When Is A "Wind Puff" Abnormal?

Figure 1

 The "wind puff" noted in the right hind leg is not necessarily an immediate cause for alarm (Figure 1) . However, when you compare it to the left hind leg, there is a significant difference in the size of the wind puff between legs (Figure 2). This is a reason for concern!

A "wind puff" refers to the accumulation of synovial fluid with the distal flexor tendon sheath of the lower leg. All 4 limbs have a distal flexor tendon sheath and they extend from just above the fetlock down to the coffin bone area. Most people notice the swelling once it is above the fetlock joint however there is often significant fluid within the pastern area that goes unnoticed. For many horses that are in regular work a mild amount of fluid accumulation within the flexor tendon sheath is normal and should be symmetrical. When there is more fluid in one leg or a sudden increase in fluid then there is reason to be concerned.

Figure 2

Within the flexor tendon sheath there are a various tendons and ligaments. Any inflammation within these tendons and ligaments may result in a sudden increase in fluid within the sheath and eventually a reduction in performance. To thoroughly assess these soft tissues, an ultrasound exam should be performed and the soft tissue structures above AND below the fetlock should be evaluated. The image below is that of a abnormal deep digital flexor tendon. The area of concern is at the level of the fetlock joint and within the flexor tendon sheath.  The tendinitis has been chronic and there is evidence of tendon mineralization!. This horse was lame on presentation and there was significant fluid within the distal flexor tendon sheath.

Figure 3