X-Rays and Your Pet
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Pet Column for the week of March 25, 1996
Office of Public Engagement
2001 S. Lincoln Ave.
Urbana, Illinois 61802
Phone: 217/333-2907
By Linda March
Information Specialist
University of Illinois
College of Veterinary Medicine
X-rays--they are almost like magic. You can see into your pet's body with an X-ray.
According to Dr. Kerri Beck, veterinary radiology resident at the University of Illinois
College of Veterinary Medicine at Urbana, "X-rays are electromagnetic waves, much like
light, only not in the visible spectrum. X-rays can penetrate body tissues and many other
things to varying degrees."
During an X-ray procedure, electrons go through the patient and are absorbed to varying
degrees by the animal. Those that make it all the way through hit a film and provide an
image that is like a negative. The more electrons that go through the animal, the darker the
image on the film. The fewer electrons pass through, the lighter the image on the film.
When your veterinarian looks at a radiograph (X-ray), he or she looks for different
opacities (shades of dark and light). Air allows the most X-rays through the animal, resulting
in a dark image. Fat is the next opacity, creating a lighter image than air. Lighter still is fluid
or soft tissue, then bone. The lightest opacity is metal. It leaves a bright white image on the fi
The X-ray film is developed much like photographic film in a processor.
Dr. Beck notes, "Taking X-rays of an animal is different than for humans. You can ask a
human to hold still. Pets are sometimes not as cooperative."
When positioning a pet for an X-ray, the animal must usually be sedated to get it to lay still.
Proper positioning is especially important when one is taking OFA radiographs to see if a
dog has hip dysplasia. Your veterinarian must work quickly to obtain the necessary films,
because sedation is short-acting (about 30 minutes).
X-rays can help your veterinarian diagnose problems with your pet. If your veterinarian
feels a lump or mass in your pet's abdomen, an X-ray can help pinpoint what organ the
mass is in, be it the spleen or the stomach. Similarly, if X-rays reveal bunching and irregular
gas patterns in the small intestine, your veterinarian can deduce that your pet has eaten
string or holiday tinsel if you've also told him or her that the pet is vomiting and going off
feed.
"We've seen some strange things in stomachs," notes Dr. Beck, "Even scouring pads and a
plastic toy soldier."
Other conditions that can be observed with X-rays include gastric dilation volvulus (twisted
stomach), broken bones, cancer masses, heart problems, or even fungal diseases.
"X-rays are very low risk for your pet. They are more of a risk for the people who are
involved in taking the X-rays of your pet," says Dr. Beck.
There are immediate and long-term effects of X-rays. To protect X-ray personnel from side
effects such as mutations or birth defects, they must wear lead aprons and gloves when
making radiographs.
If the X-ray (radiograph) gave an indication of a problem, but wasn't a definite diagnosis,
your veterinarian may turn to ultrasound, another imaging device. Ultrasound allows the
veterinarian to see things that cannot be seen on X-rays.
"Ultrasound is like sonar. The high frequency sound waves are directed into the body and
bounce back off of the organs. A computer image that allows you to see inside the organ is
produced on the screen," states Dr. Beck.
Ultrasound can distinguish fluid from a soft tissue mass or nonradiopaque stone in an organ
such as the kidney. This can guide your veterinarian to a proper treatment for your pet.
If you have any questions about X-rays or ultrasound, ask your veterinarian.