Success Story: A Close Encounter for Rooster Rascal

Written by: Krista Steffenhagen

Topics Addressed:

• Non-weight-bearing lameness
• Veterinary Medicine

Summary:

It all started on Friday January 14, 2005 when Rooster Rascal’s owners noticed that he was very lame on his right front leg. To their alarm, he was unwilling to do more than touch his toe to the ground. They thought that he had fallen on the ice and injured his shoulder. By Monday, he had not improved and it was time to take Rooster Rascal to the specialists at the Large Animal Hospital at the University of Minnesota Veterinary Medical Center for evaluation.

Dr. Mauro Verna from the Large Animal Surgery Service examined Rooster Rascal when he arrived. Dr. Verna performed a general physical examination to determine if Rooster Rascal had any other problems that might contribute to his lameness or might prevent a thorough lameness examination. Aside from a mildly elevated heart rate that was consistent with pain from his lameness, Rooster Rascal was in good general condition and Dr. Verna moved on to evaluate the lameness.

Based on his unwillingness or inability to bear weight on his right front leg, Rooster Rascal’s lameness was scored as 5 on a 5 point scale used to grade the severity of lameness. This scoring system helps veterinarians evaluate the response of a lameness to treatment and also can help identify possible causes. A “non-weight-bearing” (5/5) lameness indicates severe pain or instability, and is usually caused by one of three possible causes including a fracture, a sole abscess, or infection of a joint, bursa or tendon sheath.

Dr. Verna examined Roosters entire leg and did not find any area of swelling or pain on palpation or manipulation. However, Rooster Rascal’s hoof was warm to the touch. He cleaned out the sole but did not see a puncture or obvious wound. Nonetheless, he applied a hoof tester to the sole and frog to identify any areas of tenderness. The only area that caused Rooster Rascal to flinch was across the bulbs of the heel.

A nail in this location was cause for concern. Nails that penetrate near the frog can damage several critical structures. If the nail enters the bursa over the navicular bone or enters the coffin joint, it can create an infection in the bursa (bursitis) or the joint (arthritis) that would be very difficult to treat successfully.

To determine the extent of damage to Rooster Rascal’s hoof, Dr. Verna placed a sterile needle above the heel bulbs and directed it into the navicular bursa to perform a study called bursography. A sterile dye was injected into the navicular bursa and more X-rays were taken. As Dr. Verna had feared, the X-rays showed die leaking from the bursa along the nail tract, indicating it had punctured the navicular bursa. Fortunately for Rooster Rascal, there was no dye in the coffin joint between the pastern and coffin bones. To confirm that the coffin joint was not affected, a sample of fluid was taken from the coffin joint and tested for cells associated with infection. The nail had traveled through the frog, the digital cushion, the deep flexor tendon and the navicular bursa.

With the diagnosis clear, it was time to deal with the nail and the damage it had caused. Different treatment options were discussed

with Rooster Rascal’s owners and they decided to take the most aggressive approach possible in order to give Rooster Rascal the best chance for a full recovery.

The surgical team set up for arthroscopic surgery and the anesthesiologists administered a general anesthetic to Rooster Rascal. The gelding was moved into the surgery suite fast asleep. After careful preparation of the hoof, a small camera was inserted into the navicular bursa to examine the extent of damage and guide treatment. The camera transmitted an image of Rooster Rascal’s navicular bone and bursa to a TV screen. The deep flexor tendon was torn and the cartilage covering the navicular bone was damaged. A surgical currette was fed through the hole created by the nail to smooth the cartilage and remove damaged tissues. The bursa was flushed with fluids to help remove debris. Antibiotics were then injected directly into the bursa.

Before Rooster Rascal was awakened from anesthesia, a drainage hole was created in his sole and then packed with gauze soaked in an iodine solution to prevent shavings and debris from entering the hole. Antibiotics were given intravenously and also perfused into the local tissues by a process called regional limb perfusion. Rooster Rascal was much more comfortable after his surgery!

Two days later, Blair Rains the farrier who works with the complicated cases seen at the veterinary clinic, placed a special type of shoe with a removable plate over the sole. The shoe completely protected the sole but allowed bandages to be changed every other day. Five days after the surgery a sample of fluid taken from the navicular bursa showed no sign of infection.

Rooster Rascal returned home 5 days after his surgery with only mild lameness. He stayed on antibiotics for 3 weeks and his owners changed the bandage on the bottom of the foot 2-3 times per week for the next month. For the first two weeks his exercise was limited to 5-10 minutes of hand walks in order to minimize inflammation in the foot and to let the hole in the frog begin to fill with healthy tissue. The amount of exercise was slowly increased to prevent the flexor tendon that glides along the navicular bone from forming an adhesion to the bone (band of scar tissue). Rooster Rascal could resume his usual exercise routine two months after the surgery.

Dr. Mauro Verna is a senior surgical resident at the UMN-VC.