Objective

To describe systemic administration of tissue plasminogen activator (TPA) in dogs and cats.

Methods

Single academic center retrospective study (2010–2020). Inclusion criteria were dogs or cats who received systemic TPA injection through an intravenous catheter to thrombolyse a distant known/suspected thrombus. Data collected included demographics, factor(s) predisposing to thrombus formation, TPA dosing regimen, location of known/suspected thrombus, clinicopathologic and diagnostic imaging data, clinical response to thrombolysis, complications and outcome. Descriptive statistics were used. Outcome and complication rates were compared between species using Fisher exact test.

Results

Fifteen dogs and 5 cats received a total of 26 and 6 injections respectively. Mean age for dogs was 4.3±5.7 years. Predisposing factors included tricuspid valve surgical repair under cardiopulmonary bypass (n=6), no know factors (n=3), nephropathy with concurrent hyperadrenocorticism (n=1), nephropathy (n=1), patent ductus arteriosus surgical repair (n=1), atrioventricular septal defect surgical repair (n=1), disseminated intravascular coagulopathy secondary to pancreatitis (n=1) and hepatic abscessation (n=1). Thrombus location included pulmonary thromboembolism (n=6), intracardiac thrombus (n=5), cranial vena cava thrombus (n=2), aortic thrombus (n=1) and femoral and iliac thrombus (n=1). The average TPA dose was 0.7±0.5 mg/kg. The median time between diagnosis/suspicious of thrombus and the first dose was 24.5 hours (3–150). Complication rate was 13% and included epistaxis (n=1) and epistaxis and bruises (n=1). Clinical improvement and/or clot resolution occurred in 73% of cases. Discharge rate was 73%.

Median age for cats was 9 years (3–15). All cats had underlying cardiomyopathy and suffered from thrombus in the right forelimb (n=2), bilateral pelvic limbs (n=2) and right renal artery (n=1). The average TPA dose was 1.0 mg/kg (0.9–1.4). The median time between diagnosis of thrombus and the first dose was 4 hours (2–17). Two cats were azotemic at admission, which persisted. Sixty percent of cats developed complications with treatment, which included reperfusion injury (n=1), acute kidney injury (n=1) and both acute kidney/reperfusion injuries (n=1). Discharge rate was 40%. There was no evidence of difference in complication or discharge rates between species (p=0.07 and 0.290 respectively).

Conclusions

Thrombolysis with systemic TPA seems to be safe and effective in dogs. It requires more investigation in cats.

Disclosures

No disclosures to report.