Veterinarians at Chicago's Brookfield Zoo performed a CT scan on a 7½-year-old eastern black rhinoceros named Layla. The scan, which is believed to be the first of its kind performed on a rhino, was necessary in order to determine appropriate treatment for a known obstruction in the patient's nasal passageway.

"As far as we know, this is the first time anyone has done a CT scan on an adult rhino, so we are in uncharted waters," said Michael Adkesson, DVM, DACZM, vice president of clinical medicine for Chicago Zoological Society, which manages Brookfield Zoo.

Layla's keepers became concerned about her last December when they observed her drooling and struggling to breathe. Veterinarians at Brookfield Zoo diagnosed her with obstructive sinusitis and, as rhinos primarily breathe through their noses, nasal obstructions are an immediate cause for concern. On Jan. 29, Layla underwent surgery by specialists Anthony T. Blikslager, DVM, Ph.D, DACVS, and Mathew P. Gerard, BVSc, Ph.D, DACVS, from North Carolina State University College of Veterinary Medicine and they determined she had a bacterial infection in her nasal passageway.

In the two months following the procedure, the rhino received weekly intravenous antibiotic therapy in an attempt to curb the infection; however, Layla's veterinary team remained unable to identify its source and determined advanced imaging would be required in order to save her life.

At 2,300 pounds, Layla was too large to be moved inside the zoo's hospital where the facility's CT scanner is located, so staff opted to bring a portable scanner to her habitat. A team of 40 staff members, as well as technicians from NeuroLogica and Sound Technologies, who donated their services to set up and operate the CT machine, assisted in orchestrating the procedure, which required the use of a front-end loader and a custom-made platform.

The images obtained from the scan revealed abnormal tissue associated with the root of one of the rhino's upper molars and determined the growth from the tissue is the source of the Layla's nasal blockage.

As they develop a plan to remove the tissue, the patient's veterinary team credits the scan for allowing them the ability to save her life.

"The CT scan provided diagnostic results that we could not have otherwise obtained," said Dr. Adkesson. "This procedure is an example of our commitment to providing the animals in our care with the most advanced medical treatment available. More importantly, though, the CT scan on Layla has provided us an unparalleled look inside of her skull. The images we obtained will guide our future treatment plan."

"We have high hopes right now that we are going to be able to get this infection cleared up and pull her through this," Atkesson continued. "We now have the info we needed to target into a specific area and get that affected tissue removed and hopefully get this infection cleared up."