Concurrent Epistaxis, Retinal Bleeding and Hypercoagulability in a Dog with Visceral Leishmaniosis

Canine visceral leishmaniosis (CVL) caused by Leishmania infantum is a common endemic zoonotic disease in the Middle East, including Israel. The common clinical signs, include, among others, ocular lesions and epistaxis. This report describes a case of CVL in a Boxer dog, which was presented to the hospital due to severe epistaxis, retinal hemorrhage, detachment and uveitis. The platelet count and platelet-crit were increased, and the clotting times were normal. Thromboelastometry demonstrated marked hypercoagulability. The bleeding tendency in this dog was therefore present concurrently with a hypercoagulable state and was likely a result of vasculitis secondary to circulating immune complex (CIC) deposition, which probably interfered with the platelet-vascular endothelium interactions. The dog improved with systemic prednisone and allopurinol therapy, as well as topical ophthalmic treatment. No bleeding episodes were noted from the time treatment was initiated. Nevertheless, the dog remained hypercoagulable during the follow-up period. Epistaxis and retinal hemorrhages in dogs with CVL may result from platelet dysfunction and thrombocytopenia, as previously reported. Nevertheless, based on the present findings, we suggest that in a subset of such cases, when thrombocytopenia is absent and hypercoagulability is demonstrated, bleeding may occur secondary to vasculitis. Thromboelastomety is therefore indicated in dogs with CVL, even in cases showing a bleeding tendency.