Evaluation of clopidogrel response in healthy cats using a novel viscoelastic test and thromboelastography.

Introduction: Cats with cardiomyopathy face an increased risk of arterial thromboembolism (ATE). Although clopidogrel is frequently utilized to mitigate this risk, feline responses to this therapy exhibit variability. This study evaluated 2 viscoelastic devices, thromboelastography (TEG) and Viscoelastic Coagulation Monitor (VCM), for monitoring clopidogrel in cats in comparison to light transmission aggregometry (LTA). Methods: Twenty-eight healthy cats received clopidogrel for 7 days. Blood was collected at baseline and after treatment for analysis by TEG, VCM, and LTA. Results: On LTA, maximum amplitude, slope, and area under the curve (AUC) significantly decreased after treatment (p < 0.0001). On VCM, maximum clot firmness (MCF) significantly increased after treatment (p = 0.002). On TEG, R-time significantly prolonged (p = 0.024), while K and alpha angle significantly changed (p = 0.0002 and p = 0.0014, respectively). There was a moderate negative correlation between TEG R-time and LTA AUC (r = -0.39, p = 0.042). Eight cats were identified as non-responders to clopidogrel. Of the 8 non-responders, 6 (75%) had shortened R time after treatment. VCM appeared to be less discriminatory in identifying non-responders. Discussion: LTA remained the gold standard of monitoring clopidogrel treatment in cats. Unexpected changes on VCM and TEG were likely related to high interindividual and assay variability and increased sensitivity of feline platelets. R-time on TEG may have potential utility for point-of-care monitoring of clopidogrel response in cats.

Effects of a single subcutaneous dose of enoxaparin on veterinary viscoelastic coagulation monitor variables in healthy cats: Double blind, placebo controlled cross-over trial.

BACKGROUND: Cats placed on anticoagulant medication require frequent monitoring. The veterinary viscoelastic coagulation monitor (VCM-Vet) could provide a convenient and cost-effective monitoring, enabling therapeutic decision making. HYPOTHESIS/OBJECTIVES: Enoxaparin will lead to changes in VCM-Vet variables and these will correlate with antiXa activity. ANIMALS: Twenty-one healthy cats. METHODS: Cats were randomized to receive either enoxaparin (1 mg/kg) subcutaneously or 0.9% NaCl (equal volume) and crossed over with a 7-day washout period. The investigators were blinded to group allocation until data analysis. Jugular blood samples were drawn at time 0, and 2, 4, and 8 hours after injection for VCM-Vet analysis within 2 min of collection. Citrated plasma was frozen at -80°C for antiXa activity analysis. A Generalized Linear Model was completed to assess changes between baseline measurements and all time points. RESULTS: Significant differences between the enoxaparin-treated cats and controls at for T0h and T2h were found and presented as mean ± SD for clotting time (enoxaparin, 593.4 ± 78.0 s; control, 448.5 ± 50.3 s, P < .001), clot formation time (enoxaparin, 183.1 ± 41.7 s; control, 155.4 ± 28.0 s, P = .001), and alpha angle (enoxaparin, 52.4 ± 6.1°; control, 56.9 ± 3.7 s, P = .003). AntiXa activity was significantly different between T0 and all other timepoints for the enoxaparin group (P < .001). There was no correlation between changes in clotting time and antiXa activity. CONCLUSIONS AND CLINICAL IMPORTANCE: The VCM-Vet detects a difference at 2 hours after single-dose enoxaparin administration and it can be useful for anticoagulant therapy monitoring in cats.

Preliminary evaluation of reference intervals for a point-of-care viscoelastic coagulation monitor (VCM Vet) in healthy adult horses.

OBJECTIVE: To evaluate a point-of-care viscoelastic coagulation monitor (VCM Vet) for use in horses by assessing variability between devices and establish reference intervals (RIs) for healthy adult horses. DESIGN: Prospective observational study. SETTING: Two university teaching hospitals. ANIMALS: Healthy adult horses (n = 68). INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Blood collected by direct jugular venipuncture was applied directly from the syringe into 2 VCM Vet cassettes to establish coefficients of variation (CVs) and RIs for reported parameters of clotting time (CT), clot formation time (CFT), alpha angle, amplitude at 10 and 20 minutes, maximum clot firmness, and lysis index at 30 and 45 minutes. CVs for each parameter were within clinical tolerance. There was a significant difference in CT between institutions (P < 0.001). Differences in CV were found between institutions for CT (P = 0.003) and CFT (P = 0.01). Healthy horse RIs were calculated for the overall data set and each individual institution. Calculated RIs were as follows: CT, 255.6-1233.9 seconds; CFT, 89.4-581 seconds; alpha angle, 11.4-53.6°; maximum clot firmness, 18-37.7; lysis index at 30 minutes, 97.3%-102.1%; lysis index at 45 minutes, 80.8%-103.3%; amplitude at 10 minutes, 8.7-28.3; and amplitude at 20 minutes, 17.4-35.7. CONCLUSIONS: VCM Vet is a repeatable and practical option for rapid point-of-care assessment of hemostasis in horses but has a wide RI and is susceptible to variability. Establishment of institution-specific RIs is recommended.

Prospective investigation of factors associated with success on the American College of Veterinary Emergency and Critical Care certification examination (2016-2018).

OBJECTIVE: To assess the association of candidate attributes and residency training factors with success on the American College of Veterinary Emergency and Critical Care (ACVECC) board certification examination and to develop multivariable models of first-attempt success. DESIGN: Prospective survey-based study. SETTING: Post-assessment ACVECC examination candidates. ANIMALS: None. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Comprehensive surveys were distributed to ACVECC examination candidates in 2016 to 2018 after completion of their assessments, but prior to publication of examination results. Unique anonymous candidate identification numbers were used to match survey responses to outcome data from the office of the ACVECC Executive Secretary. After curation to retain only the first response from each candidate, there were 97 unique candidate responses available for analysis. Univariate analyses identified multiple factors associated with first-attempt success and multiple differences between academic and private practice residency programs. Multivariable logistic regression modeling suggested that 5 factors were independently associated with first-attempt success on the ACVECC examination, specifically younger age, more weeks of study prior to the examination, training at a facility with more ACVECC Diplomates, training at a facility with more ACVECC residents, and having no requirement to manage both Emergency Room (ER) and Critical Care (CC) cases simultaneously. CONCLUSIONS: Numerous resident and training center factors are associated with success in the ACVECC board certification examination. Residents and training centers might be able to use these data to enhance training, but caution must be exercised because these data are associative only.

Can veterinary medicine improve diversity in post-graduate training programs? Current state of academic veterinary medicine and recommendations on best practices.

The American Association of Veterinary Clinicians (AAVC) convened a Diversity, Equity, and Inclusivity working group in March 2021 to address the limited diversity (including but not limited to ethnic, racial, and cultural diversity) in clinical post-DVM graduate training programs and academic faculty. Concurrent with a working group formation, the AAVC developed a strategic plan. The central mission of the AAVC is to develop, support, and connect academic leaders to fuel the future of the veterinary medical profession. House officers and their training programs are central to all goals outlined in the strategic plan. Amongst other strategic goals, the working group identified best practices for intern and resident recruitment and selection. We report herein from the current health profession literature ways to identify and recruit talented, diverse candidates especially those with non-traditional (atypical) preparation and experience. We also provide recommendations on best practices for intern and resident selection. This document highlights holistic approaches, some of which are incrementally being incorporated into the Veterinary Intern Resident Matching Program application, that emphasize diversity as a selection criteria for intern and resident selection an important step towards building a more resilient and inclusive workforce. These include expanding candidate assessment beyond grades and class rank into a more standardized method for screening candidates that includes consideration of life experiences and talents outside of veterinary medicine.

Comparison of healthy blood donor Greyhounds and non-Greyhounds using a novel point-of-care viscoelastic coagulometer.

OBJECTIVE: To measure and compare viscoelastic coagulation in 2 canine blood donor populations using a novel, point-of-care device (VCM Vet Analyzer, VCM). DESIGN: Cohort study. SETTING: Academic and commercial veterinary blood banks. ANIMALS: Non-Greyhounds from community-based blood donor program and Greyhounds from a blood bank colony. INTERVENTION: Blood was collected from all dogs via direct venipuncture for a complete hemogram, biochemistry, and point-of-care viscoelastic coagulation. MEASUREMENT AND MAIN RESULTS: All biochemical measurements for all dogs in Group NG (n = 38, non-Greyhounds) and Group G (n = 53, Greyhounds) were within local reference intervals. Hematology data showed significant statistical differences between groups in hemoglobin, RBC, platelet, and WBC concentrations. Group G demonstrated lower maximum clot firmness (MCF) with 17 VCM units (26 VCM units in Group NG), increased lysis with 30 VCM units at 30 minutes (LI30) and 27 VCM units at 45 minutes (LI45) (86 VCM units LI30 and 85 VCM units LI45 in Group NG), and decreased amplitude of 13 VCM units 10 minutes (A10) after clot time (CT) and 6 VCM units 20 minutes after CT (A20) (18 VCM units [A10] and 22 VCM units [A20] in Group NG). CONCLUSION: This study found differences between healthy Greyhound and non-Greyhound blood donors in measures of clot strength and fibrinolysis as measured by the VCM. Whereas Greyhound have unique hematologic and hemostatic profiles, these measured viscoelastic differences are important to note prior to and following surgical intervention to aid in clinical decision-making if bleeding complications develop.

An in vitro study of canine cryopoor plasma to correct vitamin K-dependent coagulopathy in dogs.

OBJECTIVE: To compare the efficacy of fresh frozen plasma (FFP) with cryopoor plasma (CPP) to treat vitamin K-dependent factor deficiency in a canine in vitro setting. DESIGN: In vitro laboratory study. SETTING: University veterinary medical teaching hospital. ANIMALS: Seven units of FFP and 6 units of CPP from unique canine donors from the university veterinary blood bank. INTERVENTIONS: Canine FFP was adsorbed by oral barium sulfate suspension to mimic vitamin K-dependent coagulopathy. A sequential mixing study was completed by adding FPP or CPP to the adsorbed plasma. Measurements of prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen, and factor activities of factors II, VII, and IX (FII, FVII, and FIX) were compared between the 2 treatment groups. MEASUREMENTS AND MAIN RESULTS: When comparing the sequential addition of CPP or FPP to adsorbed plasma, the following had no statistical significance: PT (P = 0.94), aPTT (P = 0.66), FII (P = 0.05), and FIX (P = 0.90). There was a dose-dependent decrease with PT and aPTT and a dose-dependent increase with FII and FIX. In contrast, after the addition of either CPP or FFP, there was a significant difference between the treatment groups for the concentration of fibrinogen (P = 0.005) and activity of FVII (P = 0.044), with FFP resulting in a greater concentration of fibrinogen and CPP resulting in a greater concentration of FVII. Measurements of factor X (FX) were initially included in the study but were later excluded because FX appeared to be continually adsorbed even after the addition of CPP or FFP. CONCLUSIONS: CPP partially corrected the coagulation times and concentration of vitamin K-dependent coagulation factors to the same degree as FFP. CPP, generally less expensive than FFP, may provide an alternative treatment option for vitamin K-dependent coagulopathies, although in vivo testing is needed.

Use of Thromboelastography in Clinical Practice.

Viscoelastic testing, such as thromboelastography or thromboelastometry, is performed on whole-blood samples, which include both soluble plasma factors as well as blood cells and platelets bearing tissue factor and phospholipid. This methodology allows identification of fibrinolysis and can provide analysis of platelet function. Viscoelastic testing has become increasingly accessible and popular in emergency and critical care settings in recent years and can provide important information for the diagnosis and management of patients with hemostatic disorders. This article discusses the principles and interpretation of viscoelastic testing, application to small animal emergency and critical care medicine, and potential advantages and disadvantages.

Establishment of a reference interval for a novel viscoelastic coagulometer and comparison with thromboelastography in healthy cats.

BACKGROUND: Viscoelastic analysis provides information on the dynamics and strength of clot formation as well as clot stability. A novel point-of-care viscoelastic test (Viscoelastic Coagulation Monitor Vet, VCM Vet) could be more cost-effective, simpler to use, and more portable than thromboelastography (TEG). OBJECTIVES: The primary aim of this study was to establish a feline reference interval (RI) for the VCM Vet. A secondary aim was to compare VCM Vet analysis with TEG in healthy cats. METHODS: Fifty-six healthy cats were enrolled in this study. Linear regression was completed to determine whether age and CBC parameters were associated with the VCM Vet parameters and if TEG parameters were correlated with VCM Vet data. Statistical significance was set at P < .05. RESULTS: Fifty-three VCM Vet tracings were used to determine RIs for healthy cats. The determined RIs were: clot time (CT) 104-438 seconds; clot formation time (CFT) 104.5-488 seconds; alpha angle (AA) 30.5°-70°; a10 13.8-32.7 VCM units; a20 19.2-40.1 VCM units; maximum clot formation (MCF) 22.5-44.8 VCM units; Lysis Index 30 (Li30) 92.9%-100.9%; and Lysis Index 45 (Li45) 92%-100%. Linear regression identified a strong positive correlation between the CT and R-time measured using the VCM Vet and TEG methods, respectively; no other parameters were correlated. CONCLUSIONS: The use of VCM Vet is feasible in cats, and we determined the first described feline RIs for this test. In general, the VCM Vet data did not correlate with TEG in healthy cats.

Obstructive Tracheal Necrosis in a Dog Secondary to Smoke Inhalation Injury-Case Report.

A 4-year-old Siberian Husky mix was referred to the emergency service of the University of California Davis Veterinary Medical Teaching Hospital after being found unconscious in a housefire. Upon arrival, the dog was conscious and panting with normal breathing effort. The dog was initially treated with oxygen therapy to minimize the risk of carbon monoxide toxicosis. Progressive agitation with paroxysmal episodes of increased respiratory effort and increased upper airway sounds were noted ~48 h after presentation. Hypoxemia was then documented. Clinical signs continued to progress despite supportive measures, and five days after initial presentation mechanical ventilation was deemed indicated. Following anesthetic induction, endotracheal intubation was performed. Capnography and peak inspiratory pressures recorded on the mechanical ventilator were consistent with airway obstruction. Diffuse intraluminal tracheal obstruction with grossly necrotic tracheal tissue was confirmed using fiber optic tracheoscopy. The patient was humanely euthanized due to grave prognosis. At necropsy, the tracheal lumen was obstructed by sloughed, necrotic tracheal mucosa. This is the first report describing a severe delayed intrathoracic large airway complication secondary to smoke inhalation in a dog.

Severe hypernatremia and transient azotemia in a cat following inadvertent intravenous administration of a commercial polyethylene glycol solution.

OBJECTIVE: To describe the clinical signs, clinicopathologic abnormalities, treatment, and outcome after IV administration of polyethylene glycol 3350 (PEG3350) in a cat. CASE SUMMARY: A cat was inadvertently administered 6 g/kg of PEG3350 in electrolyte solution, IV, resulting in severe hypernatremia (203 mmol/L), diffuse encephalopathy, hemolysis, and moderate azotemia. The hemolysis and acute kidney injury observed immediately following PEG3350 administration resolved with supportive care. Administration of IV and oral electrolyte-free water slowly corrected the hypernatremia and the neurologic signs subsequently improved. Complete resolution of clinical signs was documented one month following hospital discharge. The PEG3350 concentrations in serum, plasma, and urine samples confirmed toxic exposure to PEG3350. Efficacy of treatment was evident by decreasing concentrations of PEG3350 in serum after the first 24 hours of treatment. Renal elimination of PEG3350 was significant and PEG3350 was still detected in the urine 17 days after exposure. NEW INFORMATION PROVIDED: This is the first report to describe the clinical signs and clinicopathologic abnormalities in a cat intoxicated with IV PEG3350. Potential pathophysiologic mechanisms are discussed, and the successful supportive medical treatment is outlined.

Assessment of a dimethyl sulfoxide-stabilized frozen canine platelet concentrate.

OBJECTIVE: To assess platelet count, mean platelet volume (MPV), metabolic characteristics, and platelet function in a dimethyl sulfoxide (DMSO)-stabilized canine frozen platelet concentrate (PC). SAMPLE POPULATION: 11 units of a commercial frozen PC in 6% DMSO and fresh platelet-rich plasma from 6 healthy control dogs. PROCEDURES: PCs were thawed, and the following data were collected: thaw time, platelet count, MPV, pH, PCO2, and PO2 and HCO3-, glucose, and lactate content. Phosphatidylserine translocation was determined by use of flow cytometry. Fresh platelet-rich plasma from healthy dogs served as a source of control platelets for flow cytometric analysis. RESULTS: At thaw, the platelet count in the frozen PC ranged from 243,000 to 742,000 platelets/microL. Median platelet count of paired samples was 680,000 platelets/microL and decreased significantly to 509,000 platelets/microL at 2 hours after thaw. Median MPV at thaw was 11.15 femtoliters and was stable after 2 hours. Compared with fresh platelets, frozen PC had increased amounts of phosphatidylserine in the outer leaflet of the platelet membrane in the resting (ie, not treated with thrombin) state (19% vs 99%, respectively) and alterations in cellular morphology, all of which were consistent with platelet activation. CONCLUSIONS AND CLINICAL RELEVANCE: Results of this in vitro study indicated that there was a decrease in platelet quantity and function as well as an increase in platelet activation during the freeze-and-thaw process in DMSO-stabilized canine frozen PC. In vivo effects on PC remain to be determined.

Clinical, clinicopathologic, and radiographic findings in dogs with aspiration pneumonia: 88 cases (2004-2006).

OBJECTIVE: To evaluate clinical, clinicopathologic, and radiographic findings in dogs with aspiration pneumonia. DESIGN: Retrospective case series. Animals-88 dogs with aspiration pneumonia. PROCEDURES: History, physical examination findings, and clinicopathologic data were obtained from medical records and analyzed for all 88 dogs. Thoracic radiographic findings for all dogs were reviewed to determine the type and location of pulmonary infiltrates. RESULTS: Aspiration pneumonia was evident at admission to the hospital in 65 (74%) dogs and developed during hospitalization in 23 (26%) dogs. Less than half of these affected dogs had high values for rectal temperature, heart rate, or respiratory rate; however, most (68%) affected dogs had increased, decreased, or adventitious lung sounds. Neutrophilia with a left shift was a common finding. Hypoalbuminemia was detected in 31 of 58 (53%) dogs. Hypoxemia and a high alveolar-arterial gradient in partial pressure of oxygen were detected in 22 of 28 (79%) dogs and 27 of 28 (96%) dogs, respectively. Among the 88 dogs, thoracic radiography revealed a predominantly alveolar infiltrate in 65 (74%) dogs and an interstitial pattern in 23 (26%) dogs; a single lung lobe was affected in 46 (52%) dogs, most commonly the right middle lung lobe (21/46 [46%] dogs). CONCLUSIONS AND CLINICAL RELEVANCE: In dogs, aspiration pneumonia was often associated with abnormalities in pulmonary auscultation in the absence of objective changes in physical examination findings. However, neutrophilia, hypoalbuminemia, and hypoxemia were frequently detected, and radiographic evidence of infiltrates in the right middle lung lobe was common.

Etiology and clinical outcome in dogs with aspiration pneumonia: 88 cases (2004-2006).

OBJECTIVE: To evaluate the number and types of underlying disorders detected in dogs with aspiration pneumonia and determine the survival rate among affected dogs. DESIGN: Retrospective case series. Animals-88 dogs with aspiration pneumonia. PROCEDURES: Medical records were reviewed to identify disease processes that could result in aspiration pneumonia. To assess outcome (ie, survival to discharge from the hospital or nonsurvival), dogs were grouped by the type and number of underlying disease processes. Duration of hospitalization and radiographic severity of disease were evaluated with regard to case outcome. RESULTS: As the cause of aspiration pneumonia, a single underlying disorder was identified in 60 of the 88 dogs; 2 or more diseases were identified in the remaining dogs. Esophageal disease (n = 35), vomiting (34), neurologic disorders (24), laryngeal disease (16), and postanesthetic aspiration (12) were identified most commonly. Overall, 68 dogs survived to discharge from the hospital (survival rate, 77%). Survival rates were comparable among dogs regardless of the underlying cause of aspiration pneumonia. Radiographic severity of disease and duration of hospitalization did not influence survival. CONCLUSIONS AND CLINICAL RELEVANCE: Among these study dogs, aspiration pneumonia was associated with a high survival rate. The presence of more than 1 underlying disease associated with aspiration pneumonia did not adversely impact survival rate. Interestingly, radiographic severity of disease and duration of hospitalization were not associated with overall survival rate.

Platelet function in clinically healthy cats and cats with hypertrophic cardiomyopathy: analysis using the Platelet Function Analyzer-100.

BACKGROUND: There is currently no simple analytical tool for the evaluation of hypercoagulability in cats. The Platelet Function Analyzer-100 (PFA-100; Dade Behring Inc., Deerfield, IL, USA) is a bench-top machine that evaluates platelet function by measuring closure time (CT) in citrated whole blood under high shear conditions. We hypothesized that cats with hypertrophic cardiomyopathy (HCM) have up-regulated platelet function, which shortens their CT and increases their risk for thromboembolic events. OBJECTIVES: The goals of this study were to: (1) establish a feline reference interval for CT using the PFA-100, (2) measure CT in blood from cats with HCM, and (3) determine if there is a measurable difference between the CT of healthy cats compared with cats with HCM. METHODS: Citrated blood samples from 42 clinically healthy cats and 30 cats with HCM were analyzed according to manufacturer's specifications. CT was measured in triplicate and the mean value was used for analysis. Transformed data were compared between clinically healthy cats and cats with HCM using a Student's t-test, and among cats with mild, moderate, or severe HCM using ANOVA. RESULTS: The median CT of clinically healthy cats was 64 seconds (range 43-176 seconds). The median CT of cats with HCM was 74 seconds (range 48-197 seconds). There was no significant difference in CT between cats with HCM and clinically healthy cats. There also were no significant differences in cats with mild, moderate, or severe HCM. CONCLUSIONS: A feline reference interval for PFA-100 CT will be useful in future studies of platelet function in cats. Cats with HCM do not have shorter CTs when compared with clinically healthy cats.

Analysis of the first-time pass rate of the American College of Veterinary Emergency and Critical Care certifying examination (2010-2015).

OBJECTIVES: To disseminate information regarding the annual pass rates for the American College of Veterinary Emergency and Critical Care (ACVECC) certifying examination. To compare the first-time pass rates (FTPR) of ACVECC residents trained in academic and private practice settings. DESIGN: Retrospective study. SETTING: ACVECC examination. ANIMALS: None. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Anonymized ACVECC examination performance data from 2010-2015 inclusive were analyzed. Overall pass rates and FTPR were calculated for all candidates and categorized by type of residency training program. The overall pass rate for all candidates was 64.3%. The median pass rate for the 6-year period was 63.8% [IQR 59.3-67.3%]. The FTPR for residents trained in academic programs was significantly higher than for residents trained in private practice (77.1% vs 47.2%, P < 0.0001). When residents were subdivided by species-focus of training program, there was no significant difference between academic versus private practice training programs for large-animal candidates (P = 0.2), but there remained a significant difference between residency training programs for small-animal candidates (P < 0.0001). CONCLUSIONS: Between 2010 and 2015 residents trained in academic training programs were significantly more likely to pass the ACVECC certifying examination compared to those trained in private practice training programs. The causes of this difference are uncertain, are likely multifactorial and warrant further investigation.

Incidence of chyloabdomen diagnosis in dogs and cats and corresponding clinical signs, clinicopathologic test results, and outcomes: 53 cases (1984-2014).

OBJECTIVE To determine the incidence of chyloabdomen diagnosis in cats and dogs and characterize and compare between species the corresponding clinical signs, clinicopathologic test results, and outcomes. DESIGN Retrospective case series. ANIMALS 36 cats and 17 dogs in which chyloabdomen was diagnosed at a veterinary teaching hospital between 1984 and 2014. PROCEDURES Medical records were reviewed, and data retrieved included patient signalment; clinical signs at initial evaluation; results of physical examination, diagnostic tests, and imaging studies; and outcomes. Survival analyses, descriptive statistics, and comparisons between species were completed. RESULTS The incidence of chyloabdomen at the veterinary teaching hospital during the study period was 2.0 cases/100,000 admissions for cats and 2.8 cases/100,000 admissions for dogs. The mean age at diagnosis of chyloabdomen in cats was 11.3 years, compared with 6.9 years in dogs. The most common clinical signs in dogs and cats combined were lethargy (39/51 [76%]) and anorexia (37/51 [73%]), but fewer (23/53 [43%]) had abdominal distention. Chylothorax was a common comorbidity (25/53 [47%]), with malignant neoplasia being the most common underlying diagnosis (24/53 [45%]). Survival analyses included 44 patients; median survival time from diagnosis of chyloabdomen was 31 days overall, 8 days for patients with malignant neoplasia, and 73 days for patients without neoplasia. CONCLUSIONS AND CLINICAL RELEVANCE There were multiple causes of chyloabdomen in dogs and cats of the study, and outcome depended on underlying cause. Because of this and the rarity of chyloabdomen, a multicenter prospective study of disease progression, treatment response, and clinical outcome for dogs and cats with chyloabdomen is needed.

Multicenter in vitro thromboelastography and thromboelastometry standardization.

OBJECTIVE: To establish and compare the repeatability and reproducibility of activated thromboelastography (TEG) and thromboelastometry (ROTEM) assays. DESIGN: Multicenter in vitro test standardization. SETTING: Veterinary academic centers. ANIMALS: Test samples were obtained from normal, healthy dogs. Sixty identical 5 mL aliquots of canine platelet-rich plasma collected by apheresis, frozen in 6% dimethyl sulfoxide, were tested initially. Sixty identical 6 mL aliquots of canine fresh frozen plasma with admixed cryoprecipitate were subsequently evaluated. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Frozen study samples, quality controls, reagents, and consumables were distributed to participating centers (7 TEG and 3 ROTEM). TEG centers analyzed study samples with kaolin and tissue factor activated assays; ROTEM centers ran proprietary ellagic acid activated and tissue factor activated assays. All machines underwent quality control prior to sample analysis. Within- and between-center coefficients of variation (CVs) were calculated and compared using Mann-Whitney tests and calculation of intraclass correlation coefficients. Within and between centers, individual parameters for both TEG and ROTEM assays were comparable. Both within-center and between-center CVs varied markedly (0.7-120.5% and 1.4-116.5%, respectively) with assay type, instrument, and parameter. CVs for equivalent parameters were not significantly different between the 2 platforms. Intraclass correlation coefficients suggested moderate agreement between centers. In general, individual parameter CVs for platelet-rich plasma samples were lower in TEG centers, while CVs for canine fresh frozen plasma with admixed cryoprecipitate samples were lower in ROTEM centers. CONCLUSIONS: More variation within and between centers was identified than anticipated, but some parameters such as alpha angle were repeatable and reproducible. Sample types for future multicenter standardization efforts will require further optimization and may need to be adapted separately to each platform. Individual centers using viscoelastic tests for evaluation and management of clinical patients should take steps to minimize preanalytical and analytical sources of variation.

In vitro comparison of the effects of two forms of hydroxyethyl starch solutions on platelet function in dogs.

OBJECTIVE: To evaluate the effect of 2 hydroxyethyl starch (HES) preparations (ie, HES solution with a molecular weight of 600 kd and a degree of substitution of 0.7 [HES 600/0.7] and a calcium-containing polyionic HES solution with a molecular weight of 670 kd and a degree of substitution of 0.75 [HES 670/0.75]) on canine platelet function. SAMPLE POPULATION: Blood samples from 10 healthy adult dogs. PROCEDURES: Dilution of citrated whole blood was performed with saline (0.9% NaCl) solution, HES 600/0.7, and HES 670/0.75 at ratios of 1:9 (ie, 1 part saline solution or colloid to 9 parts whole blood) and 1:3. Measurements of time to platelet plug formation in a capillary tube (ie, closure time) were made by use of a bench-top platelet function analyzer with collagen and ADP platelet agonists. RESULTS: Mean baseline closure time was 68.0 +/- 15.3 seconds. A 1:3 dilution of whole blood with saline solution, HES 600/0.7, and HES 670/0.75 resulted in mean closure times of 85.8 +/- 15.7 seconds, 100.6 +/- 18.6 seconds, and 101.6 +/- 16.2 seconds, respectively. Closure time following 1:3 dilution of whole blood with saline solution was significantly different from baseline and from 1:9 dilution with saline solution. Closure time following 1:3 dilution of whole blood with HES 670/0.75 was significantly different from baseline, 1:3 and 1:9 dilutions with saline solution, and 1:9 dilutions with HES 600/0.7 or HES 670/0.75. CONCLUSIONS AND CLINICAL RELEVANCE: Saline solution, HES 600/0.7, and HES 670/0.75 affect canine platelet function by prolonging closure times; HES solutions prolonged closure time to a greater extent than saline solution.

Risk factors associated with outcome in dogs with tetanus: 38 cases (1987-2005).

OBJECTIVE: To assess the clinical course of disease and risk factors associated with outcome in dogs with tetanus. DESIGN: Retrospective case series. ANIMALS: 38 dogs with tetanus. PROCEDURES: Data were collected from medical records of dogs with tetanus, including signalment; wound characteristics; initial clinical signs; severity of worst clinical signs; time to wound management, antimicrobial treatment, and antitoxin administration; and 28-day survival rate. Statistical analyses were performed to evaluate relationships between the potentially predictive variables and disease progression and outcome. RESULTS: The 28-day survival rate was 77% (among 35 uncensored dogs). The most common initial clinical signs in affected dogs were ocular (n = 18) and facial (11) abnormalities. Nineteen dogs progressed to recumbency with severe muscle spasms, and 14 dogs had high or low heart rate or blood pressure values. Eight dogs died or were euthanized because of complications of tetanus. There was a significant association between younger age and development of more severe clinical signs. Furthermore, a significant inverse relationship between development of severe clinical signs and survival was identified. There was no association between earlier initiation of wound management, antimicrobial administration, or antitoxin administration and either progression of signs or 28-day survival rate. Wound type was not associated with 28-day survival rate. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that younger dogs with tetanus may be more likely to develop severe clinical signs. The prognosis for survival in dogs with tetanus is good if abnormalities in heart rate or blood pressure values do not develop.