mean ± SEM duration of lack of motor response to claw clamping was longest when alpacas received treatments D15 (30.9 ± 5.9 minutes) and D20 (40.8 ± 5.9 minutes). Duration of lateral recumbency was significantly longer with dexmedetomidine administration. The longest time (81.3 ± 10.4 minutes) to standing was observed when alpacas received treatment D20. Following treatment SS, 4 alpacas moved in response to claw clamping at the 5-minute time point. Heart rate decreased from pretreatment values in all alpacas when dexmedetomidine was administered. Treatments D10, D15, and D20 decreased Pao2, compared with treatment SS, during the first 15 minutes. During recovery, muscle stiffness and multiple efforts to regain a sternal position were observed in 3 SS-treated and 1 D5-treated alpacas; all other recoveries were graded as excellent. CONCLUSIONS AND CLINICAL RELEVANCE In TZ-anesthetized alpacas, dexmedetomidine (10, 15, and 20 µg/kg) administered IM increased the duration of lack of motor response to claw clamping, compared with the effect of SS.

OBJECTIVE To determine the minimum infectious dose of porcine epidemic diarrhea virus (PEDV) in virus-inoculated feed. ANIMALS 30 crossbred 10-day-old pigs. PROCEDURES Tissue culture PEDV was diluted to form 8 serial 10-fold dilutions. An aliquot of stock virus (5.6 × 105 TCID50/mL) and each serial PEDV dilution were mixed into 4.5-kg batches of feed to create 9 PEDV-inoculated feed doses; 1 virus-negative dose of culture medium in feed was also created. Pigs were challenge exposed via oral administration of PEDV-inoculated feed, and fecal swab specimens were collected. All pigs were euthanized 7 days after challenge exposure; fresh tissues were collected and used for PCR assay, histologic examination, and immunohistochemical analysis. RESULTS The PCR cycle threshold (Ct) decreased by approximately 10 when PEDV was added to feed, compared with results for equivalent PEDV diluted in tissue culture medium. Pigs became infected with PEDV when challenge exposed with the 4 highest concentrations (lowest concentration to cause infection, 5.6 × 10(1) TCID50/g; Ct = 27 in tissue culture medium and 37 in feed). CONCLUSIONS AND CLINICAL RELEVANCE In this study, PEDV in feed with detectable Ct values of 27 to 37 was infective. The Ct was 37 for the lowest infective PEDV dose in feed, which may be above the limit of detection established for PEDV PCR assays used by some diagnostic laboratories. Overall, results indicated 5.6 × 10(1) TCID50/g was the minimum PEDV dose in feed that can lead to infection in 10-day-old pigs under the conditions of this study.

OBJECTIVE To define a frailty-related phenotype—a clinical syndrome associated with the aging process in humans—in aged dogs and to investigate its association with time to death. ANIMALS 116 aged guide dogs. PROCEDURES Dogs underwent a clinical geriatric assessment (CGA) and were followed to either time of death or the study cutoff date. A 5-component clinical definition of a frailty phenotype was derived from clinical items included in a geriatric health evaluation scoresheet completed by veterinarians during the CGA. Univariate (via Kaplan-Meier curves) and multivariate (via Cox proportional hazards models) survival analyses were used to investigate associations of the 5 CGA components with time to death. RESULTS 76 dogs died, and the median time from CGA to death was 4.4 years. Independent of age at the time of CGA, dogs that had ≥ 2 of the 5 components (n = 10) were more likely to die during the follow-up period, compared with those that had 1 or no components (adjusted hazard ratio, 3.9 [95% confidence interval, 1.4 to 10.9]). After further adjustments for subclinical or clinical diseases and routine biomarkers, the adjusted hazard ratio remained significant. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that signs of frailty appeared to be a risk factor for death in dogs. The concept of frailty in dogs requires further development. IMPACT FOR HUMAN MEDICINE The concept of frailty, as defined for humans, seems transposable to dogs. Given that they share humans' environments and develop several age-related diseases similar to those in humans, dogs may be useful for the study of environmental or age-related risk factors for frailty in humans.

OBJECTIVE To investigate in vitro carboplatin release from 6 carrier media. SAMPLE 6 carboplatin-containing carrier media. PROCEDURES An in vitro release study was performed with 6 commercially available carrier media: a hemostatic gelatin sponge, a poloxamer copolymer gel, and 2 sizes (3 and 4.8 mm in diameter) of beads molded from each of 2 commercial calcium sulfate products. All carrier media contained 10 mg of carboplatin. Carrier media specimens were placed in 37°C PBS solution for 96 hours. Carboplatin concentrations in PBS solution were measured by use of high-performance liquid chromatography at 15 time points to calculate the amount and proportion of carboplatin released from each specimen. RESULTS Peak release of carboplatin from the poloxamer copolymer gel and hemostatic gelatin sponge were achieved after 4 and 20 hours, respectively. Maximum release did not differ significantly between the poloxamer copolymer gel and hemostatic gelatin sponge, but both released significantly more carboplatin within 96 hours than did both of the commercial calcium sulfate products. The poloxamer copolymer gel released 99% of the carboplatin, and the hemostatic gelatin sponge released 68.5% of the carboplatin. Peak release of carboplatin from the calcium sulfate beads was not reached within 96 hours. CONCLUSIONS AND CLINICAL RELEVANCE In this study, carboplatin release from the hemostatic gelatin sponge was incomplete. The poloxamer copolymer gel and hemostatic gelatin sponge released carboplatin rapidly in vitro, whereas calcium sulfate beads did not.

OBJECTIVE To characterize polymorphisms of the gene for cytochrome P450 isozyme 2D50 (CYP2D50) and the disposition of 2 CYP2D50 probe drugs, dextromethorphan and debrisoquine, in horses. ANIMALS 23 healthy horses (22 Thoroughbreds and 1 Standardbred). PROCEDURES Single-nucleotide polymorphisms (SNPs) in CYP2D50 were identified. Disposition of dextromethorphan (2 mg/kg) and debrisoquine (0.2 mg/kg) were determined after oral (dextromethorphan) or nasogastric (debrisoquine) administration to the horses. Metabolic ratios of plasma dextromethorphan and total dextrorphan (dextrorphan plus dextrorphan-O-β-glucuronide) and 4-hydroxydebrisoquine concentrations were calculated on the basis of the area under the plasma concentration-versus-time curve extrapolated to infinity for the parent drug divided by that for the corresponding metabolite. Pharmacokinetic data were used to categorize horses into the phenotypic drug-metabolism categories poor, extensive, and ultrarapid. Disposition patterns were compared among categories, and relationships between SNPs and metabolism categories were explored. RESULTS Gene sequencing identified 51 SNPs, including 27 nonsynonymous SNPs. Debrisoquine was minimally detected after oral administration. Disposition of dextromethorphan varied markedly among horses. Metabolic ratios for dextromethorphan ranged from 0.03 to 0.46 (mean, 0.12). On the basis of these data, 1 horse was characterized as a poor metabolizer, 18 were characterized as extensive metabolizers, and 3 were characterized as ultrarapid metabolizers. CONCLUSIONS AND CLINICAL RELEVANCE Findings suggested that CYP2D50 is polymorphic and that the disposition of the probe drug varies markedly in horses. The polymorphisms may be related to rates of drug metabolism. Additional research involving more horses of various breeds is needed to fully explore the functional implication of polymorphisms in CYP2D50.

OBJECTIVE To investigate the role of the major equine acute phase protein serum amyloid A (SAA) in inflammation of equine intraarticular tissues. SAMPLE Articular chondrocytes and fibroblast-like synoviocytes (FLSs) from 8 horses (4 horses/cell type). PROCEDURES Chondrocytes and FLSs were stimulated in vitro for various periods up to 48 hours with cytokines (recombinant interleukin [IL]-1β, IL-6, tumor necrosis factor-α, or a combination of all 3 [IIT]) or with recombinant SAA. Gene expression of SAA, IL-6, matrix metalloproteinases (MMP)-1 and −3, and cartilage-derived retinoic acid-sensitive protein were assessed by quantitative real-time PCR assay; SAA protein was evaluated by immunoturbidimetry and denaturing isoelectric focusing and western blotting. RESULTS All cytokine stimulation protocols increased expression of SAA mRNA and resulted in detectable SAA protein production in chondrocytes and FLSs. Isoforms of SAA in lysed chondrocytes and their culture medium corresponded to those previously detected in synovial fluid from horses with joint disease. When exposed to SAA, chondrocytes and FLSs had increased expression of IL-6, SAA, and MMP3, and chondrocytes had increased expression of MMP-1. Chondrocytes had decreased expression of cartilage-derived retinoic acid-sensitive protein. CONCLUSIONS AND CLINICAL RELEVANCE Upregulation of SAA in chondrocytes and FLSs stimulated with proinflammatory cytokines and the proinflammatory effects of SAA suggested that SAA may be involved in key aspects of pathogenesis of the joint inflammation in horses.

OBJECTIVE To compare regional proportions and spatial distributions of volumetric bone mineral density (BMDv) of the palmar aspect of the distal epiphysis of the third metacarpal bone (McIII) in limbs with or without a condylar fracture from Thoroughbred racehorses. SAMPLE McIIIs from cadavers of Thoroughbred racehorses with (n = 6 bones) and without (8) a condylar fracture. PROCEDURES BMDv and spatial distributions of BMDv in peripheral quantitative CT images of the distal epiphysis of McIIIs were quantitatively assessed with spatial analysis software. Relative proportions of voxels within 9 threshold categories of BMDv and spatial statistics for BMDv distribution were compared between fractured and nonfractured limbs. RESULTS No significant differences in BMDv characteristics were identified between fractured and nonfractured limbs, although fractured limbs had a lower proportion of voxels in the BMDv thresholds 700 to < 800 mg/cm3 and 800 to < 900 mg/cm3 but a higher proportion of voxels in the BMDv threshold 1,000 to < 1,100 mg/cm3 for the central condylar region of the medial condyle. Results of spatial analysis reflected the response of bone to race training rather than differences between fractured and nonfractured limbs. In both limb groups, uniform clusters of low BMDv with areas of high BMDv were identified. CONCLUSIONS AND CLINICAL RELEVANCE BMDv characteristics of the distal epiphysis of McIII reflected training load, and fracture characteristics were subtle. Serial imaging techniques in conjunction with detailed training data are required to elucidate the onset of the pathological response to load in horses.

The diagnosis of bovine genital campylobacteriosis (BGC) presents significant challenges, as traditional methods lack sensitivity when prolonged transport of samples is required. Assays of preputial samples by means of real-time polymerase chain reaction (PCR) provide good sensitivity and high throughput capabilities. However, there is limited information on the acceptable duration of transport and temperature during transport of samples. In addition, the use of pooled samples has proven to be a valuable strategy for the diagnosis of other venereal diseases in cattle. The objectives of the present study were to determine the effect of sample pooling and of transport time and temperature on the clinical sensitivity of a real-time quantitative PCR (qPCR) assay for Campylobacter fetus subsp. venerealis in preputial samples from beef bulls. Eight infected bulls and 176 virgin yearling bulls were used as the source of samples. The qPCR sensitivity was comparable for unpooled samples and pools of 5 samples, whereas sensitivity was decreased for pools of 10 samples. Sensitivity for the various pool sizes improved with repeated sampling. For shorter-term transport (2 and 48 h), sensitivity was greatest when the samples were stored at 4°C and 30°C, whereas for longer-term transport (96 h) sensitivity was greatest when the samples were stored at −20°C. The creation of pools of 5 samples is therefore a good option to decrease costs when screening bulls for BGC with the qPCR assay of direct preputial samples. Ideally the samples should be stored at 4°C and arrive at the laboratory within 48 h of collection, but when that is not possible freezing at −20°C could minimize the loss of sensitivity.