Hypertrophic osteopathy associated with aortic thrombosis in a dog

Background: Aortic thrombosis (ATh) is an uncommon problem in dogs. Although the pathogenesis of hypertrophic osteopathy (HO) is unknown, it is thought this can be due to blood flow disorder. In this case, removal of aortic thromboembolism (ATE) resulted in periosteal proliferation. Case description: A 4.8-kg, 3-year-old, intact female Maltese was referred with a bite wound showing pneumomediastinum, pneumothorax, and subcutaneous emphysema. After adequate treatment, the dog had recovered well and was discharged. Findings/treatment and outcome: Acute non-painful paraparesis suddenly developed 5 days after discharge. An abdominal ultrasound showed ATE at the level of 1 cm proximal to the external iliac arterial bifurcation. Based on clinical sign, physical exam, neurologic exam, and ultrasonography, ATh was diagnosed. Arterial thrombectomy was performed to remove the thrombus. Twenty-four days after surgery, the dog had pain and soft tissue swelling of both stifles due to HO. After rehabilitation, the dog finally started to ambulate, and the dorsal pedal arteries pulse was normal. Hypertrophic osteopathy also resolved completely. Conclusion: This report suggests the relationship between HO and ATh, for the first time in veterinary medicine.