make such adjustments, we collaborate with experts in other medical fields, including domestic and large animal veterinarians, physicians, medical technicians, and veterinary and human dentists. Adding to the challenge, most of our patients must be restrained, anesthetized, or trained for months before they will tolerate even simple technology-based procedures. A sick octopus in need of a set of X-rays, for example, requires three sets of hands and a barrel of water, with a water-soluble anesthetic available as backup.
Radiography, the production of images using X-rays, is a good example of the application of medical technology in zoological medicine. In both humans and animals, bones and other cartilaginous structures appear white, internal organs appear various shades of gray, and air-filled structures appear black. X-ray images readily show the patient's skeleton, including its teeth, and the outline of major structures such as the heart, lungs, intestinal tract, liver, kidneys, and bladder.
The size and density of the animal determines the type of cassette that holds the film and the power required to produce the image. Dental film, the kind we humans bite down on while sitting in a dentist's chair, works fine for whole-body images of tiny animals like hummingbirds, small fish, and frogs. We use standard-sized X-ray cassettes for small mammals like meerkats and monkeys, or for various body parts of larger animalsâthe thorax of a wolf, the abdomen of a tiger, the skull of a tapir, or the hoof of a zebra. Whether the exam is performed in a fully equipped veterinary hospital or in the field, the patient is almost always anesthetized or lightly restrained.
Interpreting the X-ray images poses another challenge. Experience and knowledge of comparative radiographic anatomy are crucial to accurate interpretation, and even then opinions may vary. The radiographic anatomy of a gorilla most resembles that of a human, but with quite a few differences, not the least of which is the size of the hands and skull relative to the body and the presence of air-filled sacs located beneath the neck and in each armpit. Birds have air sacs too, and some of their bones are full of air cavities. But there are many differences among these species as well. An X-ray of a parrot looks very different from that of a hawk.
With the arrival of digital photography and digital radiography, many zoo vets use e-mail to send radiographs to experts at other institutions for another opinion. As a whole, our profession has been quick to take advantage of the Internet. Not only do we use this tool for communication, it's often the first place we look for the latest medical technology.
Zoo vets show their low- and high-tech creativity in the next group of stories: horseshoes give a rhino relief, fiber-optic instruments help pandas, massive portable life-support systems transport whale sharks halfway around the world, orthopedic surgery helps a falcon, and frogs benefit from a new anesthetic method.
Lucy H. Spelman, DVM
The Rhino with Glue-On Shoes
by Lucy H. Spelman, DVM
T here had to be a better way to deal with this rhino's feet. Blood dripped from Mohan's foot pads as veterinarians and technicians worked furiously to carve away diseased tissue. These were not small feetâeach one measured about ten inches in diameter. A growing pile of soiled gauze and towels littered the floor. Next, bandages would go on. Then we'd roll the rhino over to work on the other side. The blood didn't worry us. Even if Mo lost a few pints during the trim, the 5,000-pound animal wouldn't know it.
In an odd sort of way, we were glad to see red. The blackened, unhealthy tissue wedged between his toes and into the cracks of his soles had outgrown its vascular supply. His back feet were the worst. We trimmed off the outside layers until we got down to healthy tissue, which bled profusely. I watched the foot-trimming team for a minute or so, long enough to gauge how much
Radiography, the production of images using X-rays, is a good example of the application of medical technology in zoological medicine. In both humans and animals, bones and other cartilaginous structures appear white, internal organs appear various shades of gray, and air-filled structures appear black. X-ray images readily show the patient's skeleton, including its teeth, and the outline of major structures such as the heart, lungs, intestinal tract, liver, kidneys, and bladder.
The size and density of the animal determines the type of cassette that holds the film and the power required to produce the image. Dental film, the kind we humans bite down on while sitting in a dentist's chair, works fine for whole-body images of tiny animals like hummingbirds, small fish, and frogs. We use standard-sized X-ray cassettes for small mammals like meerkats and monkeys, or for various body parts of larger animalsâthe thorax of a wolf, the abdomen of a tiger, the skull of a tapir, or the hoof of a zebra. Whether the exam is performed in a fully equipped veterinary hospital or in the field, the patient is almost always anesthetized or lightly restrained.
Interpreting the X-ray images poses another challenge. Experience and knowledge of comparative radiographic anatomy are crucial to accurate interpretation, and even then opinions may vary. The radiographic anatomy of a gorilla most resembles that of a human, but with quite a few differences, not the least of which is the size of the hands and skull relative to the body and the presence of air-filled sacs located beneath the neck and in each armpit. Birds have air sacs too, and some of their bones are full of air cavities. But there are many differences among these species as well. An X-ray of a parrot looks very different from that of a hawk.
With the arrival of digital photography and digital radiography, many zoo vets use e-mail to send radiographs to experts at other institutions for another opinion. As a whole, our profession has been quick to take advantage of the Internet. Not only do we use this tool for communication, it's often the first place we look for the latest medical technology.
Zoo vets show their low- and high-tech creativity in the next group of stories: horseshoes give a rhino relief, fiber-optic instruments help pandas, massive portable life-support systems transport whale sharks halfway around the world, orthopedic surgery helps a falcon, and frogs benefit from a new anesthetic method.
Lucy H. Spelman, DVM
The Rhino with Glue-On Shoes
by Lucy H. Spelman, DVM
T here had to be a better way to deal with this rhino's feet. Blood dripped from Mohan's foot pads as veterinarians and technicians worked furiously to carve away diseased tissue. These were not small feetâeach one measured about ten inches in diameter. A growing pile of soiled gauze and towels littered the floor. Next, bandages would go on. Then we'd roll the rhino over to work on the other side. The blood didn't worry us. Even if Mo lost a few pints during the trim, the 5,000-pound animal wouldn't know it.
In an odd sort of way, we were glad to see red. The blackened, unhealthy tissue wedged between his toes and into the cracks of his soles had outgrown its vascular supply. His back feet were the worst. We trimmed off the outside layers until we got down to healthy tissue, which bled profusely. I watched the foot-trimming team for a minute or so, long enough to gauge how much
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