Treating a Cooper’s Hawk with an Enlarged Spleen

Jul 29, 2015 / Student Blogs

Recently, a Cooper’s hawk (pictured above, being appropriately restrained for treatment) was brought to the Wildlife Medical Clinic by someone who found her on the ground, unable to fly. On observation, the bird was quiet and not very reactive. Now that may mean little or nothing to the inexperienced observer, but those familiar with this species can attest to the literal bouncing-off-the-wall insanity of a healthy Cooper’s hawk, so her behavior was actually quite concerning. A full physical exam, radiographs (x-rays), and blood work were all performed, and what we found suggested a significant infection. The bird had an enlarged spleen (the spleen filters circulating blood and produces new red and white blood cells) and an increased number of white blood cells (white blood cells help fight infection and are important for inflammation, among other things). The list of possible causes, or etiologies, of an enlarged spleen and increased white cell count is very long. So rather than stop there and try to guess the cause of infection (which we sometimes have to do, though these guesses are very educated and come with a great deal of experience), we took advantage of an opportunity to perform an endoscopy (endo—from within, scope—to look at).

hawkxrayAn endoscopy is performed with the animal under anesthesia, and the endoscope—a very fancy, long, thin instrument with a camera and light on the end—is advanced through a small incision in the bird’s abdomen and used to view the internal organs. What we saw confirmed the enlarged spleen and noted some changes in the liver, so tiny biopsies were taken and submitted for testing. The whole procedure took about 40 minutes, the bird was none the worse for wear, and we are (hopefully!) on our way to finding a cure for this girl. In the meantime, the hawk has been started on an antibiotic appropriate for several of the diseases she may have, and once we have the test results, we can tailor her treatment as needed to give this animal her best shot at a happy ending.

If you find a wild animal in need of help, the National Wildlife Rehabilitators Association is a wonderful resource for finding information and people who can help. The folks who make up this organization are brilliant and have loads of experience. Check them out here: And specifically, if you look at the left side of the screen, you’ll find a section titled “Help! I’ve Found an Animal.” Whether you’ve found an animal and need help, or found an animal and don’t need help, or haven’t found an animal at all, it’s worth checking out.

Photo at right: On a radiograph of the hawk, the large spleen is outlined in yellow. In most healthy birds, the spleen is either much smaller or not visible at all on radiographs.

Nicki Rosenhagen, DVM