As I mentioned in my last entry, we receive many young herons and egrets at SFBOWCEC during the summer. Over the last couple of weeks, we have been taking in several every day. Most are healthy, just birds that have fallen or been pushed out of the nest that need to be fed and kept warm. However, there are a few that come to us with significant medical problems, like this green heron.
This young bird came to the center over the past weekend. When I was able to first examine him/her yesterday, unfortunately, a fracture of the left femur was found. Here are his first set of radiographs (x-rays):
Managing fractures in young, growing birds presents some unique challanges. First, their bones are not completely mineralized and are susceptible to more fractures. Second, in many cases, the best repair of a fracture is acheived with surgery and implants (“pinning”). Because the bones of young birds are still “soft”, metal pins or other implants can move and cause the fixation to fail. Third, because the birds are still growing, the surgeon has to be very careful to avoid damaging the specific areas of the bones from where the growth occurs (growth plates). If these are damaged, normal growth of the bone could be impaired.
This green heron has a simple, long oblique fracture of the femur. In addition to the previously mentioned complications, the femur is especially difficult to deal with because splinting is very difficult given the anatomy of the bird leg. Also, the muscles overlying the femur are very strong and once the integrity of the bone is lost, which is working to keep the muscles elongated, the muscles contract causing the pieces of the fracture to overlap. The contraction of the thigh muscles in this bird had caused approximately 40% reduction in the length of the bone. Because green herons are perching birds that need to move slowly and stealthily to hunt successfully, legs of significantly differing lengths could severly impair the bird’s ability to thrive in the wild.
Weighing, the pros and cons, we decided to go ahead and attempt surgical correction of the fracture. A single pin was placed through the length of the bone and a second was placed perpendicular the first. The two pins are connected by a rigid bar that sort of acts like an external bone to offer support to the leg while the fracture is healing.
The surgery went well. The bird was a trooper under anesthesia and had an uneventful recovery. He/she is receiving antibiotics to help prevent infection and medication to manage pain. This morning, the bird was eating and using the leg, although still limping quite a bit.
So, things are looking OK so far, but we are very early in the process and many of the aforementioned complications could still occur. Keep your fingers crossed for him and watch for the update.
Shannon, OWCN Clinical Veterinarian