Hemorrhagic, Hemostatic, and Thromboelastometric Disorders in 35 Dogs with a Clinical Diagnosis of Leptospirosis: A Prospective Study

Evaluation of coagulation profile in dogs with ACTH-dependent hyperadrenocorticism compared to healthy dogs by rotational thromboelastometry (ROTEM)

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 ×103/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.

Updated ACVIM consensus statement on leptospirosis in dogs

Since publication of the last consensus statement on leptospirosis in dogs, there has been revision of leptospiral taxonomy and advancements in typing methods, widespread use of new diagnostic tests and vaccines, and improved understanding of the epidemiology and pathophysiology of the disease. Leptospirosis continues to be prevalent in dogs, including in small breed dogs from urban areas, puppies as young as 11 weeks of age, geriatric dogs, dogs in rural areas, and dogs that have been inadequately vaccinated for leptospirosis (including dogs vaccinated with 2-serovar Leptospira vaccines in some regions). In 2021, the American College of Veterinary Internal Medicine (ACVIM) Board of Regents voted to approve the topic for a revised Consensus Statement. After identification of core panelists, a multidisciplinary group of 6 experts from the fields of veterinary medicine, human medicine, and public health was assembled to vote on the recommendations using the Delphi method. A draft was presented at the 2023 ACVIM Forum, and a written draft posted on the ACVIM website for comment by the membership before submission to the editors of the Journal of Veterinary Internal Medicine. This revised document provides guidance for veterinary practitioners on disease in dogs as well as cats. The level of agreement among the 12 voting members (including core panelists) is provided in association with each recommendation. A denominator lower than 12 reflects abstention of ≥1 panelists either because they considered the recommendation to be outside their scope of expertise or because there was a perceived conflict of interest.

Hemostatic and thromboelastographic parameters in dogs with renal azotemia

Background and Aim

Humans and dogs with azotemia can develop coagulation disorders. Therefore, this study aimed to evaluate the coagulation profiles and thromboelastographic parameters in dogs with acute kidney injury (AKI) and chronic kidney disease (CKD).

Materials and Methods

In this prospective study, 31 client-owned dogs with renal azotemia (creatinine >220 μmol/L) were enrolled. Clinical signs of hemostatic disorders, complete blood count, coagulation profile, D-dimers, thromboelastography, and 28-day survival data were obtained and analyzed using the t-test, Mann-Whitney U test, and Chi-square test. Statistical significance was set at p < 0.05.

Results

Seventeen dogs with AKI, 10 with CKD, and four with acute-on-chronic kidney injury (AoC) were enrolled. Ten dogs (AKI, 8/17; CKD, 2/10) had thrombocytopenia. Prothrombin time was prolonged in four dogs with AKI and longer in dogs with AKI than in dogs with CKD (p = 0.004). The activated partial thromboplastin time was prolonged in 23 dogs (AKI, 14/17; CKD, 7/10; AoC, 3/4) and was longer in azotemic dogs than in healthy control dogs (p = 0.003). Thromboelastographic tracings were hypocoagulable in three dogs with AKI and hypercoagulable in 16 dogs (AKI 4/17, CKD 9/10, AoC 3/4). The thromboelastographic values for maximum amplitude (p < 0.001) and global clot strength (p < 0.001) were lower in dogs with AKI than in those with CKD.

Conclusion

Hypercoagulable thromboelastographic tracings were observed in dogs with CKD, whereas coagulation times were prolonged in dogs with AKI. However these findings should be validated by further studies.

Next Generation Sequencing for Diagnosis of Leptospirosis Combined With Multiple Organ Failure: A Case Report and Literature Review

Introduction

Leptospirosis poses a major threat to human life. The disease spectrum ranges from a nearly undetectable presentation to severe multi-organ dysfunction and death. Leptospirosis is difficult to diagnose by traditional antibody and culture tests. We here present a case of multiple organ failure associated with leptospirosis.

Material and Methods

A 64-year-old woman presented with fatigue and arthralgia, which developed rapidly into multiple organ injuries, and she eventually died of cerebral hemorrhage. Serum antibody test and cultures of blood, sputum, urine, and feces samples were all negative. The patient was diagnosed with leptospirosis by the next-generation sequencing (NGS).

Conclusion

We conclude that leptospirosis is a neglected zoonosis caused by pathogenic Leptospira species. New techniques such as NGS are highlighted for early diagnosis. Surveillance for pathogens during diagnosis can provide guidance for clinical treatment and improves prognosis.

Association of markers of endothelial activation and dysfunction with occurrence and outcome of pulmonary hemorrhage in dogs with leptospirosis

Background

Endothelial dysfunction might contribute to the development of leptospiral pulmonary hemorrhage syndrome (LPHS).

Hypothesis

Serum concentrations of markers of endothelial activation and dysfunction are higher in dogs with leptospirosis and correlate with the occurrence of LPHS and a higher case fatality rate.

Animals

Clinically healthy dogs (n = 31; 10/31 dogs confirmed healthy based on no detected abnormalities on blood work), dogs with leptospirosis with LPHS (n = 17) and without LPHS (n = 15), dogs with acute kidney injury not due to leptospirosis (AKI‐nL, n = 34).

Methods

Observational study. Serum concentrations of soluble intercellular adhesion molecule 1 (sICAM‐1), vascular endothelial growth factor (VEGF), and angiopoietin‐2 (Ang‐2) at admission were compared between groups. Correlations with outcome and the accuracy to predict LPHS were examined.

Results

Soluble intercellular adhesion molecule (sICAM‐1), VEGF, and Ang‐2 concentrations were higher in dogs with AKI‐nL (sICAM‐1 34.7 ng/mL, interquartile range [IQR] = 24.4‐75.5; VEGF 43.1 pg/mL, IQR = 12.3‐79.2; Ang‐2 8.5 ng/mL, IQR = 6.2‐12.3), leptospirosis without LPHS (sICAM‐1 45.1 ng/mL, IQR = 30.6‐59.0; VEGF 32.4 pg/mL, IQR = 12.5‐62.6; Ang‐2 9.6 ng/mL, IQR = 6.9‐19.3), and LPHS (sICAM‐1 69.7 ng/mL, IQR = 42.1‐89.1; VEGF 51.8 pg/mL, IQR = 26.3‐96.7; Ang‐2 8.0 ng/mL, IQR = 5.6‐12.2) compared to controls (P < .001). In dogs with leptospirosis, VEGF and sICAM‐1 were higher in nonsurvivors (sICAM‐1 89.4 ng/mL, IQR = 76.5‐101.0; VEGF 117.0 pg/mL, IQR = 90.3‐232.4) than survivors (P = .004) and sICAM‐1 predicted the development of LPHS.

Conclusions

Soluble intercellular adhesion molecule 1, VEGF, and Ang‐2 do not discriminate leptospirosis from AKI‐nL. In dogs with leptospirosis, sICAM‐1 and VEGF predict outcome and sICAM‐1 might identify dogs at risk for LPHS.

Kidney Injury Molecule-1 in the detection of early kidney injury in dogs with leptospirosis

Renal damage, a common feature in canine leptospirosis, ranges from a subclinical affection to kidney dysfunction and death. Chances of recovery can be improved by early intervention. However, traditional biomarkers (serum urea and creatinine) have limited relevance for precocity. Kidney Injury Molecule-1 (KIM-1) is a transmembrane protein upregulated in early stages of tubular injury. This study evaluated the use of urinary KIM-1 to detect early renal injury in naturally occurring canine leptospirosis. This exploratory research included 30 dogs divided into two groups: (1) dogs with leptospirosis (n = 25) and (2) healthy dogs (n = 5). Leptospira sp. infection was diagnosed through urine PCR and/or direct bacteriologic culture and/or serology (single MAT titters ≥800). Additionally, stage of infection was further characterized in acute and subacute phases based on the onset of clinical symptoms from 3 to 7 days. Urinary KIM-1 (uKIM-1) concentrations were measured in both groups with a commercial canine ELISA kit. uKIM-1 levels were statistically different (P < 0.01) between the studied groups, especially in non-azotemic dogs (P = 0.0042). The biomarker showed 88 % sensibility to diagnosis of kidney injury at> 1.49 ng/mL cut-off. Urine KIM-1 was negatively correlated with urine specific gravity (USG) but accompanied histopathological evidence of renal degeneration, necrosis and regeneration processes, extending information on kidney health. Measurement of KIM-1 in the urine of canine patients was able to detect naturally occurring acute and subacute leptospirosis accompanied by tubular injury in early non-azotemic infections.

Predictors of Fatal Pulmonary Haemorrhage in Dogs Affected by Leptospirosis Approaching Haemodialysis

A retrospective case control study, which aimed to evaluate potential clinical, laboratory and imaging predictors of fatal pulmonary haemorrhage in dogs with Leptospirosis submitted to haemodialysis. The study population was divided in two groups according to the presence (PH) or absence (nPH) of pulmonary haemorrhage. A statistical comparison was performed at hospital admission for clinical (spontaneous bleeding, icterus, and respiratory distress), laboratory (serum creatinine, urea, phosphate, calcium, bicarbonate, bilirubin, AST, ALT, ALKP, GGT, total protein, albumin, glycaemia, sodium, potassium, CRP, RBC, HCT, HGB, WBC, PLT, PT, aPTT, fibrinogen), and pulmonary radiographic findings between the two groups of dogs. At hospital admission, dogs developing pulmonary haemorrhage were more likely to have respiratory distress (p = 0.002), severely elevated serum bilirubin (p = 0.002), AST (p = 0.04), ALT (p = 0.012), ALKP (p = 0.002), reduced serum glycaemia (p = 0.014), and thrombocytopenia (p = 0.04). Respiratory distress and elevated serum bilirubin (≥11.5 mg/dL) were independently associated with increased risk of pulmonary haemorrhage. In conclusion, the presence of respiratory distress at hospital admission is strongly associated (OR 40.9) with increased risk of pulmonary haemorrhage, even though no abnormalities are found at chest radiography.

Comparison of the prothrombin time-derived and Clauss assays for the measurement of plasma fibrinogen in hospitalized dogs

BACKGROUND

Accurate measurement of fibrinogen is necessary for detecting bleeding tendencies and inflammation. The Clauss assay determines fibrinogen concentration from its inverse relationship with thrombin-induced clot times. PT-derived assays determine fibrinogen concentrations from changes in the optical density during a routine prothrombin assay and allow determination of fibrinogen without additional reagents. This method has not been assessed in clinically ill dogs.

OBJECTIVES

We aimed to determine the agreement between the Clauss and PT-derived fibrinogen assays and compare the ability of the assays to predict surgery-associated transfusions and discriminate between dogs with and without bleeding.

METHODS

Retrospective medical record review identified 200 dogs with a variety of underlying diseases with results from both assays. The two assays were compared using Passing-Bablok regression, and the ability of the assays to identify bleeding and predict the need for transfusions was assessed with receiver operating characteristic (ROC) curve analyses.

RESULTS

The PT-derived assay displayed constant (y-intercept, 32 mg/dL; 95% CI 18-41) and proportional (slope, 0.79; 95% CI 0.75-0.82) bias compared with the Clauss assay. The Clauss assay reported lower values than the PT-derived assay at lower fibrinogen concentrations and higher values at higher concentrations. Comparing the area under the ROC curve did not detect significant differences in the ability of the two assays to discriminate between dogs with and without bleeding or predict the need for surgery-associated transfusions.

CONCLUSIONS

The PT-derived and Clauss assays are not interchangeable, and the Clauss assay could be more sensitive to hypofibrinogenemia in dogs.

Abnormal platelet activity in dogs and cats - impact and measurement

Abnormal platelet activity can either lead to bleeding tendencies or inappropriate thrombus formation and can occur secondarily to a wide variety of disease processes, with a range of clinical consequences and severity. This article will discuss the pathophysiology of platelet function abnormalities and consider a logical diagnostic approach applicable to veterinary practice. Recent advances in platelet function testing will then be discussed, with regards to detection of platelet dysfunction and tailoring of pharmacological manipulation. Although many of these tests are still confined to research or academic institutions, techniques for indirectly assessing platelet function are starting to become more widely available. Although we still require further research to develop guidelines for the use of these tests in clinical decision-making, the recent advances in this field are an exciting step forward in being able to detect and manage platelet dysfunction in both primary care and referral practice.

Leptospirosis as an unusual culprit of acute pancreatitis and portal vein thrombosis in a New Yorker

Leptospirosis often takes clinicians by surprise when presenting in urban locations with unusual manifestations. This delays diagnosis and treatment which increases mortality rate. Our case illustrates the importance of taking into account the socioeconomic backgrounds, environmental exposures, and clinical presentations of patients to create a good differential diagnosis.

Hematological and Hemostatic Alterations Associated With a Single Extracorporeal Renal Replacement Therapy in Dogs With Acute Kidney Injury Associated Leptospirosis: A Pilot Study

Extracorporeal renal replacement therapy (ERRT) used in dogs with acute kidney injury (AKI) may be associated with hematological and hemostatic disorders. However, its characteristics are not fully described in dogs. The purpose of this pilot study was to characterize the impact of ERRT on hematological, hemostatic, and thromboelastometric parameters in dogs with AKI. We conducted a prospective observational single cohort study in 10 client-owned dogs with AKI associated leptospirosis undergoing ERRT. Results from the CBC, coagulation tests (prothrombin and activated partial thromboplastin times [aPTT]) and rotational thromboelastometry (TEM; intrinsic TEM [inTEM] and heparinase-based TEM [hepTEM]) were recorded before and after the first ERRT session. Blood abnormalities observed before the ERRT session included thrombocytopenia (10/10), anemia (8/10), leukocytosis (4/10), prolonged aPTT (4/10) and leukopenia (1/10). After ERRT, the platelet count decreased (-25%; P = .012) whereas leukocytes (+15%; P = .046) and aPTT (+24%; P = .006) increased. The clotting time (CT) on inTEM assay and the relative variation of CT based on inTEM and hepTEM profiles increased after the ERRT session (P = .037 and P = .048, respectively). Seven dogs, 2 dogs, and 1 dog were defined as having a normal, hypocoagulable, and hypercoagulable inTEM profile after ERRT, respectively. After ERRT, no hepTEM parameter was significantly different from before treatment. Platelet count, leukocytes, aPTT and CT were altered after the first ERRT session. Beyond the hemostatic abnormalities expected by the use of UFH, thrombocytopenia appears as the only hemostatic change after a single ERRT session in dogs with AKI.

Determination of reference intervals for single vial rotational thromboelastometry (ROTEM) parameters and correlation with plasmatic coagulation times in 49 clinically healthy dogs

The objectives of this prospective study were determination of reference intervals (RI) for rotational thromboelastometry (ROTEM) parameters in single use reagents and to evaluate correlations between plasmatic coagulation times and ROTEM parameters. Blood was sampled from a jugular vein in 49 client-owned healthy dogs and ex-tem S, in-tem S, fib-tem S and ap-tem S parameters, prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen, haematology, blood chemistry and venous blood gas analysis was performed. Determination of RI was performed using Excel add-in Reference Value Advisor and correlations between PT, aPTT and fibrinogen with selected ROTEM parameters were determined by Spearman correlation. Ex-tem S maximum clot firmness (MCF) RI are smaller compared to RI in people and liquid ex-tem in dogs while maximum lysis was comparable to those in people but smaller than previously reported in dogs. A strong correlation was found between fibrinogen measured by Clauss and fib-tem S and in-tem S MCF (r = 0.541, P < .001 and r = 0.610, P < .001, respectively). PT showed a significant but moderate correlation with ex-tem S CT (r = 0.340, P = .030), in-tem S CFT (r = 0.433, P = .003), fib-tem S CT (r = 0.426, P = .009) and ap-tem S CT (r = 0.354, P = .015) while aPTT was not significantly correlated with any of the evaluated parameters. In conclusion, this study provides single use reagent ROTEM parameter RIs that are different from RI determined with liquid reagents. Significant correlations between fibrinogen concentrations measured by Clauss and clot firmness of fib-tem S and in-tem S profiles and between PT and clotting times of all reagents were identified.

Acute kidney injury management using intermittent low efficiency haemodiafiltration in a critical care unit: 39 dogs (2012-2015)

BACKGROUND

Veterinary studies describing acute kidney injury (AKI) management using renal replacement therapy (RRT) are limited and have primarily focused on intermittent haemodialysis in North American populations. European data are lacking, although differences in populations, pathogen and toxin exposure and RRT modalities may exist between Europe and North America. The present study reviewed RRT-managed cases from the intensive care unit (ICU) of VetAgro Sup, Lyon, France, for the period 2012-2015. The aims were to describe a 4-h RRT protocol of intermittent low efficiency haemodiafiltration, population characteristics and outcomes in canine AKI cases requiring RRT and to identify prognostic variables. We defined DeltaCreat/h as the difference between the serum creatinine level after RRT treatment N and that before treatment N + 1 divided by the time between treatments (in hours).

RESULTS

Thirty-nine dogs were included, and 67% were males. The median (range) age, weight, hospitalization length and number of RRT treatments were 4.4 (0.25-15) years, 26.6 (6.7-69) kg, 8 (1-23) days and 3 (1-8) treatments, respectively. The main AKI causes were leptospirosis (74.4%) and nephrotoxins (15.4%). Age (4.0 vs 5.4 years; P = 0.04), admission urine output (0.5 mL/kg/h vs 0 mL/kg/h; P = 0.02) and hospitalization length (10 vs 4 days; P < 0.001) differed between survivors and non-survivors. Hospitalization length [odds ratio (OR) = 0.4], number of treatments (OR = 5.1), serum potassium level on day 2 (OR = 1.9), DeltaCreat/h between the first and second treatments (OR = 1.2), and UOP during hospitalization (OR = 0.2) were correlated with outcome. The main causes of death were euthanasia (44%) and haemorrhagic diatheses (33%). The overall survival rate was 54%, with 55% of survivors discharged with a median creatinine < 240 µmol/L.

CONCLUSIONS

This is the first description in the veterinary literature of a 4-h protocol of intermittent low efficiency haemodiafiltration to provide RRT in a veterinary critical care unit. While this protocol appears promising, the clinical application of this protocol requires further investigation. Among parameters associated with survival, UOP and DeltaCreat/h between the first and second RRT treatments may be prognostic indicators. The applicability of these parameters to other populations is unknown, and further international, multicentre prospective studies are warranted to confirm these preliminary observations.

Hypocoagulability and Platelet Dysfunction Are Exacerbated by Synthetic Colloids in a Canine Hemorrhagic Shock Model

Background: Hemorrhagic shock and volume replacement can alter coagulation. Synthetic colloids, hydroxyethyl starch (HES), and gelatin, may enhance hypocoagulability. Our primary objective was to describe the effect of four fluid products on coagulation in canine hemorrhagic shock. Our secondary objective was to compare measurements of coagulation during shock to baseline in all dogs.

Methods: Anesthetized greyhounds subjected to atraumatic hemorrhage for 60 min were administered 20 mL kg⁻¹ of either fresh whole blood (FWB), 6% HES 130/0.4, 4% succinylated gelatin (GELO), or 80 mL kg⁻¹ of isotonic crystalloid over 20 min (n = 6 per group). Platelet closure time (PCT), rotational thromboelastometry (ROTEM) and plasma coagulation assays were measured at baseline, end of hemorrhage (shock), and 40 (T60), and 160 (T180) min after study fluid. ROTEM parameters included clotting time (CT), clot formation time (CFT), alpha angle, maximum clot firmness (MCF), lysis index at 60 min (LI60), and thrombodynamic potential index (TPI) for INTEM, EXTEM, FIBTEM (MCF only), and APTEM (LI60 only) profiles. Plasma coagulation assays included prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen concentration and activities of factor VII (FVII), factor VIII (FVIII), and von Willebrand Factor antigen (vWF). Between-group differences were tested using linear mixed models with post-hoc between-group comparisons (Bonferroni-Holm corrected). Differences between baseline and shock were tested using paired t-tests. Significance was set at P < 0.05.

Results: GELO showed longer PCT at T60, compared with FWB and CRYST, and at T180, compared with all other groups. HES showed longer EXTEM CT at T60, compared with all other groups. HES showed lower INTEM and EXTEM MCF at T60 and lower INTEM MCF at T180, compared with FWB. Some plasma coagulation assays showed greater hypocoagulability with HES. Comparing shock to baseline, EXTEM CT, INTEM CFT, EXTEM CFT, PT, and FVIII significantly increased and PCT, INTEM CT, INTEM MCF, EXTEM MCF, EXTEM LI60, EXTEM TPI, FIBTEM MCF, APTT, fibrinogen, FVII, and vWF significantly decreased.

Conclusions: In dogs with hemorrhagic shock, volume replacement with GELO caused mild platelet dysfunction and HES was associated with coagulation changes consistent with hypocoagulability, beyond effects of hemodilution. Shock alone produced some evidence of hypocoagulability.