Introduction

Feline arterial thromboembolism (FATE) represents a life-threatening disease. There are different protocols published concerning thrombolytic therapy in this indication. Reteplase is a third-generation tissue plasminogen-activator used in people as bolus injection for thrombolysis, which has not yet been described in cats.

Methods

This retrospective observational study examines the use of reteplase as therapy for feline arterial thromboembolism. In cats presented with arterial thromboembolism, reteplase was applied with a dosage of 1 unit per cat every 8 hours until there were signs of regain of perfusion in the affected legs. Application of reteplase was stopped respectively interrupted if imminent reperfusion injury was suspected or bleeding occurred. Cats were additionally treated with enoxaparin, clopidogrel, analgesia and cardiac therapy as needed. Medical data of these cats were reviewed and evaluated concerning success and complications. Data were analyzed with a commercial statistical software program.

Results

Twelve cats were included in this study between December 2018 and November 2020. The most common breed was domestic shorthair in 9/12 cats. Nine animals were male-castrated, one was male and two were female-spayed. The mean age was 9.8 years (standard deviation [SD]: 3.3 years). Mean weight was 5.1 kg (SD 1.5 kg). In 10/12 cases, FATE was caused by cardiac disease. Chest radiographs of two other cats were suspicious for pulmonary neoplastic disease, additionally one of these cats had cardiomyopathy with left atrial dilation. In 8 of 12 cats both hind legs were affected, in 3 cats the left foreleg and in one cat the right hind leg. A median amount of 5 units reteplase per cat was applied over time (range 1–13). Hyperkalemia (≥5.0 mmol/l) was not detected in any of the patients. Most cats showed a drop of hematocrit during the hospital stay, anemia with a hematocrit below 20% was detected in 2/12 patients. Overall, 9/12 cats and 7/8 cats with both hind legs affected were treated successfully and discharged from the hospital.

Conclusion

Reteplase appears to be a promising therapy in the treatment of FATE and although no evidence of reperfusion injury was noted, larger prospective studies are needed to confirm these findings.

E-mail: Esther.Hassdenteufel@vetmed.uni-giessen.de