Proximal Gastrocnemius Musculotendinopathy in Dogs: A Retrospective Computed Tomography-Based Study.

Area of Science:

• Veterinary Radiology
• Canine Musculoskeletal Imaging
• Diagnostic Imaging

Background:

• Proximal gastrocnemius musculotendinopathy causes chronic hindlimb lameness in athletic dogs.
• Accurate diagnosis is crucial for effective management and to avoid misdiagnosis of other stifle pathologies.

Purpose of the Study:

• To describe the computed tomography (CT) features of proximal gastrocnemius musculotendinopathy in dogs.
• To compare clinical presentation, associated lesions, and outcomes with existing literature.

Main Methods:

• Retrospective analysis of 24 dogs diagnosed with proximal gastrocnemius musculotendinopathy via contrast-enhanced CT.
• Evaluation of signalment, clinical signs, concurrent disorders, imaging findings, treatments, and outcomes.
• Comparison with published magnetic resonance imaging (MRI) and radiography studies.

Main Results:

• Active working breeds, particularly Border Collies, were most affected.
• Chronic hindlimb lameness was the primary clinical sign.
• CT revealed characteristic soft tissue swelling and contrast enhancement at the lateral gastrocnemius head origin.
• Concurrent cranial cruciate ligament rupture or lumbosacral stenosis occurred in 58% of cases.
• Conservative treatment yielded favorable outcomes in 14 of 17 dogs.

Conclusions:

• CT provides valuable diagnostic information for proximal gastrocnemius musculotendinopathy, despite MRI's superior soft tissue detail.
• Early CT recognition aids in differentiating this condition from cranial cruciate ligament injuries, potentially avoiding unnecessary stifle surgery.