Persistent hypercoagulability in dogs envenomated by the European adder (Vipera berus berus).

BACKGROUND: Envenomation by the European adder, Vipera berus berus (Vbb), is a medical emergency. The overall in vivo haemostatic effects of pro- and anticoagulant components in Vbb venom, and the downstream effects of cellular injury and systemic inflammation, are unclear. OBJECTIVES: To longitudinally describe the global coagulation status of dogs after Vbb envenomation and compare to healthy controls. A secondary aim was to investigate differences between dogs treated with and without antivenom. METHODS: Citrated plasma was collected at presentation, 12 hours (h), 24 h, 36 h and 15 days after bite from 28 dogs envenomated by Vbb, and from 28 healthy controls at a single timepoint. Thrombin generation (initiated with and without exogenous phospholipids and tissue factor), thrombin-antithrombin (TAT)-complexes and the procoagulant activity of phosphatidylserine (PS)-expressing extracellular vesicles (EVs), expressed as PS-equivalents, were measured. RESULTS: At presentation the envenomated dogs were hypercoagulable compared to controls, measured as increased thrombin generation, TAT-complexes and PS-equivalents. The hypercoagulability decreased gradually but compared to controls thrombin generation and PS-equivalents were still increased at day 15. The discrepancy in peak thrombin between envenomated dogs and controls was greater when the measurement was phospholipid-dependent, indicating that PS-positive EVs contribute to hypercoagulability. Lag time was shorter in non-antivenom treated dogs, compared to antivenom treated dogs <24 h after envenomation. CONCLUSIONS: Hypercoagulability was measured in dogs up to 15 days after Vbb envenomation. Dogs treated with antivenom may be less hypercoagulable than their non-antivenom treated counterparts. Thrombin generation is a promising diagnostic and monitoring tool for Vbb envenomation.

Evaluation of Urinary Clusterin and Cystatin B as Biomarkers for Renal Injury in Dogs Envenomated by the European Adder (Vipera berus).

Dogs are commonly bitten by the European adder (Vipera berus) but studies investigating the effects of envenomation are limited. Snakebite-related kidney injury is reported in dogs but diagnosis of acute kidney injury (AKI) might be limited by the insensitivity of routinely used renal function biomarkers. The aim of this study was to evaluate novel biomarkers of renal injury (urinary cystatin B and urinary clusterin) and biomarkers of renal function (serum creatinine and serum symmetric dimethylarginine), and urine protein to creatinine ratio in dogs envenomated by V. berus. Biomarkers were measured at presentation (T1), 12 hours (T2), 24 hours (T3), 36 hours (T4), and 14 days (T5) after snakebite and compared to a group of healthy control dogs. A secondary aim was to investigate the association between biomarker concentrations and severity of clinical signs of envenomation using a snakebite severity score (SSS). Urinary cystatin B concentrations were significantly higher at all timepoints in envenomated dogs compared to controls (P < .010), except for T5 (P = .222). Absolute urinary clusterin concentrations were not significantly different to controls at any timepoint. Compared to controls, serum creatinine and serum symmetric dimethylarginine concentrations were significantly lower in envenomated dogs at T1-T4 (P < .036) and T2-T4 (P < .036), respectively. Urine protein to creatinine ratio was higher in envenomated dogs compared to controls at T2 and T3. Urinary cystatin B concentrations at T1 were correlated with SSS (Spearman's ρ = 0.690, P < .001). The increased urinary cystatin B concentrations observed in dogs envenomated by V. berus in comparison to controls may indicate renal tubular injury in these patients.

Serial serum creatinine, SDMA and urinary acute kidney injury biomarker measurements in dogs envenomated by the European adder (Vipera berus).

BACKGROUND: Acute kidney injury (AKI) is associated with high morbidity and mortality in dogs, but diagnosis may be impaired due the insensitivity of routine renal function biomarkers to detect earlier or milder forms of injury. Snake envenomation is one of several causes of AKI in dogs and humans. Dogs are commonly envenomated by the European adder (Vipera berus) between April and October each year, but few studies exist examining serial serum creatinine (sCr) and symmetric dimethylarginine (SDMA) measurements and AKI biomarkers in these dogs. Novel urinary biomarkers could improve clinical outcome by allowing earlier diagnosis of and intervention in AKI. The aim of this study was to assess the presence of AKI in dogs envenomated by V. berus at 12, 24 and 36 h after bite, as well as 14 days later, using sCr, SDMA and a panel of urinary AKI biomarkers normalised to urine creatinine (uCr), compared to a group of healthy control dogs. RESULTS: Thirty-five envenomated dogs and 35 control dogs were included. Serum creatinine did not exceed the upper reference limit at any time point in any dog after envenomation. Serum SDMA did not exceed 0.89 µmol/L in any dog. Compared to controls, urinary albumin/uCr, neutrophil gelatinase-associated lipocalin/uCr and monocyte chemotactic protein-1/uCr were significantly elevated 12 h (P <  0.0001, P <  0.0001, P = 0.01), 24 h (P <  0.001, P <  0.001, P = 0.002) and 36 h (P <  0.001, P <  0.001, P = 0.0008) after bite. Osteopontin/uCr was higher 24 and 36 h after bite (P < 0.0001), kidney injury molecule-1/uCr, interleukin-8/uCr and γ- glutamyl transferase/uCr were significantly higher 36 h after bite (P = 0.003, P = 0.0005, P = 0.001). Urinary cystatin C/uCr was not significantly different to controls at any timepoint. Biomarker/uCr ratios were not significantly different 14 days after envenomation compared to controls. CONCLUSION: Urinary biomarker/Cr ratios are indicative of mild transient, non-azotaemic AKI in dogs envenomated by V. berus.

Ambulatory electrocardiography and serum cardiac troponin I measurement in 21 dogs envenomated by the European adder (Vipera berus).

BACKGROUND: Envenomation by the European adder (Vipera berus) is common in dogs in Europe. Cardiac arrhythmias occur but clinical studies of envenomated dogs are limited. OBJECTIVES: To describe arrhythmias in dogs within 48 hours of envenomation, and investigate associations between arrhythmia grade, serum troponin I (cTnI), and snakebite severity score (SS score). ANIMALS: Twenty-one client-owned dogs bitten by V berus. METHODS: Prospective cohort study of envenomated dogs. Ambulatory electrocardiograms were recorded from presentation to 48 hours after snakebite, and arrhythmias graded 0 to 3 based on frequency and severity. Serum cTnI was measured at presentation, 12 hours, 24 hours, 36 hours, and 14 days after bite. An SS score of 1 to 3 was recorded at admission and based on clinical examination. RESULTS: All dogs survived. Twelve dogs (57%) developed arrhythmias, all of which were ventricular in origin. Severe complex ventricular arrhythmias (VAs) were observed in 6 dogs (29%). Eighty-one percent of dogs (n = 17) had increased cTnI concentrations at 1 or more time points. Dogs that developed arrhythmias had significantly higher concentrations of cTnI at 12 hours (1.67 [0.04-32.68] versus 0.03 [0.01-0.052]; P = .002), 24 hours (1.88 [0.2-14.23] versus 0.06 [0.01-2.06]; P = .009), and 36 hours (3.7 [0.02-16.62] versus 0.06 [0.01-1.33]; P = .006) after bite compared to those that did not. Contingency table analysis showed that SS score was not significantly associated with arrhythmia grade (P = .9). CONCLUSIONS AND CLINICAL IMPORTANCE: Myocardial cell injury, reflected by increased cTnI concentrations and VAs, is common after V berus envenomation in dogs. Prolonged electrocardiography monitoring is advised, particularly where cTnI is increased.