Application of real-time ultrasonography for the detection of tarsal vein thrombosis in cattle.

The clinical and ultrasonographic features of the thrombosis of three tarsal veins in a six-year-old dairy cow are described. Thrombosis and metastatic abscessation developed on the left tarsus six days after the amputation of the lateral claw of the left hindlimb. Originally, the cow suffered from a severe purulent arthritis of the distal interphalangeal joint and a retroarticular abscess, caused by interdigital necrobacillosis. By means of real-time ultrasonography, using a 7.5 MHz transducer, a marked subcutaneous oedema, a subcutaneous abscess, and a thrombosis of the ramus cranialis and ramus caudalis of the vena saphena lateralis reaching the confluence into the vena saphena lateralis and a thrombosis of the ramus caudalis of the vena saphena medialis could be identified. The thrombosed veins were not compressible, were oval and had an increased diameter of up to 9 x 12 mm. Intraluminal masses were visualised as hypoechoic structures and the veins distal to the thrombosis were distended up to 10 x 13 mm. The differential diagnosis and pathogenesis of the thrombosis and the abscessation are discussed, and the clinical course and the sonographic observations of the thrombosis during a six week period are described.