History: For 10 years, Pal was the Pony Club mount for a young rider. Pal excelled at cross country events, and even took his rider to her B rating. During this time, he maintained excellent health, and never had any lameness issues. For the past 2 years, however, Pal has mostly been a pasture potato as his partner has gone away to college. He does give the neighbor children a jumping lesson once a week and goes on the occasional trail ride. Recently, both neighbors got to ride Pal in a lesson on a local cross country course. The next morning, Pal was acutely lame, and his left front leg was hot and swollen.
Veterinary Examination: Pal was mildly overweight. Otherwise, his physical examination was unremarkable except for his left front leg. The left front leg had an obvious area of swelling midway down the back of the cannon. The swelling was warm and painful to palpation. Pal was considered to be Grade 3 out of 5 lame, meaning he appeared sound at the walk, but was obviously lame when trotted in a straight line. Applying pressure to the swollen area increased Pal’s lameness dramatically.
Ultrasonography: Due to the presence of obvious swelling in the region of the flexor tendons, ultrasound was used for further investigation. A lesion was identified in the superficial digital flexor tendon (SDFT).
The image is a transverse view of the flexor tendons. The SDFT is the bright circular area at the top of the screen, and the lesion is the distinct black circle within the SDFT. The lesion is black due to tendon fiber disruption and the presence of blood or serum.
Diagnosis: Superficial Digital Tendonitis of the Left Forelimb
Discussion: Tendonitis, or a tendon “bow,” is inflammation of the tendon due to strain or disruption of the fibers. It is caused by excessive loading or overstretching of the tendon. There are several factors which predisposed Pal to an injury of this nature:
-Inadequate conditioning
-Obesity
-Uneven footing
-Muscle Fatigue
Treatment and Physical Therapy: For the 1st 48 hours, Pal was confined to a stall. He received 1g of Bute twice per day. The leg was cold hosed for 10-15 minutes three times daily and kept in a bandage with a mixture of DMSO and poultice. Starting on the 3rd day, Pal was handwalked for 10 minutes in an indoor arena with good footing. At this time, his Bute was decreased to 1g once per day. Hydrotherapy and bandaging were continued for two weeks. Over the next month, the length of time Pal spent handwalking was increased gradually, until he was walking for about 30 minutes per day.
Pal spent the 2nd month walking in the arena with a rider on his back until he had worked up to one hour per day. At the end of this time, a follow-up ultrasound was performed. Pal’s tendon healing was progressing well, so some jogging was added into his walking regimen. The amount of time spent jogging was increased gradually over the next several months. Five months after his injury, due to another good ultrasound, Pal was permitted to start adding cantering segments and integrating trot poles. He continued to heal well, and now, 8 months later, he has begun jumping small cross rails. Prognosis for full recovery is good.
