Bleeding In Dogs Research Articles

The use of a kaolin-based hemostatic dressing to attenuate bleeding in dogs: A series of 4 cases.

To describe the use of a synthetic hemostatic dressing, QuikClot Combat Gauze (QCG), in dogs with bleeding wounds. Two dogs presented with bleeding traumatic wounds, and QCG was used to achieve hemostasis during stabilization of these dogs. In the other 2 dogs, QCG was used to help attenuate bleeding associated with a surgical procedure. While hemostatic dressings have been widely studied and used in human medicine, there is minimal information on the use and efficacy of these hemostatic dressings in veterinary medicine. This case series describes the use of QCG in dogs with hemorrhaging wounds. QCG could be a valuable resource in veterinary emergency and critical care settings.

Estimativa de perda sanguínea transoperatória em cães submetidos a hemilaminectomia e fenestração do disco intervertebral

ABSTRACT: There are no reported estimates of normal or abnormal bleeding in dogs during the hemilaminectomy and intervertebral disc fenestration procedures (HF), and that makes it difficult to study intraoperative complications, hemostasis methods, and the impact of bleeding on surgical performance. This prospective study estimated blood loss during HF procedures in dogs with intervertebral disc extrusion (IVDE). Blood loss was quantified by weighing gauzes during the surgical procedure, in addition to measuring the aspirated blood. Total blood volume was estimated according to body weight, and blood loss as a percentage of the total blood volume. The surgeon also subjectively classified the procedures, dividing them into intraoperative difficulty due to bleeding (G1) and absence of intraoperative difficulty (G2). Thirty-two dogs that underwent HF due to IVDE were included. The median blood loss (%) of dogs submitted to HF was 3.9 ± 9.67 of the total blood volume. There was a weak correlation between blood loss and weight, age, incision size, and procedure time.

Plasma urea:creatinine ratio as a biomarker of gastrointestinal bleeding in dogs with anaemia.

Gastrointestinal bleeding is a cause of anaemia in dogs. A reliable, non-invasive biomarker to differentiate gastrointestinal bleeding from other causes of anaemia would be advantageous to direct clinical decisions in anaemic patients. Plasma urea:creatinine ratio is an accepted biomarker of upper gastrointestinal bleeding in human medicine. The objective of this study was to evaluate plasma urea:creatinine ratio as a biomarker of gastrointestinal bleeding in a population of dogs with anaemia. This was a prospective cross-sectional study of dogs with anaemia presenting to referral centres for the investigation of anaemia. Cases were categorised as having overt gastrointestinal bleeding (melena on presentation), occult gastrointestinal bleeding (historical and diagnostic findings consistent with gastrointestinal bleeding without melena at presentation) or anaemia of other cause (confident diagnosis other than gastrointestinal bleeding reached, normal diagnostic imaging of gastrointestinal tract). Urea:creatinine ratio at presentation was calculated by dividing urea (mg/dL) by creatinine (mg/dL). Ninety-five dogs were included. Plasma urea:creatinine ratio was not significantly different between dogs with overt or occult gastrointestinal bleeding or those with anaemia of other cause (median urea:creatinine ratio 25.8, 20.7 and 22.5, respectively). No significant difference in urea:creatinine ratio was found between dogs with upper and lower gastrointestinal bleeding (median urea:creatinine ratio 19.4 and 24.6, respectively). Plasma urea:creatinine ratio was not helpful in differentiating between dogs with anaemia resulting from gastrointestinal bleeding (overt or occult) and those with other causes of anaemia.

Tranexamic Acid in Reducing Intraoperative Bleeding in Dogs Undergoing Thoracolumbar and Lumbar Hemilaminectomy and Intervertebral Disc Fenestration

Hemilaminectomy associated with intervertebral disc fenestration (HF) is the most used spinal decompression surgical technique for the treatment of intervertebral disc extrusion (IVDE). The surgical procedure can be hampered by excessive bleeding from the venous sinuses; however, tranexamic acid intravenously (IV) is a possible adjunct to hemostasis in these patients. This study aimed to verify the effectiveness of tranexamic acid in reducing intraoperative bleeding in dogs with thoracolumbar and lumbar IVDE submitted to HF. Sixteen dogs with IVDE undergoing HF were included. These were distributed into a TXA group (tranexamic acid 20 mg/kg IV bolus, followed by 2 mg/kg/h IV continuous infusion) (n = 8) and a control group, with saline solution (n = 8). Blood loss was measured using the gravimetric method. The difficulty of operative visualization due to bleeding was classified by the surgeon. Median blood loss (%) in patients in the TXA group was lower than those in the control group (2.75 ± 1.23 and 4.99 ± 4.44, respectively) (P = .028). Intraoperative visualization difficulty due to bleeding occurred in 10 patients in the control group, and in no patients in the TXA group. A severe arterial thromboembolic complication was recorded, potentially due to tranexamic acid. The use of intraoperative tranexamic acid was effective in reducing bleeding and facilitating operative visualization in dogs with IVDE undergoing hemilaminectomy and intervertebral disc fenestration.

Retrospective evaluation of the incidence of gastrointestinal bleeding in dogs receiving ophthalmic nonsteroidal anti-inflammatory drugs.

To report the incidence of gastrointestinal (GI) bleeding and associated risk factors in a population of dogs receiving ophthalmic nonsteroidal anti-inflammatory drugs (NSAIDs). Medical records of dogs prescribed ophthalmic NSAIDs (cases), dogs receiving systemic NSAIDs alone and dogs receiving systemic prednisone alone (controls). Data were collected retrospectively from the medical records of 204 dogs prescribed ophthalmic NSAIDs (diclofenac, ketorolac, or flurbiprofen), which were subdivided based on if they received any concurrent systemic NSAIDs or glucocorticoids, 136 dogs receiving a systemic NSAID (carprofen or meloxicam) alone, and 151 dogs receiving a systemic glucocorticoid (prednisone) alone at a referral hospital from 2015 to 2019. Gastrointestinal bleeds developed in 8/79 (10.1%) of topical NSAID-only cases, 10/136 (7.4%) of systemic NSAID controls, and 14/151 (9.3%) of systemic glucocorticoid controls, with no significant difference between the three groups (p = .6103). There were no significant differences in GI bleed rates between cases treated with ketorolac, diclofenac, or flurbiprofen (p = .160), although severe GI bleeding was only seen in ketorolac-treated dogs. Presence of a known concurrent risk factor for GI bleeding was significantly associated with the development of GI bleed in dogs on ophthalmic NSAIDs (p = .032). Dogs treated with ophthalmic NSAIDs developed GI bleeding at a frequency comparable to dogs receiving systemic NSAIDs or systemic glucocorticoids alone, suggesting that dogs receiving ophthalmic NSAIDs may be at increased risk of GI bleeding.

Clinicopathologic and gastrointestinal effects of administration of prednisone, prednisone with omeprazole, or prednisone with probiotics to dogs: A double-blind randomized trial.

The efffect of administering of probiotics or twice-daily omeprazole on glucocorticoid-induced gastric bleeding in dogs is unknown. Compare gastrointestinal bleeding among dogs administered placebo, prednisone (2mg/kg q24h), prednisone with omeprazole (1mg/kg q12h), or prednisone with probiotics (Visbiome, 11.2-22.5 billion CFU/kg q24h) for 28 days. Twenty-four healthy research dogs. Double-blinded, placebo-controlled randomized trial. Clinical signs and endoscopic gastrointestinal mucosal lesion scores at baseline (t1 ), day 14 (t2 ), and day 28 (t3 ) were compared using split-plot repeated-measures mixed-model ANOVAs. Fecal score differed by treatment-by-time (F[6,40] = 2.65, P < .03), with higher scores in groups receiving prednisone at t3 than t1 . Nineteen of thirty-three episodes of diarrhea occurred in the prednisone with omeprazole group. Gastric mucosal lesion scores differed by treatment-by-time (F[6,60] = 2.86, P=.05), among treatment groups (F[3,60] = 4.9, P=.004), and over time (F[2,60] = 16.5, P < .001). Post hoc analysis revealed lesion scores increased over time for all groups receiving prednisone. At t3 , scores for the prednisone (8.7 ± 4.9) and prednisone with probiotics (8.7 ± 4.9) groups differed significantly from placebo (1.8 ± 1.8; P ≤ .04), whereas scores for the prednisone with omeprazole (6.5 ± 5.5) group did not differ from placebo (P=.7). Ulcers occurred only in dogs receiving prednisone. Prednisone-induced gastric bleeding. Co-administration of omeprazole partially mitigated bleeding, but a similar protective benefit was not demonstrated by co-administration of the evaluated probiotic.

Effect of early administration of tranexamic acid on ongoing haemorrhage in dogs with non-surgically treated haemoabdomen.

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.

Resuscitation Patterns and Massive Transfusion for the Critical Bleeding Dog-A Multicentric Retrospective Study of 69 Cases (2007-2013).

Objective: To describe resuscitation patterns of critically bleeding dogs, including those receiving massive transfusion (MT).Design: Retrospective study from three universities (2007–2013).Animals: Critically bleeding dogs, defined as dogs who received ≥ 25 ml/kg of blood products for treatment of hemorrhagic shock caused by blood loss.Measurements and Main Results: Sixty-nine dogs were included. Sources of critical bleeding were trauma (26.1%), intra/perioperative surgical period (26.1%), miscellaneous (24.6%), and spontaneous hemoabdomen (23.1%). Median (range) age was 7 years (0.5–18). Median body weight was 20 kg (2.6–57). Median pre-transfusion hematocrit, total protein, systolic blood pressure, and lactate were 25% (10–63), 4.1 g/dl (2–7.1), 80 mm Hg (20–181), and 6.4 mmol/L (1.1–18.2), respectively. Median blood product volume administered was 44 ml/kg (25–137.4). Median plasma to red blood cell ratio was 0.8 (0–4), and median non-blood product resuscitation fluid to blood product ratio was 0.5 (0–3.6). MT was given to 47.8% of dogs. Survival rate was 40.6%. The estimated odds of survival were higher by a factor of 1.8 (95% CI: 1.174, 3.094) for a dog with 1 g/dl higher total protein above reference interval and were lower by a factor of 0.6 (95% CI: 0.340, 0.915) per 100% prolongation of partial thromboplastin time above the reference interval. No predictors of MT were identified.Conclusions: Critical bleeding in dogs was associated with a wide range of resuscitation patterns and carries a guarded to poor prognosis.

The Angiostrongylus vasorum Excretory/Secretory and Surface Proteome Contains Putative Modulators of the Host Coagulation.

Angiostrongylus vasorum is a cardiopulmonary nematode of canids and is, among others, associated with bleeding disorders in dogs. The pathogenesis of such coagulopathies remains unclear. A deep proteomic characterization of sex specific A. vasorum excretory/secretory proteins (ESP) and of cuticular surface proteins was performed, and the effect of ESP on host coagulation and fibrinolysis was evaluated in vitro. Proteins were quantified by liquid chromatography coupled to mass spectrometry and functionally characterized through gene ontology and pathway enrichment analysis. In total, 1069 ESP (944 from female and 959 from male specimens) and 1195 surface proteins (705 and 1135, respectively) were identified. Among these were putative modulators of host coagulation, e.g., von Willebrand factor type D domain protein orthologues as well as several proteases, including serine type proteases, protease inhibitors and proteasome subunits. The effect of ESP on dog coagulation and fibrinolysis was evaluated on canine endothelial cells and by rotational thromboelastometry (ROTEM). After stimulation with ESP, tissue factor and serpin E1 transcript expression increased. ROTEM revealed minimal interaction of ESP with dog blood and ESP did not influence the onset of fibrinolysis, leading to the conclusion that Angiostrongylus vasorum ESP and surface proteins are not solely responsible for bleeding in dogs and that the interaction with the host’s vascular hemostasis is limited. It is likely that coagulopathies in A. vasorum infected dogs are the result of a multifactorial response of the host to this parasitic infection.

Correlation of plasma coagulation tests and fibrinogenClauss with rotational thromboelastometry parameters and prediction of bleeding in dogs.

BackgroundCorrelation of plasma fibrinogen concentration (fibrinogenClauss) with rotational thromboelastometry (ROTEM) parameters has not been investigated in dogs.ObjectivesTo determine the correlation between plasma coagulation tests and fibrinogenClauss with ROTEM parameters and to evaluate their ability to predict bleeding in dogs.AnimalsNinety‐seven dogs with concurrent determination of fibrinogenClauss and fibrin polymerization test (FIBTEM) analysis.MethodsSignalment, pretreatment, clinical signs of bleeding, fibrinogenClauss, plasma coagulation test results, hematocrit, platelet count, FIBTEM, extrinsic (EXTEM) and intrinsic (INTEM) activated ROTEM assays were retrieved retrospectively. Correlations between fibrinogenClauss and FIBTEM maximum clot firmness (MCFFIBTEM) and between prothrombin time (PT) or activated partial thromboplastin time (aPTT) and ROTEM parameters were determined. Dogs were further assigned to groups with or without clinical signs of bleeding. The prognostic significance of significantly different parameters to predict bleeding was evaluated.ResultsFibrinogenClauss showed strong correlation with MCFFIBTEM (r = 0.860, n = 97, P < .001). PT showed strong correlation with EXTEM clotting time (CTEXTEM) (r = 0.839, n = 53, P < .001), and aPTT was strongly correlated with INTEM CT (CTINTEM) (r = 0.664, n = 31, P < .001). Platelet count, PT/aPTT, EXTEM clot formation time (CFTEXTEM), MCFEXTEM, EXTEM maximum clot elasticity (MCEEXTEM), and CTINTEM were significantly different between groups. A CTINTEM >149 seconds was 100% sensitive to detect bleeding.Conclusions and Clinical ImportanceThe MCFFIBTEM can be used to evaluate the effect of fibrinogen on hemostasis as an alternative to determination of fibrinogenClauss. In addition, CTEXTEM and CTINTEM are strongly correlated with PT and aPTT, respectively.

Development and implementation of a novel immune thrombocytopenia bleeding score for dogs.

BackgroundA method of quantifying clinical bleeding in dogs with immune thrombocytopenia (ITP) is needed because ITP patients have variable bleeding tendencies that inconsistently correlate with platelet count. A scoring system will facilitate patient comparisons and allow stratification based on bleeding severity in clinical trials.Hypothesis/ObjectivesTo develop and evaluate a bleeding assessment tool for dogs, and a training course for improving its consistent implementation.AnimalsClient‐owned dogs (n = 61) with platelet counts <50,000/μL; 34 classified as primary ITP, 17 as secondary ITP, and 10 as non‐ITP.MethodsA novel bleeding assessment tool, DOGiBAT, comprising bleeding grades from 0 (none) to 2 (severe) at 9 anatomic sites, was developed. Clinicians and technicians completed a training course and quiz before scoring thrombocytopenic patients. The training course was assessed by randomizing student volunteers to take the quiz with or without prior training. A logistic regression model assessed the association between training and quiz performance. The correlation of DOGiBAT score with platelet count and outcome measures was assessed in the thrombocytopenic dogs.ResultsClinicians and technicians consistently applied the DOGiBAT, correctly scoring all quiz cases. The odds of trained students answering correctly were higher than those of untrained students (P < .0001). In clinical cases, DOGiBAT score and platelet count were inversely correlated (r s = −0.527, P < .0001), and DOGiBAT directly correlated with transfusion requirements (r s = 0.512, P < .0001) and hospitalization duration (r s = 0.35, P = .006).Conclusions and Clinical ImportanceThe DOGiBAT and assessment quiz are simple tools to standardize evaluation of bleeding severity. With further validation, the DOGiBAT may provide a clinically relevant metric to characterize ITP severity and monitor response in treatment trials.

Hyperfibrinolysis and Hypofibrinogenemia Diagnosed With Rotational Thromboelastometry in Dogs Naturally Infected With Angiostrongylus vasorum.

BackgroundThe pathomechanism of Angiostrongylus vasorum infection‐associated bleeding diathesis in dogs is not fully understood.ObjectiveTo describe rotational thromboelastometry (ROTEM) parameters in dogs naturally infected with A. vasorum and to compare ROTEM parameters between infected dogs with and without clinical signs of bleeding.AnimalsA total of 21 dogs presented between 2013 and 2016.MethodsDogs with A. vasorum infection and ROTEM evaluation were retrospectively identified. Thrombocyte counts, ROTEM parameters, clinical signs of bleeding, therapy, and survival to discharge were retrospectively retrieved from patient records and compared between dogs with and without clinical signs of bleeding.ResultsEvaluation by ROTEM showed hyperfibrinolysis in 8 of 12 (67%; 95% CI, 40–86%) dogs with and 1 of 9 (11%; 95% CI, 2–44%) dogs without clinical signs of bleeding (P = .016). Hyperfibrinolysis was associated with severe hypofibrinogenemia in 6 of 10 (60%; 95% CI, 31–83%) of the cases. Hyperfibrinolysis decreased or resolved after treatment with 10–80 mg/kg tranexamic acid. Fresh frozen plasma (range, 14–60 mL/kg) normalized follow‐up fibrinogen function ROTEM (FIBTEM) maximal clot firmness in 6 of 8 dogs (75%; 95% CI, 41–93%). Survival to discharge was 67% (14/21 dogs; 95% CI, 46–83%) and was not different between dogs with and without clinical signs of bleeding (P = .379).Conclusion and Clinical ImportanceHyperfibrinolysis and hypofibrinogenemia were identified as an important pathomechanism in angiostrongylosis‐associated bleeding in dogs. Hyperfibrinolysis and hypofibrinogenemia were normalized by treatment with tranexamic acid and plasma transfusions, respectively.

EVALUATION OF THE COMPUTED TOMOGRAPHIC "SENTINEL CLOT SIGN" TO IDENTIFY BLEEDING ABDOMINAL ORGANS IN DOGS WITH HEMOABDOMEN.

The CT "sentinel clot sign" has been defined as the highest attenuation hematoma adjacent to a bleeding organ in humans with hemoabdomen. The aims of this retrospective descriptive multicenter study were to describe CT findings in a sample of dogs with surgically or necropsy confirmed intra-abdominal bleeding and determine prevalence of the "sentinel clot sign" adjacent to the location of bleeding. Medical records between 2012 and 2014 were searched for dogs with hemoabdomen and in which the origin of the bleeding was confirmed either with surgery or necropsy. Retrieved CT images were reviewed for the presence and localization of the "sentinel clot sign," HU measurements of the "sentinel clot sign" and hemoabdomen, and presence of extravasation of contrast media within the abdominal cavity. Nineteen dogs were included. Three dogs were excluded due to the low amount of blood that did not allow the identification of a "sentinel clot sign." A "sentinel clot sign" was detected in the proximity of the confirmed bleeding organ in 14/16 (88%) of the patients. The mean HU of the "sentinel clot sign" was 56 (range: 43-70) while that of the hemoabdomen was 34 (range: 20-45). Active hemorrhage was identified as extravasation of contrast medium within the peritoneal cavity from the bleeding organ in three dogs. In conclusion, the CT "sentinel clot sign" may be helpful for identifying the source of bleeding in dogs with hemoabdomen.

Effects of dipyrone, meloxicam, or the combination on hemostasis in conscious dogs.

To compare the effects of dipyrone, meloxicam, and of the combination of these drugs on hemostasis in dogs. Prospective, blinded, randomized crossover study. Research laboratory at a veterinary teaching hospital. Six adult dogs. Animals received 4 intravenous treatments with 15-day washout intervals: control (physiological saline, 0.1 mL/kg), meloxicam (0.2 mg/kg), dipyrone (25 mg/kg), and dipyrone-meloxicam (25 and 0.2 mg/kg, respectively). A jugular catheter was placed for drug injection and for collecting samples for whole blood platelet aggregation (WBPA) and thromboelastometry assays at baseline, 1, 2, 3, 5, and 8 hours after treatment administration. The percent change from baseline of lag time and of the area under the curve (AUC) of impedance changes in response to collagen-induced platelet activation were recorded during WBPA. Thromboelastometry-derived parameters included clotting time, clot formation time, alpha-angle, and maximum clot firmness. The buccal mucosal bleeding time was evaluated by a blinded observer at baseline, 1, 3, and 5 hours after treatment injection. No significant changes in WBPA and thromboelastometry were recorded in the control treatment. Dipyrone significantly (P < 0.05) increased the lag time for 2 hours and decreased the AUC for 3 hours after injection. Meloxicam did not alter WBPA. Dipyrone-meloxicam significantly increased lag time for 2 hours and decreased the AUC for 5 hours after treatment injection. Experimental treatments did not differ from the control treatment for thromboelastometry and buccal mucosal bleeding time. While meloxicam does not alter hemostasis by the methods evaluated, dipyrone inhibits platelet aggregation for up to 3 hours. Meloxicam-dipyrone combination causes more prolonged inhibition of platelet function than dipyrone alone. Decreased platelet aggregation induced by dipyrone and dipyrone-meloxicam does not appear to impact the viscoelastic properties of the blood clot nor increase the risk of bleeding in dogs without preexisting hemostatic disorders.

Intraoperative bleeding in dogs from Grenada seroreactive to Anaplasma platys and Ehrlichia canis.

BackgroundFrequent exposure of Grenadian dogs to Rhipicephalus sanguineus results in Anaplasma platys, and Ehrlichia canis seroreactivity. During elective surgeries, substantial intraoperative hemorrhage occurs in some seroreactive dogs.ObjectivesTo assess hemostatic parameters and bleeding tendencies as well as prevalence of PCR positivity in apparently healthy A. platys and E. canis seroreactive and seronegative free‐roaming dogs from Grenada.AnimalsForty‐seven elective surgery dogs allocated to 4 groups: Seronegative control (n = 12), A. platys (n = 10), E. canis (n = 14) and A. platys, and E. canis (n = 11) seroreactive.MethodsPreoperatively, hemostasis was assessed by platelet count, prothrombin time, activated partial thromboplastin time, and buccal mucosal bleeding time. Intra‐ and postoperative bleeding scores were subjectively assigned. Blood, spleen, bone marrow, and lymph node aspirates were tested by PCR.ResultsBleeding scores in dogs coseroreactive for A. platys and E. canis were higher (P = .015) than those of seronegative dogs. A. platys DNA was amplified from 7/21 (33%) A. platys seroreactive dogs and from 1 E. canis seroreactive dog; E. canis DNA was amplified from 21/25 (84%) E. canis seroreactive dogs. E. canis DNA was amplified most often from blood, whereas A. platys DNA was amplified most often from bone marrow.Conclusions and Clinical ImportanceApparently healthy, free‐roaming dogs coseropositive for A. platys and E. canis may have increased intraoperative bleeding tendencies despite normal hemostatic parameters. Future investigations should explore the potential for vascular injury as a cause for bleeding in these dogs. Improved tick control is needed for dogs in Grenada.

In vitro effects of Yunnan Baiyao on canine hemangiosarcoma cell lines.

Yunnan Baiyao is a Chinese herbal medicine that has been utilized for its anti-inflammatory, haemostatic, wound healing and pain relieving properties in people. It has been utilized in the veterinary profession to control bleeding in dogs with hemangiosarcoma (HSA) and has been anecdotally reported to prolong survival times in dogs with this neoplasm. This study evaluated the in vitro activity of Yunnan Baiyao against three canine HSA cell lines after treatment with increasing concentrations of Yunnan Baiyao (50, 100, 200, 400, 600 and 800 µg mL(-1) ) at 24, 48 and 72 h. Mean half maximum inhibitory concentration (IC50 ) at 72 h for DEN, Fitz, SB was 369.9, 275.9 and 325.3 µg mL(-1) , respectively. Caspase-3/7 activity increased in correlation with the IC50 in each cell line which was confirmed by the terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL, APO-BRDU Kit; BD Biosciences, San Jose, CA, USA) assay. VEGF in cell supernatant was also quantified. Overall, the study found that Yunnan Baiyao causes dose and time dependent HSA cell death through initiation of caspase-mediated apoptosis, which supports future studies involving Yunnan Baiyao.

Intravenous administration of desmopressin acetate to reverse acetylsalicylic acid‐induced coagulopathy in three dogs

Acetylsalicylic acid (ie, aspirin) administration inhibits platelet aggregation in dogs and is associated with increased perioperative blood loss and transfusion requirements in people. Desmopressin acetate (DDAVP) is used to control or prevent bleeding in dogs with type 1 von Willebrand disease and is also widely reported in the human literature as an emergency antithrombotic reversal agent. Three dogs undergoing surgery for intervertebral disc disease had marked prolongations in buccal mucosal bleeding time (BMBT) after aspirin administration. DDAVP was given intravenously preoperatively and achieved prompt reversal of the prolongation in BMBT. None of the dogs experienced intraoperative bleeding complications. IV DDAVP corrected prolongations in BMBT in dogs given aspirin and should be considered in dogs requiring prompt reversal of aspirin-induced coagulopathies to reduce the risk of bleeding complications.

A novel hemostatic sealant composed of gelatin, transglutaminase and thrombin effectively controls liver trauma-induced bleeding in dogs

novel hemostatic sealant based on the in situ gel formation of gelatin catalyzed by thrombin and crosslinked by transglutaminase was designed. The aim of this study was to investigate the efficacy of the hemostatic sealant in control of bleeding caused by liver trauma in dogs. Hepatic trauma that mimicked the grade III-IV rupture of liver was made in 20 dogs. The traumatic lesion was topically administered the hemostatic sealant (treatment group, n=10), or a thrombin solution (control group, n=10). The time to achieve hemostasis and the blood loss were measured. Contrast-enhanced ultrasound (CEUS) examination was performed in each animal on d 3, d 7, and d 10 d postoperatively to study the healing of the lesions. The mean time to achieve hemostasis in the treatment group was significantly shorter than that in the control group (1.20±0.33 vs 6.70±0.64 min, P<0.05). The mean blood loss in the treatment group was significantly less than that in the control group (47.22±8.61 vs 79.29±11.97 mL, P<0.05). In CEUS examination, the traumatic lesions in the treatment group became significantly smaller on d 3, and disappeared on d 7, whereas the lesions in the control group still existed on d 10. Ascites were never found during 10 d follow-up in the treatment group but were observed on d 3 and d 7 in the control group. Compared with thrombin, the novel hemostatic sealant shows much better efficacy in hemostasis and may promote wound healing in dog liver trauma.

Sensitivity of whole blood clotting time and activated partial thromboplastin time for factor IX: relevance to gene therapy and determination of post‐transfusion elimination time of canine factor IX in hemophilia B dogs

The purpose of this study was to determine the detection threshold of two clotting tests to minute quantities of factor (F) IX in the canine hemophilia B system: the whole blood clotting time (WBCT) and the activated partial thromboplastin time (aPTT). To our knowledge, the relative sensitivity of these tests for minute amounts of canine FIX has not been previously published. As these tests are relatively easy and quick to perform, they are useful and important for determining when infused FIX has been cleared, correctly identifying onset and estimating level of transgene expression in gene transfer experiments, and detecting inhibitory antibodies to FIX. The WBCT was sensitive to as little as 0.01% FIX (Fig. 1A). The estimated level of canine FIX in normal dogs is 5 μg mL−1, thus 0.01% is estimated to be 0.5 ng FIX per mL plasma [1]. The sensitivity of the aPTT to canine FIX was 0.1%, estimated to be 5 ng mL−1 (Fig. 1B). As no activator is used with the WBCT, these data suggest coagulation assays are more sensitive to canine FIX with less activation of the coagulation system. Transfused canine FIX shortened the aPTT for an average of 12 days (range 8–17 days) and the WBCT for an average of 22 days (range 14–27 days). This difference is most likely due to the differences in sensitivity of these two assays. These data provide a reference time-point after which transfused FIX that has not yet been cleared can be distinguished from expressed FIX resulting from successful gene transfer experiments. Fig. 1 (A). Effect of canine factor (F) IX on the WBCT in hemophilia B dog blood. The addition of 0.01% canine FIX significantly shortened the WBCT (heavy line) from baseline (*P = 0.039). (B) Effect of canine FIX on the activated partial thromboplastin time ... A test for the delayed clotting of whole blood in severe hemophilia was first described by Wright [2] over a century ago. The original directions of Lee and White [3] in 1913 for the WBCT are now obsolete, and many modifications have been made, including the use of siliconized test tubes to prevent activation of the clotting system [4]. Careful collection of blood samples is essential if consistency in the WBCT values is to be obtained with replicate testing [5]. In contrast to other tests, the WBCT is relatively insensitive to plasma FIX levels above about 3-5% of normal (Fig. 1A). Hence patients with moderate or mild hemophilia may have a normal WBCT even during bleeding episodes [6]. While quite useful in preclinical animal studies, the WBCT tests are infrequently used in diagnosis and monitoring of therapy in humans. The advent of gene therapy in canine hemophilia B has indicated the need for readily available clotting tests that are sensitive to low levels of plasma FIX activity and can be easily repeated over years of follow-up [7]. Additionally, sudden prolongation of the WBCT has been a harbinger of inhibitory antibodies to canine FIX [8]. The hemophilia B dogs require frequent plasma FIX therapy to treat spontaneous bleeding [9,10] and, following invasive procedures, to prevent hemorrhage and facilitate wound healing [11]. Residual plasma FIX post-transfusion was detectable by aPTT for 8–17 days and the WBCT for 14–27 days (Fig. 1C). This late phase of clearance may indicate a change in kinetics of elimination of FIX, influenced perhaps by a slow return to the blood stream of procoagulants. This is especially relevant to FIX that is known to bind to type IV collagen via lysine at position 5 or valine at position 10 [12-15]. Notably, FIX variants mutated at these sites have increased circulating levels of FIX [16]. The animal that required the longest period of time (27 days, Fig. 1C) for the WBCT to return to basal values had a partial hepatectomy and received the largest dose of FIX replacement therapy, suggesting but not proving that dose of FIX may be a factor in the late phase of elimination [17]. Other canine FIX activity assays include FIX bioassay by two-stage [18] and chromogenic methods [19]. In general, these assays are used to detect FIX levels of 1% or greater and are difficult to reliably standardize for levels lower than 1%. A canine FIX ELISA has also been established for determining protein levels [1,20,21]. All three of these assays are quantitative and require considerable laboratory time and expertise. In contrast, the WBCT and the aPTT, while qualitative, can be performed rapidly and are quite sensitive to small amounts of canine FIX that can give an early readout on how to interpret gene transfer and protein replacement experiments for inhibitors.

Effect of paracetamol coadministration on aspirin-induced gastrointestinal bleeding in dogs.

Journal Article Effect of paracetamol coadministration on aspirin-induced gastrointestinal bleeding in dogs Get access J L Leeling, J L Leeling Toxicology Department, Miles Laboratories, Inc., P.O. Box 40, Elkhart, Indiana 46515, USA Toxicology Department, Miles Laboratories, Inc., P.O. Box 40, Elkhart, Indiana 46515, U.S.A. Search for other works by this author on: Oxford Academic Google Scholar N Johnson, N Johnson Toxicology Department, Miles Laboratories, Inc., P.O. Box 40, Elkhart, Indiana 46515, USA Search for other works by this author on: Oxford Academic Google Scholar R J Helms R J Helms Toxicology Department, Miles Laboratories, Inc., P.O. Box 40, Elkhart, Indiana 46515, USA Search for other works by this author on: Oxford Academic Google Scholar Journal of Pharmacy and Pharmacology, Volume 33, Issue 1, September 1981, Pages 61–62, https://doi.org/10.1111/j.2042-7158.1981.tb13709.x Published: 12 April 2011 Article history Received: 28 July 1980 Published: 12 April 2011