Why is my dog's shoulder swollen and fluid-filled after an old injury?
Hello. I am sorry about your concerns about Chewy. It is possible that this is just a significant bruise & possible hematoma under the skin ( & probably in the muscle ) that is just taking a long time to resolve. A simple seroma should have resolved by now, but if there was a large blood clot that formed from the trauma, that may take a bit longer to resolve. The other, but less likely possibility is that the joint capsule at the scapulohumeral junction ( where the upper leg bone connects to the shoulder ) has torn. This can result in the leakage of joint fluid into the surrounding tissues. This can be repaired surgically if necessary. Your veterinarian will probably recommend an x-ray & try to sample the fluid to see if it is blood tinged ( a seroma ), bloody ( a hematoma ), or clear & stringy ( joint fluid ). None of these is life-threatening, but if this is joint fluid, Chewy could wind up with some arthritis in the shoulder. So do not worry too much until you have a chance to have things looked at. Thanks for using Petco Pet Education Center, formerly Petcoach.
Updated on September 23rd, 2025