Abstract

Over the past 20 yr, the use of computed tomography (CT) in veterinary medicine has become more widespread, representing advancement in the standard of care. Dedicated equipment in veterinary colleges and referral centers has led to substantial use in domestic animals, but use of CT in zoological medicine remains fairly limited, restricted primarily to challenging clinical cases, high-profile specimens, and clinical research. Although many zoos have established a relationship with a local CT facility, its use is invariably limited due to issues of convenient access, animal/staff safety, and logistics with animal transport. There is really no substitute for immediate in-house access to CT technology, but the associated costs are substantial. Modernization of a hospital room, equipment purchase, and utility (electrical and ventilation) upgrades all represent significant investments. Service contracts and replacement parts are considerable ongoing expenses, as well as the necessary investments in training and education for staff to become proficient with CT unit operation and image interpretation.

In 2009 the Chicago Zoological Society (CZS) made the financial commitment to provide in-house CT imaging and installed a GE Medical Systems HiSpeed Advantage CT scanner in the veterinary hospital, making it one of only three zoos in the world with CT technology on site. Immediate, unlimited access to the scanner has provided numerous enhancements in the level of veterinary care that can be provided at the zoo. Scans are completed quickly and efficiently, without the need for off-site transport, drastically decreasing anesthetic times and eliminating many logistic and safety-related challenges. New examination findings that indicate a need for CT can be addressed immediately, precluding the need for an additional anesthetic event, a particularly great benefit for patients with high anesthetic risks or that require complicated immobilizations.

The daily challenges of zoological medicine also provide many new prospects for CT use and the opportunity to incorporate CT imaging into many routine procedures. Routine use of CT can provide diagnostic benefits not available with other imaging modalities and may accelerate reaching a diagnosis in many cases. CT imaging with 3D reconstruction is a valuable tool for assessing skeletal morphology, organ position, and surgical approaches in species where detailed anatomic information is sparse. Routine CT use for dental evaluation is a valuable tool in species where adequate oral visualization is challenging (e.g., aardvarks, macropods, rodents). At CZS, CT scans are becoming standard practice in certain species during quarantine and preventative health examinations to evaluate potential concerns and provide a ‘baseline’ for future comparison. In certain species, whole body scans are performed during regular exams to begin establishing a database of normal CT anatomy. Interventional procedures (e.g., CT-assisted aspirates and biopsies) are also greatly facilitated by immediate on-site CT access. Such procedures can have significant diagnostic and therapeutic benefit and represent another emerging use in zoological medicine.

There is a clear benefit in having CT available for difficult clinical cases, but we are only beginning to recognize the advantages of routine use and the full spectrum of potential applications in zoological medicine. As costs continue to decrease and use becomes more widespread, CT will certainly become a standard in the practice of zoological medicine.

Acknowledgments

The Chicago Zoological Society graciously acknowledges Loyola University Medical Center for the donation of a CT scanner, the Aurelio Caccomo Family Foundation for their support of installation and renovation costs, and the staff at VIZUA™ for their assistance with image rendering. The author also thanks Drs. Tom Meehan, Jennifer Langan, and Carlos Sanchez.