Nix Pro Color Sensor provides comparable color measurements to HunterLab colorimeter for fresh beef.

The HunterLab MiniScan (HunterLab) colorimeter is used in meat quality research worldwide for measuring meat color; however, the Nix Pro Color Sensor (Nix) could be a less expensive alternative that is easier to operate. Therefore, the objective of this study was to compare the two colorimeters to objectively evaluate fresh beef color. Longissimus thoracis muscle from one side of A maturity beef carcasses (n = 200) was evaluated using both the HunterLab (3 technical replicate scans) and Nix (3, 5, 7, and 9 technical replicate scans) colorimeters. The correlation between the HunterLab and Nix for L* (lightness), a* (redness), and b* (yellowness) values ranged between r = 0.80 to 0.85 and the Bland Altman Limits of Agreement analysis indicated good agreement between the Nix and HunterLab colorimeters for all the color parameters. These results indicated that the Nix colorimeter could be a viable alternative for HunterLab colorimeters.

Evaluation of acupuncture for the treatment of pain associated with naturally-occurring osteoarthritis in dogs: a prospective, randomized, placebo-controlled, blinded clinical trial.

BACKGROUND: Acupuncture has been used as a treatment for pain associated with osteoarthritis (OA) for thousands of years; however, there is a lack of definitive evidence for this indication in humans or animals. The aim of this study was to prospectively evaluate the efficacy of acupuncture on lameness and clinical function in dogs affected by naturally-occurring OA using objective outcome measures. A total of 32 client-owned dogs completed this prospective, randomized, placebo-controlled, blinded clinical trial, using a cross-over design. Participants were assigned to receive placebo or acupuncture treatment once weekly for 4 weeks in random order with a two-week wash-out period in between treatment phases. Outcome measures included ground reaction forces (GRF), subjective orthopedic scoring (SOS), activity counts (AC), and owner-completed clinical metrology instruments (CMI; Canine Brief Pain Inventory [CBPI] and Client Specific Outcome Measures [CSOM]). For statistical comparison, baseline GRF, SOS, and CMI data were compared to data obtained 1 week after each treatment phase. Similarly, total weekly AC of the final week of each treatment phase were compared to the baseline week. RESULTS: Evidence of differences between baseline versus acupuncture and placebo treatments was not identified for the following outcome measures: GRF, AC, or SOS. However, evidence of differences was identified for some of the CMI scores, including the CSOM questionnaire which showed evidence of improvement when comparing baseline versus acupuncture (p = 0.0002) as well as between placebo versus acupuncture treatments (p = 0.035) but not between baseline versus placebo treatments (p = 0.221). CONCLUSIONS: The applied acupuncture protocol did not show improvement in function when using objective outcome measures for OA in dogs; however, certain CMI measurements recorded some degree of treatment response.

Surgically induced astigmatism in canines following sutured dorsonasal vs dorsotemporal clear corneal incisions.

OBJECTIVES: To investigate use of the Pentacam® HR for evaluation of surgically induced corneal astigmatism (SIA) in canines undergoing bilateral phacoemulsification and determine differences between dorsonasal and dorsotemporal clear corneal incisions. ANIMALS: Client-owned canines undergoing bilateral phacoemulsification. PROCEDURES: Patients received anterior segment imaging pre-operatively, immediately post-operatively, and 2-4 months post-operatively (follow-up). Total corneal refractive power was used to determine SIA. Surgically induced astigmatism was compared between right and left eyes, representing dorsotemporal and dorsonasal incisions, respectively. Repeated measures analyses were used between time points and paired t test compared SIA between eyes. RESULTS: Complete imaging series were obtained for seven patients. Follow-up imaging occurred at a median of 112 days (range 60-132 days) post-operatively. For repeated measures analyses, significant differences were found between pre- and immediate post-operative values (P < 0.01), and between immediate post-operative and follow-up values (P < 0.01). There was no significant difference between pre-operative and follow-up values. Surgically induced astigmatism was significantly different between right and left eyes, with values of 2.01 ± 1.24 D and 3.05 ± 1.58 D at 3 mm radius (P < 0.05), and 2.04 ± 1.18 D and 3.06 ± 1.27 D at 4 mm radius (P < 0.05) for dorsotemporal and dorsonasal incisions, respectively. CONCLUSIONS: Preliminary investigation revealed improvement of corneal SIA 2-4 months post-operatively, but development of significantly more SIA in dorsonasal vs dorsotemporal incisions. This prompts consideration of patient or microscope rotation to create a more dorsotemporal incision when possible.

Anterior segment parameters in normal dogs using the Pentacam® HR Scheimpflug system.

OBJECTIVE: To describe and compare normative anterior segment parameters between canine age groups using the Pentacam® HR Scheimpflug camera (Pentacam). ANIMALS STUDIED: Thirty-six sedated dogs (60 eyes) of varying ages and breeds were imaged with the Pentacam; only nondiseased anterior segments were included. PROCEDURES: Dogs were divided into three age groups: Group 1 (1-5 years), Group 2 (6-10 years), and Group 3 (11-15 years). Values assessed included central corneal thickness (CCT), anterior and posterior corneal elevation (ACE/PCE), anterior and posterior corneal curvature metrics, corneal volume (CV), anterior and posterior corneal astigmatism (AA/PA), anterior chamber depth (ACD), anterior chamber volume (ACV), and anterior chamber angle (ACA). Tukey-adjusted pairwise comparisons were performed. RESULTS: Overall CCT (mean ± SD) was 631.07 ± 59.91 µm. Central corneal thickness was 608.60 ± 48.63 µm for Group 1, 648.57 ± 51.06 µm for Group 2, and 635.37 ± 73.71 µm for Group 3. Anterior corneal elevation (ACE) measured 9.08 ± 0.58 mm, PCE measured 8.04 ± 0.50 mm, and CV was 58.13 ± 5.39 mm3 . Astigmatism values were 1.34 ± 0.94 D for AA and 0.46 ± 0.44 D for PA. Anterior chamber values were 3.76 ± 0.56 mm for ACD, 383.68 ± 66.24 mm3 for ACV, and 23.62 ± 29.33˚ for ACA. Significant differences were found between Groups 1 and 2 for CV (55.08 ± 4.08 mm3 and 60.32 ± 4.19 mm3 , respectively), (P = 0.02). CONCLUSIONS: Corneal volume significantly increased between Group 1 and Group 2. Central corneal thickness increased from Group 1 to Group 3, but was not significant with the current sample size. There were no other differences between age groups.

Canine central corneal thickness measurements via Pentacam-HR® , optical coherence tomography (Optovue iVue® ), and high-resolution ultrasound biomicroscopy.

OBJECTIVE: To compare central corneal thickness (CCT) values in canine eyes using Pentacam-HR® Scheimpflug imaging (Pentacam), Optovue® iVue spectral-domain optical coherence tomography (SD-OCT), and high-resolution ultrasound biomicroscopy (UBM) and generate normative canine Pentacam CCT values. ANIMALS STUDIED: Twenty-four client-owned dogs (37 eyes) with nondiseased cornea(s) presenting to the Colorado State University Veterinary Teaching Hospital. PROCEDURES: Corneal images were acquired via Pentacam, SD-OCT, and UBM in the listed order. Machine-calculated values of CCT from Pentacam and SD-OCT were compared to operator-measured values from UBM. Bland-Altman analysis was performed to evaluate agreement between instruments. RESULTS: Mean CCT ± SD measured by Pentacam was 629.73 ± 64.57 µm, by SD-OCT was 610.56 ± 57.48 µm, and by UBM was 689.77 ± 55.93 µm. On average, Pentacam CCT was 19.17 ± 32.90 µm (3%) thicker than SD-OCT and 65.12 ± 44.52 µm (10.3%) thinner than UBM. SD-OCT was on average 82.47 µm (13.5% ) thinner than UBM. The 95% limits of agreement were (-45.31, 83.65), (-152.38, 22.13), and (-126.674, -38.270) for Pentacam vs. SD-OCT, Pentacam vs. UBM, and SD-OCT vs. UBM respectively. All differences were statistically significant (P < 0.01). CONCLUSIONS: Considering there is an average of 7.5% normal diurnal variation in canine CCT, a 3.0% difference between Pentacam and SD-OCT values is likely not clinically relevant. However, Pentacam measurements were both statistically and clinically significantly different from UBM and SD-OCT measurements.

Effects of constant rate infusions of dexmedetomidine or MK-467 on the minimum alveolar concentration of sevoflurane in dogs.

OBJECTIVE: To determine the effects of low and high dose infusions of dexmedetomidine and a peripheral α2-adrenoceptor antagonist, MK-467, on sevoflurane minimum alveolar concentration (MAC) in dogs. STUDY DESIGN: Crossover experimental study. ANIMALS: Six healthy, adult Beagle dogs weighing 12.6±0.9 kg (mean±standard deviation). METHODS: Dogs were anesthetized with sevoflurane in oxygen. After a 60-minute instrumentation and equilibration period, the MAC of sevoflurane was determined in triplicate using the tail clamp technique. PaCO2 and temperature were maintained at 40±5 mmHg (5.3±0.7 kPa) and 38±0.5 ºC, respectively. After baseline MAC determination, dogs were administered two incremental loading and infusion doses of either dexmedetomidine (1.5 µg kg-1 then 1.5 µg kg-1 hour-1 and 4.5 µg kg-1 then 4.5 µg kg-1 hour-1) or MK-467 (90 µg kg-1 then 90 µg kg-1 hour-1 and 180 µg kg-1 then 180 µg kg-1 hour-1); loading doses were administered over 10 minutes. MAC was redetermined in duplicate starting 30 minutes after the start of drug administration at each dose. End-tidal sevoflurane concentrations were corrected for calibration and adjusted to sea level. A repeated-measures analysis was performed and comparisons between doses were conducted using Tukey's method. Statistical significance was considered at p<0.05. RESULTS: Sevoflurane MAC decreased significantly from 1.86±0.3% to 1.04±0.1% and 0.57±0.1% with incremental doses of dexmedetomidine. Sevoflurane MAC significantly increased with high dose MK-467, from 1.93±0.3% to 2.29±0.5%. CONCLUSIONS AND CLINICAL RELEVANCE: Dexmedetomidine caused a dose-dependent decrease in sevoflurane MAC, whereas MK-467 caused an increase in MAC at the higher infusion dose. Further studies evaluating the combined effects of dexmedetomidine and MK-467 on MAC and cardiovascular function may elucidate potential benefits of the addition of a peripheral α2-adrenergic antagonist to inhalation anesthesia in dogs.

Intra- and interspecies gene expression models for predicting drug response in canine osteosarcoma.

BACKGROUND: Genomics-based predictors of drug response have the potential to improve outcomes associated with cancer therapy. Osteosarcoma (OS), the most common primary bone cancer in dogs, is commonly treated with adjuvant doxorubicin or carboplatin following amputation of the affected limb. We evaluated the use of gene-expression based models built in an intra- or interspecies manner to predict chemosensitivity and treatment outcome in canine OS. Models were built and evaluated using microarray gene expression and drug sensitivity data from human and canine cancer cell lines, and canine OS tumor datasets. The "COXEN" method was utilized to filter gene signatures between human and dog datasets based on strong co-expression patterns. Models were built using linear discriminant analysis via the misclassification penalized posterior algorithm. RESULTS: The best doxorubicin model involved genes identified in human lines that were co-expressed and trained on canine OS tumor data, which accurately predicted clinical outcome in 73 % of dogs (p = 0.0262, binomial). The best carboplatin model utilized canine lines for gene identification and model training, with canine OS tumor data for co-expression. Dogs whose treatment matched our predictions had significantly better clinical outcomes than those that didn't (p = 0.0006, Log Rank), and this predictor significantly associated with longer disease free intervals in a Cox multivariate analysis (hazard ratio = 0.3102, p = 0.0124). CONCLUSIONS: Our data show that intra- and interspecies gene expression models can successfully predict response in canine OS, which may improve outcome in dogs and serve as pre-clinical validation for similar methods in human cancer research.

Comparison between Pentacam-HR and optical coherence tomographycentral corneal thickness measurements in healthy feline eyes.

OBJECTIVES: To measure the central corneal thickness (CCT) in healthy feline eyes with Scheimpflug imaging (Pentacam, Pentacam(®) -HR) and to compare these values with those obtained with spectral-domain optical coherence tomography (OCT, Optovue(®) iVue). ANIMALS STUDIED: Thirty one sedated Domestic Short-haired cats. PROCEDURES: Two repeated CCT measurements were obtained from both eyes using Pentacam measured at the pupil center and corneal apex (CCTpupil and CCTapex ) and using SD-OCT (CCTOCT ). Agreement between the imaging modalities for CCT and intradevice repeatability was evaluated with Bland-Altman analysis. Mixed modeling was used to test for a difference between methods. RESULTS: The calculated mean ± SD CCT was CCTOCT  = 584.93 ± 39.05 µm, CCTpupil  = 608.25 ± 47.26 µm, and CCTapex  = 606.41 ± 44.18 µm. There was a statistically significant difference between CCTOCT vs. CCTpupil (P < 0.0007) and CCTOCT vs. CCTapex (P < 0.0003) (n = 59 eyes). The 95% limits of agreement (LoA) for CCTOCT vs. CCTpupil was (-89.57 µm, 40.04 µm) and for CCTOCT vs. CCTapex was (-79.62 µm, 33.79 µm) (n = 59 eyes). 95% LoA between repeated CCT measurements by SD-OCT was (-10.23 µm, 9.32 µm) and by Pentacam was (-22.66 µm, 18.30 µm) at pupil and (-15.81 µm, 16.17 µm) at corneal apex (n = 11 eyes). CONCLUSIONS: SD-OCT and Pentacam provide excellent CCT measurement repeatability. Pentacamapex is our recommended clinical setting for use of the Pentacam. The level of agreement between SD-OCT and Pentacam for CCT is good.

Development of a metabolic biosignature for detection of early Lyme disease.

BACKGROUND: Early Lyme disease patients often present to the clinic prior to developing a detectable antibody response to Borrelia burgdorferi, the etiologic agent. Thus, existing 2-tier serology-based assays yield low sensitivities (29%-40%) for early infection. The lack of an accurate laboratory test for early Lyme disease contributes to misconceptions about diagnosis and treatment, and underscores the need for new diagnostic approaches. METHODS: Retrospective serum samples from patients with early Lyme disease, other diseases, and healthy controls were analyzed for small molecule metabolites by liquid chromatography-mass spectrometry (LC-MS). A metabolomics data workflow was applied to select a biosignature for classifying early Lyme disease and non-Lyme disease patients. A statistical model of the biosignature was trained using the patients' LC-MS data, and subsequently applied as an experimental diagnostic tool with LC-MS data from additional patient sera. The accuracy of this method was compared with standard 2-tier serology. RESULTS: Metabolic biosignature development selected 95 molecular features that distinguished early Lyme disease patients from healthy controls. Statistical modeling reduced the biosignature to 44 molecular features, and correctly classified early Lyme disease patients and healthy controls with a sensitivity of 88% (84%-95%), and a specificity of 95% (90%-100%). Importantly, the metabolic biosignature correctly classified 77%-95% of the of serology negative Lyme disease patients. CONCLUSIONS: The data provide proof-of-concept that metabolic profiling for early Lyme disease can achieve significantly greater (P < .0001) diagnostic sensitivity than current 2-tier serology, while retaining high specificity.

A metabolic biosignature of early response to anti-tuberculosis treatment.

BACKGROUND: The successful treatment of tuberculosis (TB) requires long-term multidrug chemotherapy. Clinical trials to evaluate new drugs and regimens for TB treatment are protracted due to the slow clearance of Mycobacterium tuberculosis (Mtb) infection and the lack of early biomarkers to predict treatment outcome. Advancements in the field of metabolomics make it possible to identify metabolic profiles that correlate with disease states or successful chemotherapy. However, proof-of-concept of this approach has not been provided for a TB-early treatment response biosignature (TB-ETRB). METHODS: Urine samples collected at baseline and during treatment from 48 Ugandan and 39 South African HIV-seronegative adults with pulmonary TB were divided into discovery and qualification sets, normalized to creatinine concentration, and analyzed by liquid chromatography-mass spectrometry to identify small molecule molecular features (MFs) in individual patient samples. A biosignature that distinguished baseline and 1 month treatment samples was selected by pairwise t-test using data from two discovery sample sets. Hierarchical clustering and repeated measures analysis were applied to additional sample data to down select molecular features that behaved consistently between the two clinical sites and these were evaluated by logistic regression analysis. RESULTS: Analysis of discovery samples identified 45 MFs that significantly changed in abundance at one month of treatment. Down selection using an extended set of discovery samples and qualification samples confirmed 23 MFs that consistently changed in abundance between baseline and 1, 2 and 6 months of therapy, with 12 MFs achieving statistical significance (p < 0.05). Six MFs classified the baseline and 1 month samples with an error rate of 11.8%. CONCLUSIONS: These results define a urine based TB-early treatment response biosignature (TB-ETRB) applicable to different parts of Africa, and provide proof-of-concept for further evaluation of this technology in monitoring clinical responses to TB therapy.

Tissue oxygen saturation is positively correlated with oxygen delivery and cardiac output in a canine hemorrhagic shock and resuscitation model.

OBJECTIVE: To determine if tissue oxygen saturation (StO2) correlates with oxygen delivery (DO2) and/or cardiac output (CO) in a canine hemorrhagic shock model. ANIMALS: 8 healthy purpose-bred dogs. METHODS: Dogs were anesthetized, and hemorrhagic shock was induced by withdrawing up to 60% of total blood volume, targeting a mean arterial pressure (MAP) of 40 mm Hg. The withdrawn blood was returned to the patient in 2 equal aliquots. Data was collected at 4 time points: 10 minutes after MAP was stabilized under anesthesia (time point [TP]-1), 10 minutes after up to 60% of blood volume was removed to target a MAP of 40 mm Hg (TP2), 10 minutes after the return of 50% of shed blood (TP3), and 10 minutes after the return of the remaining 50% of shed blood (TP4). Total blood volume withdrawn, StO2, CO, heart rate, and MAP were recorded, and DO2 was calculated at each TP. RESULTS: Mean StO2 significantly decreased between TP1 (77.8% [± 9.54]) and TP2 (44.8% [± 19.5]; P < .001 vs TP1). Mean StO2 increased to 63.1% (± 9.85) at TP3, but remained significantly lower compared to TP1 (P = .002). There was no difference between mean StO2 at TP4 (82.5% [± 12.6]) versus TP1 (P = .466). StO2 has a strong, positive correlation to both CO (r = 0.80; P < .001) and DO2 (r = 0.75; P < .001). CLINICAL RELEVANCE: A decrease in StO2 may be used in conjunction with physical examination findings and diagnostic parameters to support a diagnosis of shock. The return of shed blood was correlated with increases in StO2, DO2, and CO, suggesting that StO2 may be used as a marker of adequate resuscitation.

An analysis of the influence of preslaughter management factors on welfare and meat quality outcomes in fed beef cattle in the United States.

During the preslaughter phase, cattle are transported from their place of origin to a slaughter facility, experiencing transportation, lairage, environmental factors, and novel environments. Although research exists that has focused how the preslaughter phase impacts cattle welfare and meat quality, some significant preslaughter management factors and subsequent welfare and meat quality outcomes have not been thoroughly explored. The objective of this study was to assess the effects of preslaughter management factors on welfare and meat quality outcomes in fed beef cattle in the United States. Transportation factors, environmental characteristics, lairage factors, cattle characteristics, and several meat quality variables were collected from 5 federally inspected commercial processing facilities in the United States. After excluding slaughter lots that included <75% complete datasets, a total of 619 slaughter lots representing 84,508 head of cattle were used for further analysis. Predictor variables of interest included processing plant, cattle breed, sex class, operation shift at the plant, distance traveled to the plant, truck waiting time to unload at the plant, lairage duration and space allowance, temperature humidity index, and windspeed. Outcome variables of interest included cattle mobility, carcass bruising, dark cutting (DC), quality grades, and hot carcass weights. Logistic and linear regressions were used to analyze the associations between the predictor and outcome variables of interest. Increased distance traveled and truck waiting time were associated with higher odds of mobility impairment (P = 0.0009 and P = 0.007, respectively), with each 10 km increase in distance traveled having an odds ratio (OR) of 1.001 (95% confidence interval [CI]: 1.000 to 1.001) and each 1-min increase in waiting time having an OR of 1.003 (CI: 1.001 to 1.004). Conversely, a 10-km increase in distance traveled decreased the odds of carcass bruising (OR: 0.997, CI: 0.996 to 0.998; P < 0.0001). Longer lairage was associated with increased odds of DC (P = 0.0415), with each 60-min increase in duration having an OR of 1.034 (CI: 1.001 to 1.068). The results demonstrate the importance of truck arrival management (i.e., scheduling, prioritizing unloading) on mobility. Focusing on lairage management (i.e., density and time) may provide some opportunities to improve meat quality.

Benchmarking current preslaughter management factors, welfare indicators, and meat quality outcomes at commercial fed cattle processing facilities in the United States.

Preslaughter management factors and their impacts on cattle welfare and meat quality are well documented in current literature. However, certain management factors related to transportation and lairage are underrepresented. Benchmarking preslaughter management factors that can impact welfare and meat quality outcomes will allow the industry to identify areas for improvement. The objective of the current study was to benchmark preslaughter management factors for a nationwide sample of commercial fed cattle processing facilities. Five processing facilities in the West, Midwest, and Southwest regions of the United States were sampled from March 2021 to July 2022. Data were collected on a total of n = 637 slaughter lots representing n = 87,220 head of cattle. Variables of interest included general cattle characteristics, distance traveled to the plant, truck wait times to unload, environmental conditions, lairage density, and lairage duration. Additionally, mobility was scored using a four-point locomotion scale (one being normal, not lame, and four being extremely reluctant to move). Carcasses were also observed for bruising using the following scale: no bruises, bruises smaller or larger than a deck of cards, and having multiple bruises. Descriptive statistics were performed on the data at the lot and individual animal level. On average, cattle traveled 155.8 ±â€…209.6 km (mean ±â€…SD) from the feedlot to the processing facility and waited 30.3 ±â€…39.7 min to unload. Once in lairage pens, cattle were held for 200.7 ±â€…195.0 min. The mean lairage stocking density was 3.1 ±â€…2.0 m2 per head. A majority of the cattle scored a mobility score of 1 (n = 77,645, 91.8%), 7.8% (n = 6,125) were scored as a two and the remaining less than one percent of cattle were scored as either a 3 or 4 (n = 265). Carcasses with bruises less than or equal to the size of a deck of cards (n = 22,672, 27.1%) were less frequent than bruises measuring greater than the size of a deck of cards (n = 34,427, 42.6%). Of carcasses that were bruised, 65.2% (n = 39,856) had multiple bruises of varying size. This baseline data on preslaughter management factors identifies opportunities for improvement in wait times, lairage densities, and factors that cause bruising. Future studies should explore the relationships between these factors and their impacts on welfare and meat quality, report the economic value of these outcomes, and explore industry acceptability and adoptability of optimal preslaughter management practices.

Preslaughter factors affecting mobility, blood parameters, bruising, and muscle pH of finished beef cattle in the United States.

Decades of work have focused on reducing fear, stress, and discomfort in cattle during the preslaughter phase by improving and promoting animal handling, transportation, and management processes. Even still, there is limited information about the effects of preslaughter factors on animal welfare and meat quality outcomes in finished cattle in the United States. This study aimed to track individual animals through the slaughter process to identify preslaughter factors associated with key welfare and quality outcomes. A total of 454 cattle from one commercial slaughter facility were studied. Preslaughter factors assessed included distance traveled, truck waiting time, lairage density, lairage duration, and season. Animal characteristics, i.e., body weight, breed, and sex, were also recorded. One trained observer scored the mobility of all cattle using the North American Meat Institute's 1-4 scale (i.e., normal to extremely reluctant to move). Exsanguination blood was collected and analyzed for cortisol, creatine kinase, and lactate. Carcass bruising was scored using a modified version of the National Beef Quality Audit's bruise-scoring methodology (i.e., no bruise, one bruise ≤ the size of a deck of cards, one bruise > than the size of a deck of cards, and multiple bruises). Ultimate muscle pH was measured 32 to 36 h postmortem. Multi-predictor models were selected for each outcome variable using Akaike Information Criterion. Continuous outcome variables were analyzed using linear mixed-effect models and categorical outcome variables with mixed-effect logistic regression models. Longer truck waiting times were associated with increased cortisol (P = 0.04) and lactate (P = 0.02) concentrations. Similarly, increased lairage duration was associated with increased creatine kinase concentrations (P = 0.05) and the odds of cattle being bruised (P = 0.03). Less space allowance per animal in lairage was associated with increased odds of cattle having impaired mobility (P = 0.01). There was a seasonal effect for many of the measured outcomes; the summer season was associated with greater lactate concentrations (P < 0.0001), increased odds of impaired mobility (P < 0.0001), and increased odds of carcass bruising (P = 0.003). The findings of this study indicate that many of the preslaughter factors assessed influence critical welfare and meat quality outcomes of finished beef cattle, warranting future research and consideration.

Shock index is positively correlated with acute blood loss and negatively correlated with cardiac output in a canine hemorrhagic shock model.

OBJECTIVE: To determine whether shock index (SI) positively correlates with percentage blood loss and negatively correlates with cardiac output (CO) in a canine hemorrhagic shock model and whether SI and metabolic markers may be used as end point targets for resuscitation. ANIMALS: 8 healthy Beagles. PROCEDURES: Between September and December 2021, dogs underwent general anesthesia for experimental induction of hypotensive shock, with the total volume of blood removed, CO, heart rate, systolic blood pressure, base excess, blood pH, and concentrations of hemoglobin, lactate, ionized calcium recorded, and SI calculated at 4 time points (TPs): after anesthetic induction when the dog had been stable for 10 minutes (TP1), 10 minutes after the mean arterial pressure stabilized to a target of 40 mm Hg following jugular removal of up to 60% blood volume to induce hemorrhagic shock (TP2), 10 minutes after autotransfusion of 50% of the removed blood (TP3), and 10 minutes after autotransfusion of the remaining 50% of the removed blood (TP4). RESULTS: Mean SI increased between TP1 (1.08 ± 0.35) and TP2 (1.90 ± 0.73) and did not return to the prehemorrhage values for TP3 or TP4. SI correlated positively with percentage blood loss (r = 0.583) and negatively with CO (r = -0.543). CLINICAL RELEVANCE: An increase in SI may support diagnosis of hemorrhagic shock; however, SI cannot be used as the sole end point of resuscitation. Significant differences in blood pH, base excess, and lactate concentration suggested they may be useful markers of hemorrhagic shock and need for blood transfusion.

Sedative and cardiopulmonary effects of intramuscular combinations of hydromorphone, acepromazine, dexmedetomidine, and glycopyrrolate followed by intravenous propofol and inhalant isoflurane anesthesia in healthy dogs.

OBJECTIVE: To evaluate the sedative and cardiopulmonary effects of various combinations of acepromazine, dexmedetomidine, hydromorphone, and glycopyrrolate, followed by anesthetic induction with propofol and maintenance with isoflurane in healthy dogs. ANIMALS: 6 healthy adult female Beagles. PROCEDURES: Dogs were instrumented for hemodynamic measurements while anesthetized with isoflurane. Two hours after recovery, dogs received 1 of 4 IM combinations in a crossover design with 1 week between treatments: hydromorphone (0.1 mg/kg) and acepromazine (0.005 mg/kg; HA); hydromorphone and dexmedetomidine (0.0025 mg/kg; HD); hydromorphone, acepromazine, and dexmedetomidine (HAD); and hydromorphone, acepromazine, dexmedetomidine, and glycopyrrolate (0.02 mg/kg; HADG). Sedation was scored after 30 minutes. Physiologic variables and cardiac index were measured after sedation, after anesthetic induction with propofol, and every 15 minutes during maintenance of anesthesia with isoflurane for 60 minutes (target expired concentration at 760 mm Hg, 1.3%). RESULTS: Sedation scores were not significantly different among treatments. Mean ± SD cardiac index was significantly higher for the HA (202 ± 45 mL/min/kg) and HADG (185 ± 59 mL/min/kg) treatments than for the HD (88 ± 31 mL/min/kg) and HAD (103 ± 25 mL/min/kg) treatments after sedation and through the first 15 minutes of isoflurane anesthesia. No ventricular arrhythmias were noted with any treatment. CLINICAL RELEVANCE: In healthy dogs, IM administration of HADG before propofol and isoflurane anesthesia provided acceptable cardiopulmonary function with no adverse effects. This combination should be considered for routine anesthetic premedication in healthy dogs.

Small RNA profiling of Dengue virus-mosquito interactions implicates the PIWI RNA pathway in anti-viral defense.

BACKGROUND: Small RNA (sRNA) regulatory pathways (SRRPs) are important to anti-viral defence in mosquitoes. To identify critical features of the virus infection process in Dengue serotype 2 (DENV2)-infected Ae. aegypti, we deep-sequenced small non-coding RNAs. Triplicate biological replicates were used so that rigorous statistical metrics could be applied. RESULTS: In addition to virus-derived siRNAs (20-23 nts) previously reported for other arbovirus-infected mosquitoes, we show that PIWI pathway sRNAs (piRNAs) (24-30 nts) and unusually small RNAs (usRNAs) (13-19 nts) are produced in DENV-infected mosquitoes. We demonstrate that a major catalytic enzyme of the siRNA pathway, Argonaute 2 (Ago2), co-migrates with a ~1 megadalton complex in adults prior to bloodfeeding. sRNAs were cloned and sequenced from Ago2 immunoprecipitations. Viral sRNA patterns change over the course of infection. Host sRNAs were mapped to the published aedine transcriptome and subjected to analysis using edgeR (Bioconductor). We found that sRNA profiles are altered early in DENV2 infection, and mRNA targets from mitochondrial, transcription/translation, and transport functional categories are affected. Moreover, small non-coding RNAs (ncRNAs), such as tRNAs, spliceosomal U RNAs, and snoRNAs are highly enriched in DENV-infected samples at 2 and 4 dpi. CONCLUSIONS: These data implicate the PIWI pathway in anti-viral defense. Changes to host sRNA profiles indicate that specific cellular processes are affected during DENV infection, such as mitochondrial function and ncRNA levels. Together, these data provide important progress in understanding the DENV2 infection process in Ae. aegypti.

MicroRNA Expression Changes and Integrated Pathways Associated With Poor Outcome in Canine Osteosarcoma.

MicroRNAs (miRNA) are small non-coding RNA molecules involved in post-transcriptional gene regulation. Deregulation of miRNA expression occurs in cancer, and miRNA expression profiles have been associated with diagnosis and prognosis in many cancers. Osteosarcoma (OS), an aggressive primary tumor of bone, affects ~10,000 dogs each year. Though survival has improved with the addition of chemotherapy, up to 80% of canine patients will succumb to metastatic disease. Reliable prognostic markers are lacking for this disease. miRNAs are attractive targets of biomarker discovery efforts due to their increased stability in easily obtained body fluids as well as within fixed tissue. Previous studies in our laboratory demonstrated that dysregulation of genes in aggressive canine OS tumors that participate in miRNA regulatory networks is reportedly disrupted in OS or other cancers. We utilized RT-qPCR in a 384-well-plate system to measure the relative expression of 190 miRNAs in 14 canine tumors from two cohorts of dogs with good or poor outcome (disease-free interval >300 or <100 days, respectively). Differential expression analysis in this subset guided the selection of candidate miRNAs in tumors and serum samples from larger groups of dogs. We ultimately identified a tumor-based three-miR Cox proportional hazards regression model and a serum-based two-miR model, each being able to distinguish patients with good and poor prognosis via Kaplan-Meier analysis with log rank test. Additionally, we integrated miRNA and gene expression data to identify potentially important miRNA-mRNA interactions that are disrupted in canine OS. Integrated analyses of miRNAs in the three-miR predictive model and disrupted genes from previous expression studies suggest the contribution of the primary tumor microenvironment to the metastatic phenotype of aggressive tumors.

Contrast therapy: Tissue heating and cooling properties within the equine distal limb.

BACKGROUND: Rehabilitation of tendon injuries in horses often involves cryotherapy to reduce inflammation and occasionally tissue heating to increase collagen extensibility. The application of alternating cold and hot (ie contrast therapy) is widely used in human physical therapy; however, its utility in equine rehabilitation is largely unknown. OBJECTIVES: The objectives of this study were to (a) assess if the equipment could achieve therapeutic tissue temperatures (<15 and >40°C) at different tissue depths relative to the digital flexor tendons and (b) evaluate the time-temperature profiles during serial heating and cooling cycles using a contrast therapy device. STUDY DESIGN: In vivo experiment. METHODS: In 4 adult horses with normal forelimb digital flexor tendons, fine-wire temperature probes were placed superficially on the skin and implanted subcutaneously, deep to the superficial digital flexor tendon (SDFT) and deep to the deep digital flexor tendon (DDFT). Temperatures were recorded over three complete thermal (hot-cold) cycles. Minimum and maximum temperatures were recorded and the rate of temperature changes and the areas underneath the time-temperature curves (ie thermal load) were calculated. RESULTS: Minimum and maximum tissue temperatures (°C) included: superficial skin [12.6 ± 1.0; 42.4 ± 2.4], subcutaneous tissues [14.1 ± 0.8; 42.3 ± 2.2], deep to the SDFT [15.6 ± 0.8; 41.7 ± 2.6] and deep to DDFT [25.1 ± 2.0; 38.0 ± 3.5]. An initial rapid rate of tissue temperature change between 3.2 and 4.3°C/min occurred within tissues to the depth of the DDFT. Tissue thermal loads during heating ranged from 255 to 607°C*second and from 309 to 780°C*second during tissue cooling, with the lower values noted deep to the DDFT. MAIN LIMITATIONS: Unknown clinical efficacy in diseased tissues. CONCLUSIONS: The applied contrast therapy was consistently able to induce cooling and heating of tissues to the depth of the DDFT.

Female Urine-induced Ultrasonic Vocalizations in Male C57BL/6J Mice as a Proxy Indicator for Postoperative Pain.

Objectively recognizing postoperative pain in mice is challenging, making it difficult to determine an appropriate postoperative analgesic regimen. Adult male mice produce ultrasonic vocalizations after exposure to adult female urine (FiUSV). To determine if FiUSV can be used as a indicator of postoperative pain, FiUSV produced by male C57BL/6J mice were assessed for 5 d before and after vasectomy or sham surgery with or without sustained-release buprenorphine. Postoperative pain was assessed by monitoring vocalization using an ultrasonic microphone and by evaluating orbital tightness, posture, and piloerection at postoperative time points. Before vasectomy or sham surgery, 25 of 38 male mice produced FiUSV on 4 of 5 d (143 ± 93 FiUSV). Vasectomized mice without postoperative analgesia produced significantly fewer FiUSV (59 ± 26 FiUSV) compared with baseline (212 ± 102 FiUSV) at 4 h postoperatively, but returned to baseline by 28 h. Vasectomized mice treated with buprenorphine and sham-surgery mice had no change in FiUSV from baseline at any time point after surgery. Activity was decreased compared with baseline in vasectomized mice, regardless of receiving postoperative analgesia or not, but only at the 4-h time point. There were no differences in behavior scores between vasectomized mice and sham-surgery mice at any time point. These results show that FiUSV can be used to detect postoperative pain in male C57BL/6J mice after vasectomy.