Hemorrhagic pneumonia in mink is a fatal disease caused by Pseudomonas aeruginosa. Very little is known about P. aeruginosa in relation to genotype and the mechanisms underlying antimicrobial resistance in mink. A total of 110 P. aeruginosa samples were collected from mink from Chinese mink farms between 2007 and 2015. Samples underwent molecular genotyping using pulsed-field gel electrophoresis (PFGE) and multi-locus sequence typing (MLST), antimicrobial susceptibility and its mechanism were investigated at the molecular level. The PFGE identified 73 unique types and 15 clusters, while MLST identified 43 (7 new) sequence types (ST) and 12 sequence type clonal complexes (STCC). Sequence types and PFGE showed persistence of endemic clones in cities Wendeng (Shandong, China) and Dalian (Liaoning, China), even in different timelines. The MLST also revealed the gene correlation of the mink P. aeruginosa across different time and place. The ST1058 (n = 14), ST882 (n = 11), and ST2442 (n = 10) were the predominant types, among which ST1058 was the only one found both in Shandong province and Dalian (Liaoning, China). The MLST for P. aeruginosa infection in mink was highly associated with that in humans and other animals, implying possible transmission events. A small proportion of mink exhibited drug resistance to P. aeruginosa (9/69, 13%) with resistance predominantly to fluoroquinolone, aminoglycoside, and β-lactamase. Eight strains had mutations in the quinolone-resistance determining regions (QRDR). High proportions (65%; 72/110) of the fosA gene and 2 types of glpt deletion for fosmycin were detected. Furthermore, in the whole genome sequence of one multidrug resistant strain, we identified 27 genes that conferred resistance to 14 types of drugs.

OBJECTIVE To evaluate the elastic modulus of various ligaments of the forelimbs of cadaveric horses. SAMPLE 408 ligaments from 37 forelimbs of 10 Thoroughbred cadavers and cadavers of 9 other horse breeds. PROCEDURES Collateral ligaments and straight and oblique sesamoid ligaments were harvested from the proximal interphalangeal, metacarpophalangeal, carpal, and elbow joints of both forelimbs of all 19 horses. Ligament dimensions were measured, and the elastic modulus was determined by tensile testing the ligaments with a strain rate of 1 mm•s(-1). RESULTS Elastic modulus of the ligaments differed significantly among joints. Highest mean ± SE elastic modulus was for the medial collateral ligament of the metacarpophalangeal joints of Thoroughbreds (68.3 ± 11.0 MPa), and the lowest was for the lateral collateral ligament of the elbow joints of other breeds (2.8 ± 0.3 MPa). Thoroughbreds had a significantly higher elastic modulus for the collateral ligaments of the proximal interphalangeal and metacarpophalangeal joints, compared with values for the other breeds. There was large variation in elastic modulus. Elastic modulus was negatively affected by age. In the ligaments in the distal aspect of the forelimbs, elastic modulus was negatively affected by height at the highest point of the shoulders (ie, withers). CONCLUSIONS AND CLINICAL RELEVANCE Cross-sectional area and elastic modulus of collateral ligaments in the forelimbs of equine cadavers differed between breeds and among joints, which may have been reflective of their relative physiologic function under loading during exercise.

OBJECTIVE To evaluate the effect of contrast medium injection rate on CT-derived renal perfusion estimates obtained with the maximum slope method in healthy small dogs. ANIMALS 6 healthy sexually intact male purpose-bred Beagles. PROCEDURES All dogs underwent CT perfusion analysis 3 times in a crossover design, receiving a different contrast medium injection rate (1.5, 3.0, and 4.5 mL/s) each time, with a 1-week interval between imaging sessions. All CT images were obtained at the level of the left renal hilus. The time to peak aortic enhancement (TPAE) and time to initial renal venous enhancement (TIRVE) were measured from time-attenuation curves. The renal CT perfusion estimates (blood flow and blood volume) were estimated by use of the maximum slope method, which assumes no venous outflow of contrast medium during CT perfusion analysis. RESULTS The TPAE occurred at or before the TIRVE at all injection rates. Median values of estimated blood flow and blood volume did not differ significantly among injection rates. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that the assumption of no venous outflow of contrast medium during renal CT perfusion analysis with the maximum slope method was satisfied for all 3 contrast medium injection rates in the evaluated dogs. A low injection rate may be more practical than higher injection rates that require large catheters for CT perfusion analysis in small dogs such as Beagles.

OBJECTIVE To determine the pharmacokinetics and adverse effects of maropitant citrate after IV and SC administration to New Zealand White rabbits (Oryctolagus cuniculus). ANIMALS 11 sexually intact (3 males and 8 females) adult rabbits. PROCEDURES Each rabbit received maropitant citrate (1 mg/kg) IV or SC. Blood samples were collected at 9 (SC) or 10 (IV) time points over 48 hours. After a 2-week washout period, rabbits received maropitant by the alternate administration route. Pharmacokinetic parameters were calculated. Body weight, food and water consumption, injection site, mentation, and urine and fecal output were monitored. RESULTS Mean ± SD maximum concentration after SC administration was 14.4 ± 10.9 ng/mL and was detected at 1.25 ± 0.89 hours. Terminal half-life after IV and SC administration was 10.4 ± 1.6 hours and 13.1 ± 2.44 hours, respectively. Bioavailability after SC administration was 58.9 ± 13.3%. Plasma concentration at 24 hours was 2.87 ± 1.69 ng/mL after IV administration and 3.4 ± 1.2 ng/mL after SC administration. Four rabbits developed local dermal reactions at the injection site after SC injection. Increased fecal production was detected on the day of treatment and 1 day after treatment. CONCLUSIONS AND CLINICAL RELEVANCE Plasma concentrations of rabbits 24 hours after SC and IV administration of maropitant citrate (1 mg/kg) were similar to those of dogs at 24 hours. Reactions at the SC injection site were the most common adverse effect detected. Increased fecal output may suggest an effect on gastrointestinal motility. Additional pharmacodynamic and multidose studies are needed.

OBJECTIVE To evaluate repeatability and reproducibility of muscle condition score (MCS) in dogs with various degrees of muscle loss; to compare MCS, muscle ultrasonographic measurements, and quantitative magnetic resonance (QMR) measurements; and to identify cutoff values for ultrasonographic measurements of muscle that can be used to identify dogs with cachexia and sarcopenia. ANIMALS 40 dogs of various age, body condition score (BCS), and MCS. PROCEDURES A prospective cross-sectional study was conducted. Body weight, BCS, QMR measurements, thoracic radiographic measurements, and muscle ultrasonographic measurements were assessed once in each dog. The MCS for each dog was assessed 3 separate times by 4 separate raters. RESULTS For the MCS, overall κ for interrater agreement was 0.50 and overall κ for intrarater agreement ranged from 0.59 to 0.77. For both interrater and intrarater agreement, κ coefficients were higher for dogs with normal muscle mass and severe muscle loss and lower for dogs with mild and moderate muscle loss. The MCS was significantly correlated with age (r = −0.62), vertebral epaxial muscle score (VEMS; r = 0.71), forelimb epaxial muscle score (FLEMS; r = 0.58), and BCS (r = 0.73), and VEMS was significantly correlated (r = 0.84) with FLEMS. Cutoff values for identification of mild muscle loss determined by use of VEMS and FLEMS were 1.124 and 1.666, respectively. CONCLUSIONS AND CLINICAL RELEVANCE MCS had substantial repeatability and moderate reproducibility for assessment of muscle mass in dogs. Prospective studies of MCS, VEMS, and FLEMS for assessment of muscle mass in dogs are warranted.

OBJECTIVE To compare the effects of a dexmedetomidine-ketamine-midazolam (DKM) anesthetic protocol versus isoflurane inhalation anesthesia on echocardiographic variables and plasma cardiac troponin 1 (cTnI) concentration in black-tailed prairie dogs (BTPDs; Cynomys ludovicianus). ANIMALS Nine 6-month-old sexually intact male captive BTPDs. PROCEDURES Each BTPD was randomly assigned to be anesthetized by IM administration of dexmedetomidine (0.25 mg/kg), ketamine (40 mg/kg), and midazolam (1.5 mg/kg) or via inhalation of isoflurane and oxygen. Three days later, each BTPD underwent the alternative anesthetic protocol. Echocardiographic data and a blood sample were collected within 5 minutes after initiation and just prior to cessation of each 45-minute-long anesthetic episode. RESULTS Time or anesthetic protocol had no significant effect on echocardiographic variables. For either protocol, plasma cTnI concentration did not differ with time. When administered as the first treatment, neither anesthetic protocol significantly affected plasma cTnI concentration. However, with regard to findings for the second treatments, plasma cTnI concentrations in isoflurane-treated BTPDs (n = 4; data for 1 animal were not analyzed because of procedural problems) were higher than values in DKM-treated BTPDs (4), which was suspected to be a carryover effect from prior DKM treatment. CONCLUSIONS AND CLINICAL RELEVANCE The DKM and isoflurane anesthetic protocols did not have any significant effect on echocardiographic measurements in the BTPDs. Increases in plasma cTnI concentration during the second anesthetic episode were evident when BTPDs underwent the DKM anesthetic protocol as the first of the 2 treatments, suggestive of potential myocardial injury associated with that anesthetic protocol. Clinicians should consider these findings, especially when evaluating BTPDs with known or suspected cardiac disease.

OBJECTIVE To develop and validate a sandwich ELISA for the measurement of α1-proteinase inhibitor (α1-PI) concentrations in serum and fecal samples obtained from common marmosets (Callithrix jacchus). SAMPLE Leftover serum (n = 42) and fecal (23) samples submitted for diagnostic testing; paired serum and fecal samples obtained from 30 common marmosets at 2 research colonies. PROCEDURES A sandwich ELISA was developed and analytically validated by determining the lower limit of detection, linearity, accuracy, precision, and reproducibility. Reference intervals for α1-PI concentrations in serum and feces of common marmosets were calculated. RESULTS The standard curve was generated for concentrations between 1 and 100 ng/mL. Mean ± SD observed-to-expected ratio for serial dilutions of serum and fecal samples was 117.1 ± 5.6% (range, 112.2% to 123.0%) and 106.1 ± 19.7% (range, 82.6% to 130.2%), respectively. Mean observed-to-expected ratio for spiking recovery of serum and fecal samples was 102.9 ± 12.1% (range, 86.8% to 115.8%) and 97.9 ± 19.0% (range, 83.0% to 125.1%), respectively. Reference interval for serum concentrations of α1-PI was 1,254 to 1,813 μg/mL, for 3-day mean fecal concentrations was 11.5 to 42.2 μg/g of feces, and for 3-day maximum fecal concentrations was 13.2 to 51.2 μg/g of feces. CONCLUSIONS AND CLINICAL RELEVANCE The ELISA was linear, accurate, precise, and reproducible for quantification of α1-PI concentrations in serum and feces of common marmosets. However, the ELISA had limited linearity and accuracy for spiking recovery of fecal samples.

OBJECTIVE: To determine the pharmacokinetics of a single oral dose of trazodone and its effect on the activity of domestic pigeons (Columba livia). ANIMALS: 6 healthy adult male domestic pigeons. PROCEDURES: During the first of 3 experiments, birds received orally administered trazodone at doses ranging from 3 to 30 mg/kg to determine the dose for subsequent experiments. During the second experiment, each bird received 1 dose of trazodone (30 mg/kg, PO). Blood was collected for determination of plasma trazodone concentration before and at predetermined times for 24 hours after drug administration. Pharmacokinetic parameters were calculated by noncompartmental analysis. During experiment 3, birds were instrumented with ultralightweight accelerometers and received orally administered trazodone (30 mg/kg) or an equal volume of water twice at a 48-hour interval. Activity of birds was monitored for 24 hours after administration of each treatment. RESULTS: No adverse effects were observed. Mean ± SD terminal half-life of trazodone was 5.65 ± 1.75 hours. Plasma trazodone concentrations remained > 0.130 μg/mL for approximately 20 hours. Trazodone did not affect the activity of birds during the first 2 and 15 hours after administration. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that oral administration of 1 dose (30 mg/kg) of trazodone to healthy pigeons was safe and resulted in plasma drug concentrations that were similar to those considered therapeutic in humans and dogs for up to 20 hours. Further research is necessary to characterize the pharmacokinetics for repeated doses as well as the clinical effects of trazodone in birds with behavior problems.

OBJECTIVE To characterize abdominal lymphatic drainage in cats after thoracic duct ligation (TDL) and cisterna chyli ablation (CCA). ANIMALS 7 purpose-bred research cats. PROCEDURES Baseline CT lymphangiography was performed. A popliteal lymph node was injected with iohexol, and images were acquired at 5-minute intervals for 15 minutes. Cats underwent TDL and CCA; methylene blue was used to aid in identifying lymphatic vessels. The CT lymphangiography was repeated immediately after and 30 days after surgery. All cats were euthanized and necropsied. RESULTS Results of baseline CT lymphangiography were unremarkable for all 7 cats. Only 5 cats completed the study. Leakage of contrast medium at the level of the cisterna chyli was seen on CT lymphangiography images obtained from all cats immediately after surgery. Evaluation of 30-day postoperative CT lymphangiography images revealed small branches entering the caudal vena cava in 2 cats, leakage of contrast medium into the caudal vena cava with no visible branches in 1 cat, and no contrast medium in the caudal vena cava in 2 cats. Contrast medium did not flow beyond the level of the cisterna chyli in any cat. Gross examination during necropsy revealed that all cats had small lymphatic vessels that appeared to connect to local vasculature identified in the region of the cisterna chyli. CONCLUSIONS AND CLINICAL RELEVANCE Abdominal lymphaticovenous anastomoses formed after TDL and CCA in cats. This would support use of these procedures for treatment of cats with idiopathic chylothorax, although additional studies with clinically affected cats are warranted.

Septic arthritis is an important disease in horses, necessitating aggressive and prolonged therapy. In order to guide therapy, reliable methods of detecting the eradication of infection are needed. Therefore, the objective of this study was to investigate detection of eradication of infection in an experimental model of equine septic arthritis using standard diagnostic techniques. For this purpose, 17 adult horses were assigned to 3 experimental groups. The middle carpal joint of each horse was injected with Escherichia coli (Septic group, n = 8), lipopolysaccharide (LPS) (LPS group, n = 6), or sterile saline (Control group, n = 3) at day 0. Contralateral joints were not injected. Standard therapy was applied to all joints except non-injected joints in the Control group at day 1. Sequential samples of synovial fluid (SF) were collected for bacterial culture using 3 culture media [Columbia blood agar (CBA), brain heart infusion broth (BHI), and Signal blood culture medium] and for cytological evaluation [percentage neutrophils (PN), total nucleated cell count (TNCC), and total protein (TP)]. Escherichia coli-specific polymerase chain reaction (PCR) was carried out to detect E. coli DNA in synovial fluid. Culture and PCR were positive for E. coli in all joints injected with E. coli at day 1 and 1 joint was positive on BHI at day 4. Based on the results of bacterial culture, PCR, and TNCC, the elimination of infection in our experimental model occurred by day 4 post-infection in 6 out of 7 cases. Total protein (TP) and PN remained elevated at clinical threshold used for diagnosis of septic arthritis until day 14. In our experimental model of E. coli-induced arthritis, we conclude that TP and PN may not be good indicators for detecting the eradication of bacterial infection caused by E. coli from infected and subsequently treated joints.