Radio-ulnar ischaemic necrosis in 14 dogs

To characterise signalment, imaging features and any associated clinical findings of dogs with a radiographic diagnosis of radio-ulnar ischaemic necrosis.

Retrospective case series reviewing medical records (2010 to 2024) of dogs with imaging lesions consistent with a radio-ulnar ischaemic necrosis on computed tomography or digital radiographs.

Fourteen dogs had a radiographic radio-ulnar ischaemic necrosis on at least one limb.

All dogs identified were adult dogs (1 to 12 years), with Spaniels and their crosses most common (8/14), followed by three Terriers, one Labrador cross, one English Bulldog and one beagle cross. Two dogs had radio-ulnar ischaemic necrosis identified incidentally and were not lame. Twelve dogs were lame, with the majority having another coexisting cause of lameness identified. Two dogs, however, presented for lameness without another likely cause other than the presence of radio-ulnar ischaemic necrosis, and one dog suffered a radio-ulnar ischaemic necrosis associated pathological fracture. Two variants of radio-ulnar ischaemic necrosis were described: the classically described RUIN and an "atypical" monostotic lesion, with one dog having one of each. Radio-ulnar ischaemic necrosis lesions were all identified in the proximal third of the antebrachium.

Radio-ulnar ischaemic necrosis is seen in a variety of breeds and may be more common in Spaniels. They may be bilateral or unilateral, classic or monostotic. Radio-ulnar ischaemic necrosis lesions may be an incidental or more rarely direct cause of lameness or pathological fracture. As half the population had bilateral RUIN, a non-trauma-related inciting cause of the nutrient vascular ischaemia is possible.