Persistent Right Forelimb Lameness

Case Study: Saddlebred with Persistent Right Forelimb Lameness

Signalment:
15-year-old Saddlebred

History:
The referring veterinarian reported a 1- to 2-month history of right forelimb (RF) lameness. A palmar digital (PD) nerve block improved lameness by approximately 60%. Radiographs of the distal limb revealed mild osteoarthritis in the pastern and coffin joints, along with extensor process remodeling. The horse was treated with intra-articular (IA) steroid injections in the coffin joint but showed no improvement, prompting referral for an objective lameness evaluation and standing CT.

Lameness Examination:

  • Mild to moderate RF lameness observed and measured

  • Significant pain with strong passive flexion of the RF distal limb

  • Mild bilateral fetlock effusion (R >> L)

  • RF distal limb pain with passive flexion (no pain in LF)

  • Otherwise normal limb examination

Following the CT scan, the RF fetlock joint was blocked, resulting in a significant improvement in lameness (68-80%).

Diagnosis & Treatment:
CT revealed an abnormality in the RF fetlock that was not visible on prior radiographs. The RF fetlock joint was injected with triamcinolone and hyaluronic acid (HA). If further treatment is required, biologics or polyacrylamide gels are recommended over corticosteroids. In cases where these treatments do not restore function, placing a screw distal to the subchondral defect may be considered.

Right Front shown above

Why This Case is Significant:

  • Radiographs initially suggested pathology in the coffin and pastern joints, which was confirmed by CT.

  • However, radiographs did not reveal any abnormalities in the fetlock, whereas CT clearly identified the lesion.

  • Adjusting image brightness and contrast further highlighted the lesion.

  • The cause of lameness, first detected via CT, was later confirmed through objective evaluation, demonstrating the value of advanced imaging in pinpointing subtle but clinically significant abnormalities.

This case earned 3rd place in Asto CT's Best Scans of the Year contest (Limb Category), recognizing the expertise of Dr. Kevin Keegan and his outstanding team at MU VHC Equine Hospital at Mizzou.

david ergun