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Dogs that had splenectomy are predisposed to fatal thrombotic conditions, and thrombocytosis is a risk factor for post-splenectomy hypercoagulability. However, in veterinary medicine, there are no specific therapeutic approaches for managing this hypercoagulability. This study aimed to determine the preventive effect of clopidogrel on post-operative hypercoagulability during the first 2 weeks post-splenectomy in dogs with splenic masses. This study included 12 dogs that had splenectomy. Seven dogs received no treatment (group A), and five were treated with clopidogrel (group B). Clopidogrel was loaded at 10 mg/kg on day 2 and continued at 2 mg/kg until day 14. Blood samples were collected on the day of surgery and 2, 7, and 14 days after splenectomy in both groups. In group B, thromboelastography (TEG) was performed on the same days. In group A, there was significant elevation of platelet counts on days 7 ( p  = 0.007) and 14 ( p  = 0.001) compared to day 0. In group B, the platelet counts were significantly elevated on day 7 ( p  = 0.032) but no significant difference was found on day 14 compared to day 0. Platelet counts on day 14 were significantly higher in group A than in group B ( p  = 0.03). The lower platelet counts were correlated with alterations in TEG parameters, and no significant differences were found in the K and α-angle values at all postoperative assessment points compared to day 0. Our study suggests that clopidogrel may reduce post-operative thrombocytosis and hypercoagulability in dogs that undergo splenectomy for splenic masses.

Background: Pulmonary hypertension (PH) in dogs with myxomatous mitral valve disease (MMVD) is caused by increased pulmonary venous pressure. Thrombosis, vascular remodeling, and vasoconstriction mediated by platelets could exacerbate PH., Hypothesis: Dogs with PH will exhibit a hypercoagulable state, characterized by increased platelet activation, platelet-leukocyte, and platelet-neutrophil aggregate formation., Animals: Eleven dogs (≥3.5 kg) diagnosed with MMVD and PH and 10 dogs with MMVD lacking PH., Methods: Prospective cohort ex vivo study. All dogs underwent echocardiographic examination, CBC, 3-view thoracic radiographs, and heartworm antigen testing. Severity of PH and MMVD were assessed by echocardiography. Viscoelastic monitoring of coagulation was assessed using thromboelastography (TEG). Platelet activation and platelet-leukocyte/platelet-neutrophil interactions were assessed using flow cytometry. Plasma serotonin concentrations were measured by ELISA., Results: Unstimulated platelets from dogs with MMVD and PH expressed more surface P-selectin than MMVD controls (P = .03). Platelets from dogs with MMVD and PH had persistent activation in response to agonists. The number of platelet-leukocyte aggregates was higher in dogs with MMVD and PH compared with MMVD controls (P = .01). Ex vivo stimulation of whole blood resulted in higher numbers of platelet-neutrophil aggregates in dogs with MMVD and PH (P = .01). Assessment of hypercoagulability based on TEG or plasma serotonin concentrations did not differ between groups., Conclusion and Clinical Importance: Platelet hyperresponsiveness and increased platelet-neutrophil interaction occur in dogs with MMVD and PH, suggesting that platelets play a role of in the pathogenesis of PH. Clinical benefits of antiplatelet drugs in dogs with MMVD and PH require further investigation., (© 2024 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals LLC on behalf of American College of Veterinary Internal Medicine.)

Background: Enhanced platelet responses have been demonstrated in heartworm-infected (HWI) dogs; however, the cause and clinical implications of altered platelet function have not been fully elucidated., Objective: This study evaluated platelet function in HWI dogs., Methods: Anticoagulated whole blood collected from eight HWI and eight uninfected dogs was evaluated using turbidometric platelet aggregometry, a platelet function analyzer (PFA-100), a total thrombus analysis system (T-TAS), tissue factor-activated and tissue plasminogen activator modified thromboelastography (TF- and tPA-TEG), CBC, von Willebrand Factor activity, and fibrinogen concentrations. Platelet activation state and the presence of reticulated platelets were assessed via flow cytometric expression of P-selection (CD-62P) and thiazole orange staining., Results: Platelet aggregation responses to adenosine diphosphate (ADP, 10 μM) or collagen (20 μg/mL), PFA-100 closure times, and T-TAS occlusion times did not differ between groups. TEG values TF-R, tPA-R, TF-K, and TF-LY60 were decreased (P = .025, P = .047, P  = .038, P  = .025) and TF-MA, tPA-MA, TF-G, tPA-G and TF-alpha angle were increased (P  < .04) in HWI dogs. HWI dogs had higher fibrinogen concentrations (465.6 ± 161 mg/dL vs 284.5 ± 38 mg/dL, P  = .008) and eosinophil counts (0.686 ± 0.27 × 10 3 /μL vs 0.267 ± 0.20 × 10 3 /μL, P  = .003). There was no difference in hematocrit, activation state, or percent of reticulated platelets. Non-activated reticulated platelets exhibited higher CD62P expression compared with mature platelets., Conclusions: Chronic canine heartworm disease was accompanied by hypercoagulability, hyperfibrinogenemia, and decreased fibrinolysis. Enhanced platelet activation was not identified in this group of HWI dogs., (© 2024 The Authors. Veterinary Clinical Pathology published by Wiley Periodicals LLC on behalf of American Society for Veterinary Clinical Pathology.)

Thromboelastography (TEG) is a hemostatic assay evaluating clot initiation time, kinetics, strength, and extent of fibrinolysis. Hemostatic assays in nonmammalian species have been less extensively studied because of lack of taxon-specific reagents and unique physiology. Hemostatic or hemorrhagic disease has been described postmortem in elasmobranchs, but antemortem detection of coagulopathies is limited in this taxon. The study aimed to establish an elasmobranch TEG protocol to improve hemostatic evaluation and facilitate advanced treatment options for animals under human care. Multiple clotting initiators were assessed for efficacy with frozen-thawed citrated plasma, fresh citrated plasma, and fresh whole citrated blood: RapidTEG TM , citrated kaolin, Reptilase ® , and species brain-derived thromboplastin prepared by two different methods. Initial evaluation found plasma samples clot inconsistently, but TEG analyses using fresh whole blood consistently led to measurable TEG reactions using multiple clotting initiators. The most reliable elasmobranch TEG results were observed using citrated fresh whole blood and the RapidTEG clot initiation reagent.

Despite their low morbidity, thromboembolic events in hyperadrenocorticism are associated with high mortality. Identifying the main hemostatic abnormalities will improve the prophylactic approach of these canine patients. The aim of this study was to evaluate hemostatic alterations related with ACTH-dependent HAC and its association with hypercoagulable state. For this purpose, 25 dogs diagnosed with ACTH-dependent HAC were compared with 28 healthy dogs as a control group. The hemostatic variables included platelet count, antithrombin, fibrinogen, D-dimer, PT, aPTT, rotational thromboelastometry (ROTEM) and platelet aggregation. Results showed a hypercoagulable state in 32% (8/25) dogs by ROTEM, which had at least 2 of the next features: decreased coagulation time (CT) or clot formation time (CFT) on INTEM (5/25) or EXTEM (4/25); increased maximum clot firmness (MCF) on INTEM (9/25), EXTEM (6/25) and FIBTEM (9/25). These same variables had a significant difference (P≤ 0.05) compared with the control group, as well as the parameters of α-angle and CT. Median fibrinogen levels (310 vs.178 mg/dL), mean platelet aggregation (11.1 vs. 7.9 Ohms), median platelet count (360 vs. 225 ×10 3 /µL) and mean antithrombin activity (140 vs. 119%) were increased in ACTH-dependent HAC dogs compared to control group. PT (7.1 vs. 8.0 seconds) and aPTT (11.6 vs. 15.2 seconds) were also shortened in ACTH-dependent HAC dogs. Our findings confirm the presence of a hypercoagulable tendency in dogs with HAC. Although multifactorial, fibrinogen concentration and MCF FIBTEM showed the relevance of this protein for hypercoagulability in HAC., Competing Interests: Declaration of Competing Interest None of the authors has any other financial or personal relationships that could inappropriately influence or bias the content of the paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Objective: To determine if Irish Wolfhounds (IWs), like other sighthounds, are hyperfibrinolytic compared with nonsighthound dogs using 2 native and tissue plasminogen activator (tPA)-enhanced viscoelastic assays, one that is whole blood-based (viscoelastic coagulation monitor [VCM]) and the other that is plasma-based thromboelastography (TEG)., Design: Cohort study., Setting: University teaching hospital., Animals: A convenience sample of 27 IWs recruited from the Irish Wolfhound Association of New England Specialty and the local community, and 27 healthy, age-matched, large-breed control dogs., Interventions: None., Measurements and Main Results: Blood samples including CBC, biochemistry, traditional coagulation, and viscoelastic testing were collected from IWs and control dogs. Twelve IWs had viscoelastic testing. IWs had lower fibrinogen concentrations (215.5 ± 57.8 vs 251.4 ± 64.5 mg/dL, P = 0.034) and formed weaker clots on both whole-blood VCM and plasma TEG assays (maximum clot firmness [VCM-MCF] = 39.4 [25.1-48.8] vs 48.5 [34.6-57.3], P = 0.0042; maximum amplitude [TEG-MA] = 22.7 [14.7-33.6] vs 32.2 [26.9-42.0], P < 0.0001). IWs were hyperfibrinolytic compared with control dogs on VCM whole-blood assays, with 25 U/mL tPA (lysis at 30 min [VCM-LI30] = 68.1 [0-100] vs\ 99.9 [63.3-100], P = 0.0009; lysis at 45 min [VCM-LI45] = 31.0 [0-100] vs 98.1 [38.4-100], P = 0.0002) but hypofibrinolytic compared with controls on TEG plasma assays with 50 U/mL tPA (lysis at 30 min [TEG-LY30] = 45.7 [4.6-94.6] vs 93.7 [12.3-96.5], P = 0.0004; lysis at 60 min [TEG-LY60] = 68.7 [29.7-96.8] vs 95.7 [34.4-97.6], P = 0.0003). Minimal fibrinolysis was measured on whole-blood VCM or plasma TEG assays without the addition of tPA, and there were no differences between the 2 groups., Conclusions: Weaker clots were found in IWs than control dogs. With the addition of tPA, IWs had evidence of hyperfibrinolysis on whole-blood VCM assays and hypofibrinolysis on plasma TEG assays compared with control dogs. Without the addition of tPA, however, both groups of dogs showed minimal fibrinolysis on viscoelastic testing., (© Veterinary Emergency and Critical Care Society 2024.)

Background: Thromboelastometry (TEM) provides a comprehensive overview of the entire coagulation process and has not been evaluated in heatstroke-induced coagulopathies in dogs., Objectives: To determine the diagnostic and prognostic utility of TEM in dogs with heatstroke., Animals: Forty-two client-owned dogs with heatstroke., Methods: Prospective observational study. Blood samples for intrinsic and extrinsic TEM (INTEM and EXTEM, respectively) were collected at presentation and every 12 to 24 hours for 48 hours. Coagulation phenotype (hypo-, normo-, or hypercoagulable) was defined based on TEM area under the 1st derivative curve (AUC)., Results: Case fatality rate was 31%. Median TEM variables associated with death (P < .05 for all) included longer INTEM clotting time, lower AUC at presentation and at 12 to 24 hours postpresentation (PP), lower INTEM alpha angle, maximum clot firmness, and maximum lysis (ML) at 12 to 24 hours PP, and lower EXTEM ML at 12 to 24 hours PP. Most dogs were normo-coagulable on presentation (66% and 63% on EXTEM and INTEM, respectively), but hypo-coagulable 12 to 24 PP (63% for both EXTEM and INTEM). A hypo-coagulable INTEM phenotype was more frequent at presentation and 12 to 24 PP among nonsurvivors compared to survivors (55% vs 15% and 100% vs 50%, P = .045 and .026, respectively). AKI was more frequent (P = .015) in dogs with hypo-coagulable INTEM tracings at 12 to 24 hours. Disseminated intravascular coagulation was more frequent (P < .05) in dogs with a hypo-coagulable INTEM phenotype and in nonsurvivors at all timepoints., Conclusions and Clinical Relevance: Hypocoagulability, based on INTEM AUC, is predictive of worse prognosis and occurrence of secondary complications., (© 2024 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals LLC on behalf of American College of Veterinary Internal Medicine.)

Background: Hyperthyroidism in humans is associated with a hypercoagulable state and an increased risk of thromboembolism., Objective: To evaluate hemostatic variables in hyperthyroid and euthyroid cats with the hypothesis that hyperthyroid cats will have evidence of altered hemostasis consistent with a potential hypercoagulable state., Animals: Client-owned hyperthyroid (n = 16) and euthyroid (n = 15) cats over 8 years of age., Methods: Prospective observational study. Hyperthyroid and euthyroid cats were enrolled. Rotational thromboelastometry (ROTEM), whole-blood platelet impedance aggregometry (WBPIA) and a point-of-care viscoelastic coagulation monitor (VCM-Vet) were performed immediately after minimally traumatic venipuncture under sedation., Results: Hyperthyroid cats had significantly higher values for variables as assessed by VCM-Vet: A10 (34 [17-47] vs 25 [17-38], P = .003); A20 (39.5 [23-55] vs 31 [21-45], P = .003); and MCF (41 [24-58] vs 35 [22-49], P = .03). Hyperthyroid cats had significantly different values versus the euthyroid cohort as assessed by different ROTEM channels: increased A10, INTEM (61.5 [39-75] vs 54 [23-66], P = .007) and FIBTEM (18 [10-35] vs 13 [2-27], P = .01); increased A20, INTEM (68 [45-78] vs 61 [30-70], P = .006) and FIBTEM (17 [10-34] vs 11 [2-25], P = .002); increased MCF, EXTEM (72 [65-81] vs 69 [34-78], P = .04), INTEM (70 [45-85] vs 62 [35-71], P = .01) and FIBTEM (18 [13-37] vs 14 [3-27], P = .02); increased alpha angle, EXTEM (80 [68-85] vs 76 [41-84], P = .01); shortened CT, EXTEM (52.5 [29-73] vs 60 [52-92], P = .003) and FIBTEM (52.5 [16-75] vs 65 [53-165], P = .001); and decreased ML, FIBTEM (20 [1-36] vs 33 [19-59], P <.001). No significant differences were found with WBPIA., Conclusions and Clinical Importance: The hyperthyroid cats in this study had evidence of altered hemostasis as assessed by 2 viscoelastic methodologies, and characterized by increased clot amplitude, firmness, and faster coagulation times vs euthyroid controls., (© 2024 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals LLC on behalf of American College of Veterinary Internal Medicine.)

Sepsis/endotoxemia associates with coagulation abnormalities. We showed previously that exogenous choline treatment reversed the changes in platelet count and function as well as prevented disseminated intravascular coagulation (DIC) in endotoxemic dogs. The aim of this follow-up study was to evaluate the effect of treatment with choline or cytidine-5'-diphosphocholine (CDP-choline), a choline donor, on endotoxin-induced hemostatic alterations using thromboelastography (TEG). Dogs were randomized to six groups and received intravenously (iv) saline, choline (20 mg/kg) or CDP-choline (70 mg/kg) in the control groups, whereas endotoxin (0.1 mg/kg, iv) was used alone or in combination with choline or CDP-choline at the same doses in the treatment groups. TEG variables including R- and K-time (clot formation), maximum amplitude (MA) and α-angle (clot stability), G value (clot elasticity), and EPL, A, and LY30 (fibrinolysis), as well as overall assessment of coagulation (coagulation index - CI), were measured before and at 0.5-48 h after the treatments. TEG parameters did not change significantly in the control groups, except for CI parameter after choline administration. Endotoxemia resulted in increased R-time and A value (P < 0.05), decreased K-time (P < 0.05), α-angle (P < 0.001) and CI values (P < 0.01) at different time points. Treatment with either choline or CDP-choline attenuated or prevented completely the alterations in TEG parameters in endotoxemic dogs with CDP-choline being more effective. These results confirm and extend the effectiveness of choline or CDP-choline in endotoxemia by further demonstrating their efficacy in attenuating or preventing the altered viscoelastic properties of blood clot measured by TEG., Competing Interests: Declaration of competing interest There are no conflicts of interest., (Copyright © 2023. Published by Elsevier Ltd.)

Objective: Thromboelastography (TEG) is a whole blood assay that yields global assessment of hemostasis, as it evaluates clot time, strength, and kinematics of clot formation and lysis. The main objective was to describe preoperative TEG findings in dogs that had an adrenalectomy performed and, secondarily, to describe TEG findings in the dogs with or without hyperadrenocorticism (HAC)., Animals: 30 dogs that had preoperative TEG and adrenalectomy performed., Methods: Medical records between 2018 and 2022 were reviewed. Signalment, diagnostic data, and perioperative treatment were abstracted., Results: 53% (16/30) of the dogs were hypercoagulable, and none were hypocoagulable. Based on histopathology, 6 of 9 dogs with adenocarcinoma were hypercoagulable, 4 of 8 with pheochromocytoma were hypercoagulable, and 6 of 10 with adenoma were hypercoagulable. None of the 3 dogs with other histopathologic diagnoses or combinations of diagnoses (adrenocortical hyperplasia, poorly differentiated sarcoma, and both adrenocortical adenocarcinoma and pheochromocytoma) were hypercoagulable. Of the 14 dogs tested preoperatively for HAC, 4 of 8 HAC dogs were hypercoagulable and 2 of 6 non-HAC dogs were hypercoagulable., Clinical Relevance: The present report describes for the first time TEG findings for dogs undergoing adrenalectomy and suggests that the majority of dogs with adrenal neoplasia are hypercoagulable based on TEG results.

Background: Cerebrovascular accidents (CVAs) in dogs are diagnosed using magnetic resonance imaging (MRI). This modality is sometimes unavailable, and CVAs can resemble other lesions on MRI. D-dimer concentration and thromboelastography (TEG) are utilized in human medicine in addition to diagnostic imaging to support diagnosis of CVAs, but their use in veterinary patients has not been assessed., Objective: Assess utility of blood D-dimer concentration and TEG in supporting the imaging diagnosis of CVAs in dogs., Animals: Sixty-eight client-owned dogs with neurologic signs that had brain MRI and D-dimer concentration or TEG performed., Methods: Multicenter, retrospective study. The incidence of abnormal D-dimer concentration or TEG was compared between patients with MRI evidence of CVA and a control population. Analysis methods included Fisher's exact test or Chi-squared test for association and comparison of independent proportions., Results: Neither D-dimer concentration nor TEG was significantly associated with a CVA (P = .38 and .2, respectively). D-dimer testing was performed in a low-risk population and showed low sensitivity (30.8%; 95% confidence interval [CI], 10%-61%) and high specificity (86.4%; 95% CI, 64%-96%) for CVA diagnosis. Thromboelastography was performed in a high-risk population and showed moderate sensitivity (64.3%; 95% CI, 44%-81%) and specificity (66.7%; 95% CI, 24%-94%) for CVA diagnosis. Abnormal D-dimer concentration or TEG were not helpful in differentiating hemorrhagic from ischemic stroke (P = .43 and .41, respectively)., Conclusions: Although blood D-dimer concentration or TEG alone are not diagnostic of CVAs in dogs, a positive D-dimer result supports additional testing for CVA., (© 2024 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals LLC on behalf of American College of Veterinary Internal Medicine.)

Background: No treatment other than platelet administration is known to protect against spontaneous hemorrhage in thrombocytopenic dogs., Objectives: Primary: determine if treatment with ε-aminocaproic acid (EACA) decreases the requirement for blood transfusions and improves outcome in dogs with severe thrombocytopenia. Secondary: find evidence of hyperfibrinolysis and determine the effect EACA administration on rapid (rTEG) and tissue plasminogen activator-spiked (tPA-rTEG) thromboelastography parameters., Animals: Twenty-seven dogs with severe thrombocytopenia were treated with EACA, and data from an additional 33 were obtained from the hospital database as historical control (HC) cohort., Methods: Single arm clinical trial with HCs. The EACA group dogs received EACA (100 mg/kg IV followed by a constant-rate infusion [CRI] of 400 mg/kg/24 hours). Thromboelastography before and during EACA infusion, hospitalization days, number of transfusions, and mortality were compared., Results: No difference was found in number of transfusions per dog (median, interquartile range; 1, 0-2.5 vs 0.9, 0-2; P = .5) and hospitalization days (4, 4-6 vs 4.5, 3.75-6; P = .83) between HC and EACA groups, respectively, and no difference in survival was identified by log-rank analysis (P = .15). Maximum amplitude on both rTEG and tPA-rTEG increased after EACA administration (rTEG baseline: 23.6, 9.6-38.9; post-EACA: 27.3, 19.8-43.2; P < .001; tPA-rTEG baseline: 23, 10.9-37.2; post-EACA: 24.7, 16.7-44.8; P < .002)., Conclusions and Clinical Importance: Although EACA increased clot strength, there was no effect on outcome. Treatment with EACA at this dosage cannot be recommended as a routine treatment but may be considered for dogs with severe ongoing hemorrhage., (© 2024 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals LLC on behalf of American College of Veterinary Internal Medicine.)

Elephant endotheliotropic herpesvirus (EEHV) can induce fatal hemorrhagic disease (HD) in African elephants ( Loxodonta africana ). Once clinical signs develop, progression is rapid, even with aggressive treatment. There is a critical need to develop point-of-care diagnostic tests to aid in identification of EEHV-HD prior to the onset of overt clinical signs. Study objectives were to investigate a novel, point-of-care viscoelastic coagulation monitor (VCM Vet), compare the results to thromboelastography (TEG), and report traditional hemostatic analytes in adult African elephants. Whole blood was collected from seven clinically healthy elephants (four females and three males, 18-47 yr) and analyzed in duplicate via VCM Vet and kaolin-activated TEG 1-3 and 30 min following collection, respectively. Separated plasma was frozen for ancillary coagulation testing. Both analyses generated quantifiable clotting reactions with variables (median [range]) describing clot formation rate (VCM Vet, clot time = 682 s [530-987 s], clot formation time = 244 s [186-744 s], Alpha = 40° [14-47°]; TEG, reaction time = 6.2 min [3.7-11.8 min], kinetic time = 1.3 min [0.9-2.6 min], Alpha = 70° [57-77°]), clot strength (VCM Vet, maximum clot formation = 34 units [20-45 units]; TEG, maximum amplitude = 75 mm [69-80 mm], shear elastic modulus strength = 14.7 Kdynes/s [11.3-19.5 Kdynes/s]), and clot lysis (VCM Vet, lysis index at 30 min = 100% [100-99%], lysis index at 45 min = 98% [95-100%]; TEG, lysis index at 30 min = 0% [0-0.4%], lysis index at 60 min = 1.4% [0-2.6%]) recorded. Additional testing (median [range]) included D-dimer concentration (33 ng/ml [28-94 ng/ml]), prothrombin time (12.4 s [12.2-13.2 s]), activated partial thromboplastin time (17.2 s [14.2-18.8 s]), and fibrinogen concentration (297 [282-383] mg/dL). Tracings generated by VCM Vet and TEG were clinically similar, and there was visual agreement and minimal difference between quantitative variables for duplicate tests. VCM Vet is a promising, user-friendly tool for use in identification and management of coagulopathies in African elephants.

Objectives: To determine platelet function and assess fibrinolysis in dogs following trauma using multiple electrical impedance aggregometry and a modified thromboelastographic (TEG) technique. To determine if the severity of trauma, as assessed by the Animal Trauma Triage (ATT) score and clinicopathological markers of shock, is associated with a greater degree of platelet dysfunction and fibrinolysis., Setting: University teaching hospital., Animals: Twenty client-owned dogs with trauma (occurring <24 h prior to admission and blood sampling) and ATT score of >4 were prospectively recruited. A control group of 10 healthy dogs was included., Interventions: None., Measurements and Main Results: Platelet function was measured using multiple electrode platelet aggregometry (MEPA) utilizing arachidonic acid, ADP, and collagen agonists. Fibrinolysis was assessed in citrated whole blood with the addition of tissue plasminogen activator (tPA; 50 U/mL) using kaolin-activated TEG. Conventional statistical analysis was performed to compare coagulation parameters between the groups and assess linear correlations. Median (interquartile range) ATT score was 5 (5-7), and 65% (n = 13) of dogs suffered polytrauma. Mean (± SD) time from trauma to blood sampling was 9 hours (± 6). Median (interquartile range) shock index and plasma lactate concentration were 1.1 (0.7-2.0, n = 16) and 2.9 mmol/L (0.9-16.0, n = 18), respectively. Four dogs did not survive to discharge (20%). There were no differences between the trauma and control group coagulation variables. A moderate negative correlation between ATT score and area under the curve for ADP was found (P = 0.043, r 2  = -0.496)., Conclusions: Preliminary evaluation of platelet function measured by MEPA, and fibrinolysis measured by tPA-modified TEG, is not significantly different in this population of dogs with traumatic injury compared to healthy dogs., (© 2023 The Authors. Journal of Veterinary Emergency and Critical Care published by Wiley Periodicals LLC on behalf of Veterinary Emergency and Critical Care Society.)

Background: The most common haemostatic abnormality in dogs with cancer is hypercoagulability. A transient hypercoagulability has been documented in people with hepatocellular carcinoma (HCC) that resolves within weeks following hepatic tumour resection., Objective: The objective was to compare the haemostatic status of dogs with liver tumours and healthy control dogs, by comparing coagulation and thromboelastography (TEG) measurements at three time points., Methods: Liver tumour and healthy control dogs receiving surgery for liver lobectomy and ovariohysterectomy, respectively, were prospectively enrolled. All dogs had blood collected at three time points: pre-operative, 24 h post-operative and ~2 weeks post-operative. Haematological and haemostatic values were compared across time points in each group using repeated measures ANOVA tests., Results: Ten and eight dogs were enrolled for the liver and control groups, respectively. Platelet count was significantly higher in the liver group than the control group at all time points, but within the normal range (pre-operative: 438.7 vs. 300.9 × 10 9 /L, p = .0078; 24 h post-operative: 416.2 vs. 283.9 × 10 9 /L, p = .0123; 10-14 days post-operative: 524.6 vs. 317.3 × 10 9 /L, p = .0072). The measure of the overall coagulant state (G-value) was significantly increased for the liver group compared to the control group at all time points (pre-operative: 15.6 vs. 8.6 d/sc, p = .0003; 24 h post-operative: 18.3 vs. 11.2 d/sc, p = .039; 10-14 days post-operative: 15.1 vs. 9.6 d/sc, p = .015)., Conclusion: The liver group was hypercoagulable based on elevated G-values at all time points compared to the control group. This hypercoagulability was attributed to the effect of hepatic tumours alone, and not secondary to surgery and anaesthesia., (© 2023 The Authors. Veterinary and Comparative Oncology published by John Wiley & Sons Ltd.)

The objective of this study was to investigate the effect of etamsylate on canine blood and heparinised canine blood from healthy dogs using thromboelastography (TEG). Citrated blood was obtained from twenty healthy client-owned dogs, and 3 experiments were performed. Experiment 1 compared TEG in blood versus blood with etamsylate (250 mM). Experiment 2 evaluated TEG in heparinised blood (1 U/mL) with and without the addition of etamsylate (250 mM). Experiment 3 evaluated dose escalation of etamsylate (control, 250 μM, 500 μM and 1000 μM) in heparinised blood (1 U/mL). The addition of etamsylate to canine blood in experiment 1 increased the percentage of clot lysis at 30 min (z = -2.103, p  = .035) and 60 min (z = -1.988, p  = .047), suggesting that etamsylate could have a fibrinolytic effect. When etamsylate was added to heparinised canine blood (1 U/mL), etamsylate produced a dose-dependent inhibition of the effect of heparin when higher concentrations of etamsylate were used (500 μM and 1000 μM). The linear mixed effects model showed significant increases in α angle and maximal amplitude when high dose etamsylate was added compared to the control. In conclusion, etamsylate could be used at higher doses to inhibit the effect of heparin in dogs when protamine might not be available. However, etamsylate might have a fibrinolytic effect when used in healthy dogs.

The objective of this study was to investigate the thromboelastography (TEG) variables and platelet count after Asian pit viper (Gloydius) envenomation in dogs compared with healthy control dogs. Ten dogs with snake envenomation and twenty healthy dogs were included. There was a significant decrease in G (P=0.017), maximum amplitude (MA) (P=0.012), angle value (P=0.041), platelet count (P<0.001, as well as an increase in K value (P=0.034) and R value (P=0.007) in dogs with snake envenomation. The results of this study revealed that dogs with Asian pit viper (Gloydius) envenomation showed a hypocoagulable state compared with healthy dogs. Our findings may support the use of TEG for diagnosing and monitoring coagulopathy after Asian pit viper (Gloydius) envenomation in dogs.

Objective: To describe hemostatic derangements associated with canine anaphylaxis and to assess for association with syndrome severity., Design: Prospective observational study., Setting: University teaching hospital., Animals: Twenty-seven client-owned dogs, recruited from November 2018 to January 2022, diagnosed with anaphylaxis of varying severity were included. Study inclusion required presentation <6 hours after initiation of clinical signs, no medications or history of illness within the prior 2 weeks, lack of comorbidities expected to affect hemostasis, and lack of a disease state that could alternatively explain the clinical presentation., Interventions: Blood samples were collected within the first hour of presentation for CBC, serum biochemistry, prothrombin time (PT), activated partial thromboplastin time (aPTT), and viscoelastic coagulation testing for use with a cartridge-based point-of-care device., Measurements and Main Results: Clotting time and clot formation time were prolonged, alpha angle and maximum clot firmness were decreased, PT and aPTT were prolonged, and platelet counts were lower in severe cases compared to mild and moderate cases. There were no differences for any parameter between mild and moderate cases. The presence or absence of abdominal effusion was not associated with hemostatic status., Conclusions: Global hemostatic derangements consistent with hypocoagulability are a prominent feature of severe anaphylaxis in dogs and should be considered for routine evaluation., (© 2023 The Authors. Journal of Veterinary Emergency and Critical Care published by Wiley Periodicals LLC on behalf of Veterinary Emergency and Critical Care Society.)

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., (© Veterinary Emergency and Critical Care Society 2023.)

Background: Viscoelastic coagulation monitor (VCM-Vet) is a point-of-care device that has been used to characterize hemostatic abnormalities in sick pets but has not been validated in veterinary patients., Objectives: We aimed to compare VCM-Vet and thromboelastography (TEG) in sick dogs with suspected disorders of hemostasis., Methods: Duplicate VCM-Vet tests using untreated native blood performed concurrently on two VCM-Vet machines, and simultaneous TEG tests were performed (one citrated native (CN), and one activated with tissue factor (TF) at a 1:3600 dilution). Each VCM-Vet result was compared with both TF-activated and CN TEG., Results: Fifty-three dogs were enrolled. Eleven cases displayed apparent hyperfibrinolysis. Spearman correlation coefficients for individual VCM-Vet devices and CN and TF TEG were obtained between R and CT values and ranged from 0.21 to 0.27, CFT and K (r = 0.60-0.67), angles (r = 0.51-0.62), and MCF and MA (r = 0.85-0.87). Comparison of the two VCM-Vet devices displayed positive correlations for all clot formation parameters with Lin's concordance correlation coefficients of 0.75-0.95. Variable lysis parameter agreement existed between the VCM-Vet devices and VCM-Vet and TEG. When samples were classified as hypercoagulable or coagulopathic, VCM-Vet had a low positive predictive value (17-33%) for the detection of hypercoagulable states and a moderate negative predictive value (64-74%) for the detection of coagulopathy as defined by TEG., Conclusions: VCM-Vet and TEG had variable correlations in clot formation values and a strong correlation for final clot strength. More information is needed to make conclusions about the lysis parameters. Artifact in the fibrinolysis portion of the test can confound the interpretation of VCM-Vet results., (© 2023 American Society for Veterinary Clinical Pathology.)

Objectives: Determine the effect of sample holding time and single sample reuse on viscoelastic coagulation parameters when using fresh equine native whole blood., Animals: 8 healthy adult horses from a university teaching herd., Procedures: Blood collected by direct jugular venipuncture (18 ga needle, 3 mL syringe) was held at 37 °C for 2, 4, 6, or 8 minutes according to 1 of 2 protocols. Syringes were gently inverted twice, a small amount of blood was expressed, testing cartridges were filled, and placed within the VCM-Vet™ device (Entegrion Inc). Protocol A: samples were processed from a single syringe. Protocol B: 4 syringes were drawn through a single needle. VCM-Vet™ measures assessed included clot time (CT), clot formation time (CFT), alpha angle (AA), amplitude at 10/20 minutes (A10/A20), maximal clot firmness (MCF), and lysis index at 30/45 minutes (LI30/LI45). Differences over time were examined using the Friedman test and post hoc Wilcoxon Rank Sum Test with Bonferroni correction, P ≤ .05., Results: Following Protocol A, there was a significant effect of holding time for CT (P = .02), CFT (P = .04), and AA (P = .05). CT and AA decreased over time, while CFT increased. Samples handled by Protocol B showed no significant difference over time for any of the VCM-Vet™ parameters., Clinical Relevance: Sample holding time and handling protocol impact VCM-Vet™ testing results of fresh equine native whole blood. Viscoelastic coagulation samples tested using the VCM-Vet™ may be held unagitated for up to 8 minutes after collection while warm, but should not be reused.

Objective: To estimate the point prevalence and duration of hyperfibrinolysis (HF) in dogs undergoing surgical control of spontaneous hemoperitoneum (SHP)., Design: Prospective observational study., Setting: Single veterinary teaching hospital., Animals: Forty-five client-owned dogs with SHP were screened for HF. Eighteen HF dogs treated surgically were studied., Interventions: None., Measurements and Main Results: Dogs with SHP and evidence of shock admitted for surgical control of hemorrhage were screened for HF. Blood samples were collected for PCV, total plasma protein, platelet count, and thromboelastography with 50 U/mL of tissue plasminogen activator at presentation and every 8 hours postoperatively until 72 hours, discharge, or death. HF was defined as a tissue plasminogen activator-activated thromboelastography lysis percentage measured 30 minutes after maximum amplitude (LY30) of ≥20%. LY30 values were compared to a cohort of samples obtained from healthy dogs (n = 22). The point prevalence of HF in all dogs screened was 40% (18/45 dogs), and the mean LY30 at baseline for HF dogs was 48.9% (±24.2%), which was significantly higher than that of control dogs (4.8% ± 7.1%, P < 0.001) and non-HF dogs (1.9% ± 5.7%, P < 0.001). In HF dogs, there was a significant decrease in LY30 between baseline and 8 hours (P < 0.0001) and between 8 and 16 hours (P = 0.035) but no significant change thereafter. LY30 at 8 hours (4%, range: 0%-23.4%) was not statistically different from control dogs (6.5%, range: 1.2%-32.8%, P = 0.664) suggesting early resolution of HF in this population. Only 2 of 18 dogs were persistently hyperfibrinolytic at 24 hours. Malignancy was diagnosed in 12 of 18 dogs (66.6%), while a benign etiology occurred in 6 of 18 dogs (33.3%). All HF dogs survived to discharge., Conclusions: HF occurs in some dogs with hypovolemic shock due to hemoperitoneum but resolves rapidly following surgical control of bleeding without antifibrinolytic medications. Routine postoperative use of antifibrinolytics in dogs with hemoperitoneum in dogs undergoing surgical control of bleeding may not be warranted., (© Veterinary Emergency and Critical Care Society 2023.)

Background: Sudden acquired retinal degeneration syndrome (SARDS) is a common cause of irreversible blindness in dogs. It bears clinical resemblance to hypercortisolism, which can be associated with hypercoagulability. The role of hypercoagulability in dogs with SARDS is unknown., Objective: Determine hemostatic profiles in dogs with SARDS., Animals: Prospective pilot study: Dogs with a history of SARDS (n = 12). Prospective case-control study: Dogs with recent onset of SARDS (n = 7) and age-, breed-, and sex-matched controls (n = 7)., Methods: Prospective pilot study: We performed thromboelastography (TEG). Prospective case-control study: Dogs had CBC, serum biochemistry, urinalysis, TEG, fibrinogen concentration, antithrombin activity, D-dimers, thrombin-antithrombin complexes, and optical platelet aggregometry performed., Results: Prospective pilot study: 9/12 dogs with a history of SARDS were hypercoagulable with increased TEG G value and 2/3 had hyperfibrinogenemia. Case-control study: All dogs with SARDS and 5/7 controls were hypercoagulable based on TEG G value. Dogs with SARDS had significantly higher G values (median, 12.7 kdynes/s; range, 11.2-25.4; P = .04) and plasma fibrinogen concentration (median, 463 mg/dL; range, 391-680; P < .001) compared to controls., Conclusions and Clinical Importance: Hypercoagulability was common in both dogs with SARDS and controls, but dogs with SARDS were significantly more hypercoagulable on TEG. The role of hypercoagulability in the pathogenesis of SARDS remains to be determined., (© 2023 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals LLC on behalf of American College of Veterinary Internal Medicine.)

The transfusion of stored platelets has emerged as an efficient method for treating dogs with thrombocytopenia. However, the availability of fresh platelets is limited in veterinary medicine due to demanding storage conditions. Lyophilized platelets have long shelf lives and can be easily stored, increasing their accessibility for thrombocytopenic dogs. Due to the lack of research and information on the dose effect, canine lyophilized platelets are used at a clinical dosage without research-based evidence. This study was to evaluate the dose effect of lyophilized canine platelets on blood coagulability. Three different concentrations of lyophilized canine platelets were added to in vitro hemodilution blood model, increasing the platelet count by 25, 50, and 100 × 10 6 /ml and coagulation profiles were analyzed. The coagulability was evaluated via the plasma fibrinogen concentration, coagulation time, thromboelastography (TEG), and platelet function analyzer (PFA). Higher concentrations of lyophilized platelets showed dose-dependent association with decreased aPTT and R-time of TEG and increased alpha angle and MA of TEG. These results showed the potential that the higher dose of canine lyophilized platelets better improve blood coagulability than the standard dose and provided the basis for further safety and clinical studies., (© 2023. The Author(s).)

Objective: To compare viscoelastic parameters between healthy control dogs and dogs with primary immune-mediated hemolytic anemia (pIMHA) using a new, point-of-care viscoelastic coagulation monitor (VCM). a DESIGN: Retrospective study from 2017 to 2021., Setting: Three regional private referral centers., Animals: Eighteen client-owned dogs with pIMHA and 33 healthy control dogs. pIMHA dogs were defined based on established criteria., Interventions: None., Measurements and Main Results: Medical records of dogs with pIMHA and VCM performed at diagnosis from 2017 to 2021 and apparently healthy control dogs voluntarily enrolled in the blood donor program from 2017 to 2018 were reviewed. For the healthy control dogs, consent was obtained to perform VCM in addition to traditional screening. Compared to healthy control dogs, dogs with pIMHA had mean VCM parameters consistent with hypercoagulability, demonstrated by lower mean (SD) clot formation time (108 s [30] vs 233 s [55]; P < 0.0001), higher mean alpha angle (62 degrees [6] vs 52 degrees [6]; P < 0.0001), higher mean maximum clot formation (49 VCM units [11] vs 32 VCM units [5]; P < 0.0001), higher mean amplitude at 10 minutes (40 VCM units [11] vs 19 VCM units [3]; P < 0.0001), and higher mean amplitude at 20 minutes (47 VCM units [11] vs 25 VCM units [4]; P < 0.0001). pIMHA dogs also had significantly higher median (interquartile range) lysis index at 30 minutes (100% [100-100] vs 98% [90-100]; P < 0.0001). When compared to 3 established normal canine reference intervals, dogs with pIMHA had a significantly higher proportion of VCM variables (48%-57%) consistent with hypercoagulability, and a significant percentage of pIMHA dogs (78%-89%) had VCM tracings consistent with hypercoagulability overall, irrespective of the interval utilized for interpretation., Conclusions: This study demonstrates hypercoagulability in dogs with pIMHA when compared to healthy control dogs using VCM. Prospective evaluation is warranted to further characterize these findings as well as to evaluate their clinical impact., (© Veterinary Emergency and Critical Care Society 2022.)

The viscoelastic coagulation monitor (VCM) is described as a point-of-care analyzer relying on activation of fresh whole blood (FWB) via contact between 2 glass plates. Kaolin is used as an activator in thromboelastography to reduce variability and shorten clotting times. The goal of this study was to compare VCM results from kaolin-activated, recalcified citrated samples with that from FWB. The VCM testing was performed using FWB and kaolin-activated, recalcified citrated samples. The VCM results were recorded for clot time (CT; seconds), clot formation time (CFT; seconds), alpha (degree), amplitude at 10 and 20 minutes (A10 and A20; VCM units), maximum clot firmness (MCF; VCM units), and lysis index (LI; %). Values were compared using a t- test or Wilcoxon-Mann-Whitney test, with a P- value < 0.05 considered significant. Variability between samples was calculated using Levene's test. The VCM kaolin activation resulted in significantly faster CT and CFT ( P < 0.0001), higher alpha angle ( P < 0.001), and higher A10 and A20 ( P = 0.007, P = 0.015) compared to FWB. There was no difference in MCF, LI30, or LI45. There was no difference in variability identified. The addition of kaolin to recalcified citrated whole blood VCM samples results in more rapid clotting of FWB alone and could be considered for clinical use in dogs., (Copyright and/or publishing rights held by the Canadian Veterinary Medical Association.)

Background: The viscoelastic coagulation monitor (VCM Vet) is a novel, portable device that provides a global assessment of hemostasis. The study aims were to evaluate serial viscoelastic analysis during the perianesthetic period in healthy dogs and to compare the agreement between two VCM Vet devices. Twenty healthy dogs undergoing orthopedic surgery were enrolled. Whole blood samples were collected from an intravenous catheter at four time points: baseline, 15 min after premedication, 60 min after inhalant initiation, and 60 min after inhalant termination. Viscoelastic tests were performed in duplicate on different devices, providing: clot time (CT; seconds), clot formation time (CFT; seconds), alpha angle (α; degrees), amplitude (units) at 10 (A10) and 20 (A20) minutes post clot time, maximum clot firmness (MCF; units), and lysis index (%) at 30 (Li30) and 45 (Li45) minutes post maximum clot formation., Results: One hundred sixty samples were analyzed. The speed of CT and CFT significantly decreased an average of 25.5 s (95% confidence interval [CI]15.9-35.0) and 6.9 s (95% CI 3.1-10.7) per time point, respectively. There were no significant changes in clot strength or lysis variables. The Bland-Altman style plot shows an acceptable rate of agreement for all variables with intra-class correlation ranging from 0.64-0.94., Conclusion: The rate of clot formation (CT and CFT) decreased over the perianesthetic period in healthy dogs undergoing surgery. These changes were small and occurred without changes in clot strength or fibrinolysis rate, thus were not clinically relevant. There was clinically acceptable consistency between devices., (© 2022. The Author(s).)

Most dogs with immune mediated haemolytic anaemia (IMHA) are hypercoagulable, as measured by thromboelastography (TEG). Thromboelastography-platelet mapping (TEG-PM) has been used to assess platelet function in human patients treated with aspirin or clopidogrel. The aim of this study was to compare platelet thromboxane A 2 -receptor inhibition (TXA 2- RI) and platelet adenosine diphosphate (ADP)-receptor inhibition (ADP-RI) as measured by TEG-PM in dogs with primary IMHA receiving aspirin or clopidogrel to determine if TEG-PM might be useful to monitor treatment. Eighteen client-owned dogs with IMHA were enroled in a prospective double blinded study. Dogs were randomised to receive aspirin or clopidogrel in addition to standard therapy. Thromboelastography was measured before, and 1 and 4 days after commencing treatment. Thromboelastography-PM was performed on days 1 and 4. Non-responders were defined as < 50 % platelet thromboxane A 2 -receptor inhibition (TXA 2- RI) in the aspirin group and < 50 % platelet adenosine diphosphate (ADP)-receptor inhibition (ADP-RI) in the clopidogrel group, on day 4. Mean platelet TXA 2 -RI and platelet ADP-RI were not significantly different between groups at any timepoint (P > 0.05). The overall mean percentage inhibition of TXA 2 -receptor was 25 % (aspirin 33 %, clopidogrel 15 %), and of ADP-receptor was 82 % (aspirin 83 %, clopidogrel 80 %). On day 4, 6/9 dogs (66 %) in the aspirin group and 2/8 dogs (25 %) in the clopidogrel group were non-responders (P = 0.086). Two dogs defined as responders based on TEG-PM developed thromboembolism. Overall, there was no significant difference in efficacy between aspirin and clopidogrel based on measurement of receptor inhibition using TEG-PM (P > 0.05), and routine TEG was not reliable for monitoring treatment response in dogs with IMHA. In some dogs, there was a discrepancy between TEG-PM results and clinical response. Further investigation of TEG-PM use in dogs, including its usefulness to monitor treatment response and adjust treatment in individual dogs and any effect of anaemia, is warranted., Competing Interests: Conflict of interest statement This study was funded by the Canine Research Foundation (CRF). The CRF played no role in the study design nor in the collection, analysis and interpretation of date, nor in the decision to submit the manuscript for publication. None of the authors have any other financial or personal relationships that could inappropriately influence or bias the content of the paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Objectives: To compare the efficacy of 2 equine-origin antivenom products on correction of coagulation abnormalities noted on thromboelastography (TEG) caused by Crotalus atrox venom in vitro., Design: Prospective in vitro controlled study., Setting: Veterinary teaching hospital., Animals: Six healthy dogs., Interventions: Blood from each dog was used for 4 separate kaolin-activated TEG analyses: A negative control (blood-saline) and positive control (blood-Crotalus atrox venom) were used to assess the dog's normal coagulation and the effect of venom on TEG parameters. Thromboelastographic analyses were then run with blood, venom, and either Argentinian or North American antivenom. All TEG analyses from each dog were compared for efficacy., Measurements and Main Results: The mean R values between the North American antivenom and negative controls were not significantly different (P = 0.681), but were significantly different (P = 0.024) between the Argentinian antivenom and negative controls. The mean fibrinolysis values measured 30 minutes after maximum amplitude achieved between the North American antivenom and negative controls were not significantly different (P = 0.198), but were significantly different (P < 0.001) between the Argentinian antivenom and negative controls. The mean K values between the Argentinian antivenom and negative controls were not significantly different (P = 0.274), but were significantly different (P = 0.043) between the North American antivenom and negative controls., Conclusions: The North American antivenom normalized time to clot formation and fibrinolysis, while the Argentinian antivenom normalized rate of clot formation. Further studies in naturally envenomated patients are necessary to determine if these in vitro results would translate into different clinical outcomes., (© Veterinary Emergency and Critical Care Society 2022.)

The TEG 6s (Haemonetics) point-of-care viscoelastic analyzer is portable, compact, simple to use, and has the potential for rapid viscoelastic analysis that can guide the treatment of veterinary patients at the site of care. Although approved for use in people, the TEG 6s has yet to be evaluated for hemostatic analysis in veterinary medicine. Citrated whole blood (CWB) was collected from 27 healthy dogs. An aliquot of CWB from each dog was diluted by 33% with an isotonic crystalloid, representing an in vitro model of hemodilution. Unaltered and diluted CWB samples were analyzed using 2 TEG 6s and 6 TEG 5000 (Haemonetics) analyzers. The 6 TEG 5000 analyzers ran duplicate analyses of either unaltered or diluted samples using 1 of 3 reagents (Haemonetics): Kaolin TEG, RapidTEG, or TEG Functional Fibrinogen. Duplicate TEG 5000 analyses were averaged and compared with a single TEG 6s analysis. Lin concordance correlation coefficient and Bland-Altman plots were used to evaluate agreement of reaction time, kinetic time, alpha angle, maximum amplitude (MA), and G value (G) for samples activated with Kaolin TEG, and agreement of MA for samples activated with RapidTEG between the 2 machines. Overall, agreement between the TEG 6s and TEG 5000 analyzers was poor. Viscoelastic measurements by the TEG 6s and TEG 5000 in healthy dogs were not all interchangeable. Agreement was satisfactory only for MA and G measurements of diluted blood samples activated with Kaolin TEG, and MA measurements for both unaltered and diluted blood samples activated with RapidTEG.

Objective: To assess the safety and efficacy of the platelet-like nanoparticle (PLN), and to assess its safety in repeated administration., Animals: 6 purpose-bred dogs., Procedures: The PLN was administered IV at 3 different doses using a randomized crossover design. Each dog received a full dose of 8 X 1010 particles/10 kg, half dose, and 10 times the dose, with a 14-day washout period between doses. Biochemical, prothrombin time, partial thromboplastin time, and fibrinogen analyses were performed at baseline and 96 hours postinfusion. A CBC, kaolin-activated thromboelastography, platelet function assay closure time, and buccal mucosal bleeding time were performed at baseline and 1, 6, 24, 48, 72, and 96 hours postinfusion., Results: No significant changes were observed over time in the thromboelastography parameters, closure time, and buccal mucosal bleeding time. After the administration of the half dose, hematocrit levels decreased significantly at 1, 6, 24, 48, and 96 hours, with all values within the reference range. The platelet count was decreased significantly at hours 1, 6, 24, 48, and 72 after administration of the half dose, with values less than the reference range at all hours but hour 72. No significant changes in serum biochemistry, coagulation panel, and fibrinogen were observed for all doses. No adverse events were noted during the first infusion. Three dogs experienced transient sedation and nausea after repeat infusion., Clinical Relevance: The PLN resulted in a dilution of hematocrit and platelets, and did not significantly alter hemostasis negatively. The safety of repeated doses should be investigated further in dogs.

Introduction: Tranexamic acid (TXA) is an antifibrinolytic drug used for the prophylaxis and treatment of haemorrhage of various origin. This retrospective study investigated the effect of TXA on ongoing bleeding in dogs with nonsurgically treated haemoabdomen. The study population consisted of 48 dogs treated in the period 2009-2020 at the Small Animal Clinic of the Vetsuisse Faculty of Zurich. Twenty-eight of 48 dogs were treated with 20 mg/kg TXA IV within 3h of diagnosis of haemoabdomen. Dogs treated with and without TXA were monitored over 48 hours for signs of ongoing haemorrhage. Ongoing haemorrhage was defined as an increase in abdominal fluid accumulation, a decrease in haematocrit of >5% over time or need for surgical exploration after at least 12 hours of medical treatment. Transfusion requirements, cumulative amount of fluid therapy, heart rate, respiratory rate, temperature, systolic and mean arterial pressure, estimate of abdominal fluid identified by FAST analysis, venous haematocrit, abdominal haematocrit, serum albumin, serum lactate and thrombocyte count were extracted from patient records at 6, 12, 24 and 48 hours after diagnosis of haemoabdomen. Groups were comparable at presentation, however dogs of the TXA group showed a significantly lower abdominal haematocrit at presentation (37 vs 45%, P=0,034) and a higher fluid accumulation (P=0,019), both persisting over time. None of the outcome parameters for ongoing haemorrhage was significantly different between groups. Transfusion requirement was low and similar in both groups. Of interest, none of the 16 dogs undergoing thromboelastometry showed hyperfibrinolysis at presentation. We conclude that other mechanisms than antifibrinolytic therapy was responsible for cessation of bleeding in the majority of patients.

Objective: To evaluate the effect of 6% hydroxyethyl starch (HES) 670/0.75 and 6% HES 130/0.4 dilution of canine whole blood on coagulation using dynamic viscoelastic coagulometry (DVC)., Animals: 56 healthy adult dogs., Procedures: 2 blood samples were obtained from each dog and randomized to 1 of 7 groups-undiluted or 2 dilutions (1:3 or 1:10) of 3 different fluids: saline (0.9% NaCl) solution, 6% HES 670/0.75, or 6% HES 130/0.4. Dilutions were calculated to simulate approximately a 10- or 30-mL/kg body weight IV bolus of each fluid. DVC was performed on each sample. Coagulation parameters compared between groups included clot rate (CR), platelet function (PF), and activated clotting time., Results: Dilution with saline solution did not significantly affect coagulation, while dilution with HES 670/0.75 and HES 130/0.4 caused a dose-dependent significant decrease in CR (1:3 HES 670/0.75, P = 0.007; 1:10 HES 670/0.75, P = 0.002; 1:3 HES130/0.4, P < 0.0001; and 1:10 HES 130/0.4, P = 0.0003) and PF (1:3 HES 670/0.75, P < 0.0001; 1:10 HES 670/0.75, P < 0.0001; 1:3 HES130/0.4, P < 0.0001; and 1:10 HES 130/0.4, P = 0.0015)., Clinical Relevance: Dilution of canine blood with HES 670/0.75 and HES 130/0.4, at clinically relevant doses (10 and 30 mL/kg), led to significant hypocoagulability beyond dilutional effect. This was, in part, due to impaired PF, which was significantly greater with HES 670/0.75. Further research using DVC to assess the effects of HES on coagulation in dogs, ideally with clinical conditions warranting HES administration, is needed.

Background: Both obesity and metabolic syndrome are associated with hypercoagulability in people, increasing the risk of cardiovascular disease and thromboembolic events. Whether hypercoagulability exists in obese, insulin-dysregulated horses is unknown., Hypothesis/objectives: To determine if coagulation profiles differ between healthy horses and those with obesity and insulin dysregulation., Animals: Fifteen healthy horses (CON) and 15 obese, insulin-dysregulated horses (OBID). Individuals were university or client owned., Methods: Case-control study. Obesity was defined as a body condition score (BCS) ≥7.5/9 (modified Henneke scale). Insulin dysregulation status was assessed by an oral sugar test (OST). Kaolin-thromboelastography and traditional coagulation variables were compared between groups. The direction and strength of the association between coagulation variables and BCS and OST results were determined using Spearman's correlation., Results: Thromboelastography variables MA (OBID: 69.5 ± 4.5 mm; CON: 64.8 ± 4.3 mm; P = .007) and G-value (OBID: 11749 ± 2536 dyn/m 2 ; CON: 9319 ± 1650 dyn/m 2 ; P = .004) were higher in OBID compared to CON. Positive correlations between MA and BCS (R = 0.45, P = .01) and serum insulin (T 0 : R = 0.45, P = .01; T 60 : R = 0.39, P = .03), and G-value and BCS (R = 0.46, P = .01), and serum insulin (T 0 : R = 0.48, P = .007; T 60 : R = 0.43, P = .02; T 90 : R = 0.38, P = .04) were present., Conclusions and Clinical Importance: Obese, insulin-dysregulated horses are hypercoagulable compared to healthy controls., (© 2022 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals LLC on behalf of American College of Veterinary Internal Medicine.)

Objective:  This study aimed to document rotational thromboelastometric (ROTEM) characteristics of traumatized cats and to investigate associations between clinicopathological parameters and acute traumatic coagulopathy (ATC). A secondary goal was to determine the relevance of autoheparinization in injured cats., Study Design:  Cats presenting with acute (<12 hours) trauma were eligible. Cats were allocated to the ATC group (≥2 hypocoagulable parameters) or non-ATC group (≤1 hypocoagulable parameter) based on ROTEM analysis. Clinicopathological parameters were compared between groups and regression was used to find variables associated with ATC. Heparinase-modified ROTEM (HepTEM) was used to assess for heparin effects in a subgroup., Results:  Fifty-three cats were included, and the incidence of ATC was 15%. Prolongation of both intrinsic and extrinsic clotting times (CT) was the most frequently altered ROTEM variable in the ATC group, but CT InTEM -prolongation also occurred in 47% of non-ATC cats. The incidence of autoheparinization, defined as concurrent CT InTEM prolongation and CT InTEM:HepTEM ratio >1.1, was 41% and was observed in both cats with and without ATC. None of the evaluated clinicopathological parameters were different between groups or associated with ATC., Conclusion:  Acute traumatic coagulopathy in cats is mainly characterized by prolonged CT. No relationship between clinicopathological variables and ATC was identified and prediction of ATC based on these variables was not possible. While autoheparinization is important in cats, it is not the sole cause for ATC., Competing Interests: None declared., (Thieme. All rights reserved.)

Thromboelastography (TEG) provides a global assessment of hemostasis and fibrinolysis and has broad applications to identify and monitor coagulation dysfunction in veterinary patients. Although alpacas are susceptible to a wide variety of coagulopathies, the assessment of TEG has not been reported in clinically healthy alpacas to date. The purpose of this study was to evaluate the analytical performance of recombinant human tissue factor (rhTF)- and kaolin-activated TEG and to establish reference intervals for TEG parameters (reaction [R] and clotting [K] times, angle [α], maximum amplitude [MA], and shear elastic modulus [G]) in healthy, adult alpacas. Kaolin and rhTF-activated TEG were performed using citrated whole blood samples from 20 clinically healthy, nonpregnant, adult Huacaya alpacas each after 30 min of sample storage at room temperature. Six individuals of a related species, dromedary camels, were also sampled for comparative purposes. All data were presented descriptively, assessed for normality, and compared using either independent-sample t tests or Mann-Whitney U tests, with P ≤ 0.05 considered significant. Reference intervals were calculated using a robust method and Box-Cox-transformed data. Mean TEG values (reference intervals) were determined for rhTF-activated TEG as follows: R 6.99 min (3.41-12.71), K 3.43 min (1.61-6.42), α 48.51° (27.21-67.38), MA 52.05 mm (21.53-65.92), and G 5.71 kdyn/cm 2 (1.87-9.60), while mean values (reference intervals) for kaolin-activated TEG included R 7.72 min (4.48-11.43), K 4.24 min (2.03-9.20), α 45.06° (23.66-64.20), MA 52.18 mm (33.49-66.63), and G 5.78 kdyn/cm 2 (NR-9.66). None of the measured TEG values differed significantly between activators, suggesting that activator choice may have a limited effect on TEG parameters in healthy alpacas. TEG results in alpacas were comparable to those of dromedary camels. These results will thus provide a useful starting point in the evaluation of hemostasis in adult camelids.

Background: Traditional viscoelastic clotting tests are significantly impacted by the operator and environmental variation. The VCMVet coagulation monitor could provide a more user-friendly alternative for veterinary practices., Objectives: We aimed to determine if environmental vibration commonly encountered in veterinary practice alters the results of a point-of-care viscoelastic device, the VCMVet., Methods: Nine fresh whole blood samples from healthy dogs were evaluated simultaneously using VCMVet instruments under four environmental conditions: (normal) alone and undisturbed on a raised tabletop, (centrifuge) on a countertop 6 inches from a centrifuge that operated at 12 000 rpm for 10 minutes every 20 minutes, (workspace) on a tabletop workspace in proximity to two heavy-use computers, and (gurney) on a rolling gurney at a walking pace for 10 minutes every 20 minutes. Results were compared between conditions using a Friedman test, and if this was significant (P-value < .05), it was followed by a Wilcoxon test for paired samples., Results: Analysis of samples on a rolling gurney created obvious movement artifacts, and this condition was excluded from statistical analysis. The centrifuge condition resulted in a significantly higher alpha angle (median 49 degrees, interquartile range 4) than the normal condition (median 46 degrees, interquartile range 5, P = .0078). Other viscoelastic parameters were not significantly different between the normal, centrifuge, and workspace conditions., Conclusions: The VCMVet is suitable for use in a busy veterinary environment but should be protected from vibration. The instrument does not produce reliable results when operated on a moving gurney, and it should be stationary during sample analysis., (© 2022 American Society for Veterinary Clinical Pathology.)

Viscoelastic testing methods such as thromboelastography (TEG) are becoming increasingly available to veterinarians in a clinical setting. TEG is useful in determining therapeutic transfusion needs and assessing global abnormalities of hemostasis of patients, given that it provides a more comprehensive assessment of coagulation than traditional tests. TEG is standardly performed at 37°C, which is considered a normal body temperature for human patients; however, 37°C is lower than normal body temperature for most canine patients. In an in vitro study, we investigated the potential effect that this difference in body temperature and test temperature might have on TEG results. Citrated blood samples were collected from clinically normal, as well as sick, dogs with various body temperatures. Samples were analyzed concurrently at the patient's body temperature and at 37°C. There was very high correlation between TEG performed at body temperature and at 37°C for R (min) and MA (mm), high correlation for K (min) and alpha angle (deg), and moderate correlation for LY30 (%) and LY60 (%). For canine patients with normal to mildly abnormal body temperatures, performance of TEG at the standard 37°C is acceptable.

Objective: To compare the effects of open-tube blood sampling with previously investigated blood sampling methods via evacuated tube on thromboelastography variables for blood samples from dogs., Animals: 10 healthy Beagles from the research colony owned by the Clinic of Small Animal Internal Medicine, University Veterinary of Medicine, Vienna, were used., Procedures: In this prospective study, blood was sampled from each dog serially into citrate solution-containing tubes via 20-gauge needle. One evacuated tube was filled from a jugular vein via the evacuated tube port, and the second tube was opened and filled by catching blood flowing through the needle from a lateral saphenous vein. Venipuncture quality was scored with a previously described method. Thromboelastography was performed for each sample., Results: Inferential statistics used with the Wilcoxon signed rank test showed significant differences in reaction time (R) of 3.43 ± 0.84 minutes versus 4.53 ± 0.62 minutes (mean ± SD) between evacuated tube assisted and open-tube sampling, respectively. No other significant differences were identified., Clinical Relevance: The sampling methods compared have a small but significant effect on R in thromboelastographic analysis for blood samples from healthy dogs. Shear stress by vacuum sampling seems to accelerate coagulation in jugular blood samples harvested by evacuated tube, resulting in a shortened R. Results suggested that the open-tube method avoids shear stress induced activation of coagulation and is an appropriate sampling method for thromboelastography when used within a standardized protocol.

Background: Critically ill horses, such as horses with gastrointestinal (GI) disease, often suffer from hemostatic aberrations. Global hemostatic tests examining the initiation of coagulation, clot strength and fibrinolysis, such as the Calibrated Automated Thrombogram (CAT) and plasma-thromboelastography (TEG) have not been evaluated in horses. This study aimed to evaluate CAT and apply plasma-TEG in horses. Test performance of CAT was evaluated on equine platelet poor plasma with intra- and inter-assay variability (CV) and a heparin dilution curve. To examine clinical performance of both tests, group comparisons were assessed comparing healthy horses, horses with mild and severe GI disease with both CAT and plasma-TEG., Results: For CAT, intra- and inter-assay CVs were established for lag-time (1.7, 4.7%), endogenous thrombin potential (1.6, 4.6%), peak (2.6, 3.9%) and time to peak (ttPeak) (1.9, 3.4%). Increasing heparin concentrations led to the expected decrease in thrombin generation. In the group comparison analysis, CAT showed significant higher peak (p = 0.04) and ttPeak (p = 0.008) in the severe GI disease group compared to horses with mild GI disease and healthy horses, respectively. Plasma-TEG showed an increased angle (p = 0.032), maximum amplitude (p = 0.017) and shear elastic force (G) (p = 0.017) in the severe GI disease group compared to healthy horses., Conclusions: CAT performed well in horses. Both CAT and plasma-TEG identified hemostatic aberrations in horses with severe GI disease compared to healthy horses. Further studies including more horses, are needed to fully appreciate the use of CAT and plasma-TEG in this species., (© 2021. The Author(s).)

Objective: To compare the impact of an IV bolus of hydroxyethyl starch 130/0.4 (HES) or hypertonic saline 7.5% (HS) on hemostasis in dogs resuscitated for gastric-dilation-volvulus (GDV)., Design: Open-label, parallel-group randomized clinical trial., Animals: Twenty-three client-owned dogs., Interventions: Dogs affected by GDV and shock were randomly assigned to receive HES at 10 mL/kg or HS at 4 mL/kg every 15 minutes. Blood samples were collected for blood gas analysis, PCV, total plasma protein, albumin, standard coagulation profile, and thromboelastometry (ROTEM) at baseline (T0) and at the end of bolus (T1). To assess the differences between the 2 groups at T1, Student's t-test or Wilcoxon rank-sum test was used. To evaluate the differences between T0 and T1, ANOVA for paired data or Wilcoxon matched-pairs signed-ranks test was used. P < 0.05 was considered significant., Measurement and Main Results: Hemostasis was evaluated by means of prothrombin time, activated partial thromboplastin time, fibrinogen, and ROTEM. The study included 13 dogs in the HES group and 10 dogs in the HS group. Differences were found between groups at T1: increase in clotting time (P = 0.018) and decrease in fibrinogen level (P = 0.021) in the HS-treated group. Between T0 and T1, there were differences for the HES group: increase in clot formation time (P = 0.046), decrease in maximum clot firmness (P = 0.002) in ex-TEM profile, and decrease in maximum clot firmness (P = 0.0117) in fib-TEM profile. Between T0 and T1, the following differences were noted for the HS group: increase in clotting time (P = 0.048) and clot formation time (P = 0.0019), decrease in maximum clot firmness (P = 0.031) and α angle (P = 0.036) in ex-TEM profile, decrease in α angle (P = 0.036) in in-TEM profile, and decrease in maximum clot firmness (P = 0.017) in fib-TEM profile., Conclusion: In dogs affected by GDV, HES or HS infusion caused a similar tendency toward hypocoagulability, with few differences between the 2 groups., (© Veterinary Emergency and Critical Care Society 2021.)

Protein-losing enteropathy (PLE) is known to induce hypercoagulability and resultant thromboembolism in dogs. We hypothesized that hypercoagulability would improve if remission was obtained in dogs with PLE after treatment. This study aimed to evaluate the changes in the coagulation parameters after treatment in dogs diagnosed with PLE. As coagulation parameters, prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen, thrombin-antithrombin complex (TAT), D-dimer, and antithrombin (AT) were measured. In addition to these parameters, rotational thromboelastometry (ROTEM), which evaluates the comprehensive coagulation and fibrinolysis reactions of whole blood, was conducted and the data of clotting time (CT), clot formation time (CFT), α angle (α), maximum clot firmness (MCF) and lysis index at 60 min (LI60) were obtained. Eleven of the 14 dogs diagnosed with PLE were classified as responders to the treatment based on the changes in their plasma albumin (ALB) concentration after treatment. Significant increase in CFT and decrease of α and MCF indicating the resolution of hypercoagulability were found after treatment in responder dogs; however, there was no significant change in the coagulation and fibrinolysis parameters other than those measured by ROTEM. This study demonstrated that the hypercoagulability detected by ROTEM was significantly improved after treatment in dogs with PLE.

Background: Gallbladder mucocele (GBM) is a common biliary disorder in dogs. Limited information is available on the coagulation status of dogs with GBM., Hypothesis/objectives: To determine patterns of coagulation alterations in dogs with GBM and correlate them with clinicopathologic abnormalities and ultrasonographic findings of disease severity., Animals: Twenty-three dogs with GBM identified on ultrasound examination were prospectively enrolled., Methods: At the time of GBM identification, blood and urine were collected for CBC, serum biochemical panel, urinalysis, prothrombin time, activated partial thromboplastin time (aPTT), factor VIII, protein C (PC), von Willebrand's factor (vWF), antithrombin activity, fibrinogen, D-dimers, and thromboelastrography (TEG). Gallbladder mucoceles were classified into ultrasound types 1 to 5. Medical records were reviewed for clinical presentation, underlying conditions and to determine if systemic inflammatory response syndrome (SIRS) was present., Results: Based on TEG parameters, maximal amplitude, and G, 19/23 (83%) of dogs with GBM had evaluations consistent with hypercoagulability. On plasma-based coagulation testing, dogs with GBM had increased total PC activity (20/23, 87%), fibrinogen (9/23, 39%), platelet count (9/23, 39%), and D-dimers (6/15, 40%) as well as prolongations in aPTT (9/22, 41%) and low vWF activity (5/21, 24%). No correlation was found between TEG G value and any coagulation or clinical pathology variables, ultrasound stage of GBM or disease severity as assessed by the presence of SIRS., Conclusions and Clinical Importance: Dogs with ultrasonographically identified GBM have changes in whole blood kaolin-activated TEG supporting a hypercoagulable state although traditional plasma-based coagulation testing suggests that a complex state of hemostasis exists., (© 2021 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals LLC on behalf of American College of Veterinary Internal Medicine.)

Objectives: The aims of this study were to determine if there is increased risk of intraoperative bleeding in pregnant cats undergoing elective ovariohysterectomy (OHE), and to compare coagulation in queens in various stages of estrus and pregnancy subjected to elective OHE using a whole-blood viscoelastic assay., Methods: Intraoperative blood loss was compared between non-pregnant and pregnant cats undergoing elective OHE. Viscoelastic evaluations of whole blood drawn pre- and postoperatively were performed using a point-of-care device measuring clot time (CT), clot formation time (CFT), alpha angle, maximum clot formation (MCF), amplitude at 10 and 20 mins (A10 and A20, respectively), and lysis index at 30 and 45 mins after MCF (LI30 and LI45, respectively)., Results: One hundred and ninety-three cats underwent OHE by a ventral midline approach. Median blood loss was greater for pregnant cats (2.0 ml, range <0.5-13 ml) than non-pregnant cats (<0.5 ml, range <0.5-15 ml; P <0.0001). Preoperatively, pregnant cats had a shorter median CFT (165 s vs 190.5 s), increased median A10 (31 from 25.5 VCM units) and A20 (38 from 35 VCM units), and a lower median LI45 (99% from 100%) than non-pregnant cats. Postoperatively, A10 and A20 increased, and LI30 and LI45 decreased in both non-pregnant and pregnant queens. In pregnant queens, mean CT also increased postoperatively., Conclusions and Relevance: Pregnant cats were relatively hypercoagulable and had an increased rate of clot lysis than non-pregnant cats. Intraoperative blood loss was increased in pregnant vs non-pregnant cats, but no clinically relevant bleeding conditions occurred.

Background: Coagulation abnormalities, including hyperfibrinolysis, have been documented in sick veterinary patients. Viscoelastic tests, including the Sonoclot Coagulation and Platelet Function Analyzer, are useful in detecting hyperfibrinolysis. Tissue plasminogen activator (tPA) assays have been used to quantify fibrinolysis using thromboelastography., Objectives: We aimed to document and evaluate changes in the whole blood of healthy dogs exposed to in vitro tPA at varying concentrations using the Sonoclot analyzer., Methods: Ten milliliters of blood was collected from healthy adult dogs. Sonoclot tests were run in duplicate and included a control sample and five tPA concentrations: 50, 75, 100, 150, and 200 IU/mL of blood., Results: Eleven dogs were enrolled in the study. Based on standard Sonoclot Signature changes, a numeric value fibrinolysis time (FTi) was derived to aid in the quantification of hyperfibrinolysis. Activated clotting time and clot rate Sonoclot values were not significantly affected by any tPA concentration. There was a significant decrease in platelet function (PF) at tPA concentrations equal to and above 75 IU/mL on channel 1 and tPA concentrations of 150 IU/mL and higher on channel 2. There was a progressive decrease in FTi at increasing tPA concentrations., Conclusions: The Sonoclot analyzer can be used to evaluate hyperfibrinolysis. Predictable changes were seen in the Sonoclot Signature and a decrease in PF and FTi was found with increasing tPA concentrations. The Sonoclot assay with a tPA concentration of 100 IU/mL is suggested a baseline measure of hyperfibrinolysis and has a resultant median FTi of 42 minutes, which is a practical time for clinical applications., (© 2021 American Society for Veterinary Clinical Pathology.)

Primary hyperfibrinolysis is not well characterised in canine cancer. This prospective case-control pilot study aimed to evaluate tissue plasminogen activator-modified thromboelastography (tPA-TEG) for diagnosis of primary hyperfibrinolysis in dogs with cancer and establish the in vitro therapeutic concentration of tranexamic acid (TXA). Nine dogs with sarcomas and normocoagulable thromboelastograms and 11 healthy dogs were included. For each a whole blood tPA-TEG, and four tPA-TEGs with added TXA in different concentrations were analysed. Lysis percentage at 30/60 min following maximal amplitude (LY30/60), clot lysis index (CL30/60), maximum rate of lysis (MRL), and total lysis (L) were investigated as diagnostic parameters of primary hyperfibrinolysis. In vitro TXA concentrations needed to inhibit 50% (IC50) and 90% (IC90) of the fibrinolytic potential were compared between groups. Significant primary hyperfibrinolysis (LY30 (P = 0.0001), LY60 (P = 0.003), CL30 (P = 0.01), and L (P = 0.02)) was observed in dogs with sarcomas. IC50 and IC90 of in vitro TXA for normalizing LY30 were 13.34 (SE 1.52) and 31.10 (SE 3.01) mg/L for dogs with sarcomas and 4.41 (SE 5.84) and 20.00 (SE 6.18) mg/L for healthy dogs. IC50 and IC90 for normalizing LY60 were 22.18 (SE 1.27) and 58.94 (SE 5.47) mg/L for dogs with sarcomas and 11.25 (SE 2.82) and 56.20 (SE 11.61) mg/L for healthy dogs. The IC50 for LY60 was significantly increased for dogs with sarcomas (P = 0.0003). Primary hyperfibrinolysis was documented by tPA-TEG in dogs with sarcomas. In vitro IC50 and IC90 for TXA were established. Clinical studies are required to establish therapeutic dosages in vivo., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Objective:  The aim of this study was to describe the coagulation status of traumatized dogs over the first 24 hours after admission., Study Design:  In 33 dogs presenting within 6 hours after trauma blood was sampled for rotational thromboelastometry (ROTEM), thrombocyte number and venous blood gas analysis at presentation and 6 and 24 hours thereafter. At each time point, dogs were defined as hypo-, normo- or hypercoagulable based on extrinsic, intrinsic and fibrinogen ROTEM profiles., Results:  Significantly more dogs (11/33) presented hypocoagulable compared with 6 hours ( p  = 0.046) and 24 hours ( p  = 0.008) thereafter and none presented hypercoagulable. Significantly more dogs were hypercoagulable (6/23, p  = 0.014) and no dog was hypocoagulable at 24 hours compared with presentation. All evaluated ROTEM parameters except maximum lysis were significantly more hypocoagulable at presentation compared with 24 hours thereafter., Conclusion:  Hypocoagulability is more common in acutely traumatized dogs than previously described. Dogs were hypo- or normocoagulable at presentation and the coagulation status changed to normo- or hypercoagulability over the first 24 hours. Clotting times, clot formation and clot firmness but not clot lysis were significantly altered at presentation compared with 24 hours and fibrinogen concentration or function may play an important role in the dynamic change of coagulation state over time., Competing Interests: None declared., (Thieme. All rights reserved.)

Objective:  The aim of this study was to determine the prevalence of acute traumatic coagulopathy (ATC) and identify associated clinical and laboratory parameters including rotational thromboelastometry., Study Design:  Dogs presenting within 6 hours after trauma were allocated to the ATC or non-ATC group based on thromboelastometry analysis (ex-tem S, in-tem S, fib-tem S). ATC was defined as ≥2 hypocoagulable parameters in 1 profile and ≥ 1 hypocoagulable parameter in an additional profile. Parameters used were ex-tem and in-tem clotting time (CT), clot formation time (CFT), maximum clot firmness (MCF), maximum lysis and fib-tem MCF. Clinical and laboratory parameters at presentation, animal trauma triage (ATT) score, transfusion requirement and outcome were compared. Logistic regression was used to identify independent factors associated with ATC., Results:  Eleven of 33 dogs presented with ATC and showed ex-tem CT and CFT prolongation and reduced MCF amplitude in all profiles (all p <  0.001). pH ( p =  0.043) and potassium concentration ( p =  0.022) were significantly lower and bleeding ( p =  0.027) and plasma transfusions (p =  0.001 ) more common in dogs with ATC. Time after trauma ( p =  0.040) and Animal Trauma Triage score ( p =  0.038, including haematocrit as confounding factor) were associated with the presence of ATC., Conclusion:  Acute traumatic coagulopathy is more common in traumatized dogs than previously reported. Acute traumatic coagulopathy was associated with acidosis, Animal trauma triage score, time after trauma and higher transfusion needs. Coagulation abnormalities include ex-tem CT and CFT prolongations and decreased clot strength., Competing Interests: None declared., (Thieme. All rights reserved.)

Background: Dogs with protein-losing enteropathy (PLE) are at risk of developing a hypercoagulable state, but the prevalence of hypercoagulability in dogs with chronic enteropathies (CE) and normal serum albumin concentration is unknown., Hypothesis: Dogs with CE are predisposed to a hypercoagulable state as assessed by thromboelastography (TEG) independent of serum albumin concentration., Methods: Dogs with chronic gastrointestinal signs from suspected inflammatory CE between 2017 and 2019 were included. Thirty-eight were evaluated; every dog had a CBC, serum biochemistry panel, and abdominal imaging performed. The Canine Inflammatory Bowel Disease Activity Index (CIBDAI) was calculated. Thromboelastography was performed at presentation, and reaction time (R), kinetic time (K), α-angle, maximal amplitude (MA), and global clot strength (G) were recorded. Dogs were considered hypercoagulable if the G value was ≥25% above the reference interval., Results: Seventeen of 38 (44.7%; 95% confidence interval [CI], 28.6-61.7%) dogs with CE were hypercoagulable. The G value did not differ between the 19 dogs with normal (≥28 g/L) serum albumin concentrations (9.05 kdyn/cm 2 ; 95% CI, 7.26-10.84; SD 3.71) and 19 dogs with hypoalbuminemia (11.3 kdyn/cm 2 ; 95% CI, 9.04-13.6, SD; 4.7; P = .11). The G value was negatively correlated with hematocrit, serum albumin concentration, and duration of signs and positively correlated with age., Conclusions and Clinical Importance: Dogs with CE and normal serum albumin concentration can be hypercoagulable as measured by TEG., (© 2021 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals LLC. on behalf of the American College of Veterinary Internal Medicine.)