Location: A lump or bump on the back or to the side of your horse’s
cannon-bone area may mean he’s experienced an injury to one of the flexor tendons.
What it is: When tendons are first injured, torn fibers can lead to bleeding and fluid accumulation within the tissues. This fluid can create a lump. If a tendon injury is old, scar tissue may have formed.
Look and feel: A fresh tendon injury will be firm, and usually sensitive to pressure if you squeeze it with your fingers. An old tendon injury may feel almost bony, and will not be sensitive to pressure.
Should you worry: If your horse has a new, sensitive bump over the tendon area, call your vet—especially if your horse is lame. An ultrasound can tell you if the tendon has been injured and if so, how badly. This is a scenario where knowing what your horse’s legs look like on a normal day is especially important.