The use of 4-dimensional magnetic resonance angiography as a noninvasive procedure to diagnose subclavian steal syndrome in a dog.

CASE DESCRIPTION

A 5-year-old 4.1-kg (9.0-lb) spayed female Toy Poodle was referred because of a 6-month history of sporadic signs of neck pain.

CLINICAL FINDINGS

Diagnostic imaging with MRI and CT revealed a dilated radicular artery connecting the right and left vertebral arteries and causing mild compression of the spinal cord. The left subclavian artery caudal to the origin of the left vertebral artery was absent. Subclavian steal syndrome (SSS) was suspected.

TREATMENT AND OUTCOME

The owner declined surgical treatment; thus, the dog was treated conservatively with glucocorticoids and analgesics. Eight months later, the dog's clinical signs were unchanged but palliated with the administration of glucocorticoids and analgesics, and 4-dimensional (4-D) magnetic resonance angiography (MRA) revealed that the left vertebral artery received blood supply from the right vertebral artery through the dilated radicular artery and that the left vertebral artery caudal to this site had retrograde flow and drained into the left subclavian artery, confirming the diagnosis of SSS. The owner again declined surgery, and conservative treatment continued. The dog's condition was unchanged at the last follow-up communication 11 months after 4-D MRA.

CLINICAL RELEVANCE

Subclavian steal syndrome is an extremely rare condition in dogs, and our findings suggested that 4-D MRA could be used to definitively diagnose SSS in dogs.