Canine leishmaniasis with nephrotic syndrome and aortic and caudal vena cava thromboembolism

Objective– To describe a case of leishmaniasis associated with nephrotic syndrome and aortic and caudal vena cava thrombosis in a dog. Case Summary– A 3‐year‐old male Boxer was referred to the Faculty of Veterinary Medicine, Lisbon, with vomiting, polyuria, polydipsia, lethargy, anorexia, and weight loss. On admission, the dog was thin, quiet, and dehydrated. Initial laboratory abnormalities were compatible with a diagnosis of leishmaniasis (confirmed by serology and bone marrow aspirate), and nephrotic syndrome. Three days later, the animal developed lumbar pain, paraparesis, and absent femoral pulses. Coagulation tests showed a marked reduction in antithrombin (AT) and a mild increase in serum fibrinogen concentration. A diagnosis of thromboembolism was made. In spite of treatment aimed at controlling the primary condition and decreasing further thrombus formation, necrosis developed in the distal right pelvic limb and the nail beds of the left pelvic limb. Against medical advice, medication was stopped and, 15 days later, the dog returned to the hospital, showing extensive necrosis of both pelvic limb extremities. Euthanasia was performed at the owner's request. Necropsy showed a thrombus localized at the distal aorta and extending into the right iliac artery, and an additional thrombus extending from both femoral veins onto the caudal vena cava. New or Unique Information Provided– Thromboembolic disease is rare in dogs with leishmaniasis with nephrotic syndrome. This case suggests that a marked decrease in AT and a mild increase in serum fibrinogen may elicit a hypercoagulable state in these patients.