May Case of the Month: Shouldering the Damage
Stella was seen on a semi-urgent basis, after some swelling developed at the point of her left shoulder following a horse show. She had been kicked in that location about a month prior, but had not been seen by a vet as she had not been lame.
The swelling was an ovoid 4x5cm, soft and not painful on palpation. The mare was not lame in-hand, and reportedly not lame under saddle. On ultrasound, the muscle system that runs from the side of the horse’s neck all the way down to the point of their shoulder (brachiocephalicus), inserting on the point of shoulder, was partially torn. The part of the muscle group affected was the cleidobrachialis. A grade 2 insertional tear with an associated pocket of fluid (seroma) was present. The muscle had likely been damaged by the kick a month ago but had been inflamed by continued ridden work, creating a fluid pocket. The owner was quite surprised an injury was present as the mare was acting unphased by the injury. Proximal muscle injuries can be well compensated for until they are really painful or become more extensive.
Stella should recover with a targeted rest and rehabilitation program; recheck ultrasounds will monitor the muscle’s healing. Ultrasound is an important medium for investigating many abnormalities and developing a targeted treatment plan in these cases, especially with swellings or masses, even if lameness and pain aren’t initially present.
