Dr. Sallye Gregg

Staff Photo by Allison Kwesell Allison Touchstone, the department head of CT at River Vet Emergency Clinic, looks at 3 mm axial view slices of a dog's head in a CT scanner the clinic got in May.

Karen Armstrong's dog Speedy developed an unusual limp that doctors in May determined was probably a pulled muscle.

But when after six weeks it didn't get better, Ms. Armstrong drove her dog from her residence in Decatur, Tenn., to the Regional Institute for Veterinary Emergencies & Referrals, or River, on Amnicola Highway.

Technicians used the clinic's new CT scanner to find a cancerous mass on Speedy's spine.

"If it had not have been for that CT scan, I would have lost Speedy," Ms. Armstrong said. "It literally saved her life that there was something like that to detect it."

CT stands for computed tomography, which is a type of imaging that produces 3-D images from X-rays. The scanner itself is a doughnut-shaped X-ray machine with a table that slides in and out.

The machines are primarily used for people and typically cost several hundred thousand dollars, said Dr. Sallye Gregg, director of the hospital. The clinic got the scanner in early May and is leasing it from a company called Veterinary Imaging Partners based in Nashville.

"(The CT scanner) is fabulous. You begin to see things you can't see in regular radiographs," Dr. Gregg said. "We're diagnosing types of cancer that vets here can take care of."

Each scan costs about $775, most of which covers the cost of leasing the unit and anesthesia for the pet. The scanner works by providing many views of a pet's body through a series of "slices", said Allison Touchstone, who operates the scanner at River. After the scan is taken, the images appear on a computer screen and are immediately sent to a veterinary radiologist who reads them.

Since the machine arrived, Ms. Touchstone has performed scans of animals' sinuses, brains and spines.

"It is a lot better than looking at an X-ray," she said. "Instead of seeing the outline of an organ, you see the whole organ."

River is one of just a few veterinary clinics in the state to have such advanced technology, said Sandra Harbison, spokeswoman for the College of Veterinary Medicine at the University of Tennessee in Knoxville. It is unique for veterinarians to have this type of equipment for use on pets, but it is a growing trend, she said.

"People get this health care for themselves, so they expect to get it for their pets," Ms. Harbison said.

The CT scanner is not the only high-tech piece of equipment at River. The 24-hour hospital, a specialty referral clinic by day and an emergency clinic at night, also has one of the state's only hyperbaric chambers small enough for pets.

The chamber uses high-pressure oxygen to treat animals with a variety of ailments, including snake bites. The clinic uses an ultrasound machine to look at the hearts of dogs and cats to make sure they are beating as they should.

The clinic also uses a digital X-ray machine that puts images instantly on a computer monitor. Doctors can then manipulate the images to zoom in on a particular area or lighten or darken the image so one part can be seen better.

Once Speedy's tumor was found and diagnosed as a nerve-sheath tumor, a River surgeon removed it.

"She still has some pain," Ms. Armstrong said. "If we had not caught this tumor, she would have been paralyzed in her front legs."