X-ray and ultrasound

Veterinary medicine has made many advances in the last 10-20 years, and the vast majority of local veterinary practices will now be able to perform x-rays, and many will also be able to offer ultrasound examinations. These can be extremely useful in aiding a diagnosis for many potential disease processes.

An x-ray of a guinea pig with gastric dilatation
©Sarah Pellett

Your veterinarian can get a lot of information about what might be wrong with your guinea pig from talking to you and examining your guinea pig. Sometimes your veterinarian may need to take a blood, urine or feces samples to test for diseases or to monitor long term conditions. X-rays and ultrasounds allow your veterinarian to look at the organs/structures inside your guinea pigs body without having to perform an operation.

X-rays are like light beams, except they can travel through the body. For an x-ray your guinea pig will lie under the x-ray machine which sends a beam of x-rays through your guinea pig’s body onto a photographic plate. When the film is developed your veterinarian will have a two-dimensional picture of the inside of your guinea pig. This is called a radiograph. X-rays are black and white, and shades of grey, and different structures show up as different colors, ie bone is white, and fluid is black.

Veterinary ultrasound machines are just like the ones used by human doctors to scan babies in the womb. As its name suggests ultrasound is a form of sound. Just as sound waves can pass through solid objects (like doors and walls when your neighbor has a party!), ultrasound can pass through the skin into your guinea pig’s body. The sound waves are directed through the area your veterinarian wants to look at and some of them are reflected back like an echo. These echoes are detected by a special computer which uses them to produce a map of the inside of your guinea pig which your veterinarian views on a screen.

No, it is not possible to feel x-rays or ultrasound. For ultrasound examinations fur will need to be shaved over the area where your veterinarian is taking the picture. The ultrasound machine must be in contact with skin to let the sound waves get into the body. The hair should grow back quickly after the examination.

Taking an x-ray is a bit like taking a photograph of the inside of your guinea pig. For x-ray examinations it is important that your guinea pig lies still as the exposure is made or the final picture will be blurred. Veterinary nurses and veterinarians take many x-rays every day and for health and safety reasons are not allowed to manually restrain any of their patients or they would also be exposed to the x-rays, which can be dangerous over a long period of time. For this reason, unless the guinea pig is very poorly and unlikely to move when the x-ray is taken, a sedation or general anesthetic is likely to be required.

Ultrasound examinations can take up to an hour to perform. Although your pet can be held by a veterinary nurse while the veterinarian performs the examination, some guinea pigs do not like to be restrained and may have to be sedated.

X-rays, when used to produce pictures of your guinea pig will not cause side effects. Exposure to high doses, or over long periods of time, can be dangerous and this is why your veterinarian can’t hold your guinea pig for the procedure. There is no evidence that ultrasound examinations carry any risk at all.

The risk associated with the tests is that of upsetting a sick guinea pig or one with breathing difficulties by struggling with it, or the risk of the anesthetic or sedation in an ill guinea pig. Your veterinarian will discuss these risks with you and if you are in any doubt about the risk please ask your veterinarian to explain why they need to do the tests. In almost all cases the risk of not finding out what is wrong with your guinea pig, and therefore not being able to treat it, is far worse than the risk of the anesthetic.

X-rays are used to look for fractures to the bones, osteoarthritis, bladder stones and sludge, foreign bodies in the digestive system, dental disease and many more problems.

Ultrasound examinations are useful to determine pregnancy or problems when giving birth, bladder stones and sludge, tumors, heart, liver and kidney problems, and many more diseases.

Although your veterinarian will be able to see the pictures from these examinations, on the same day that they are taken, they may want to send them to a specialist for a second opinion before giving you a final diagnosis. Some veterinarians specialize only in reading x-rays and ultrasounds and may be less likely to miss information on the pictures. Some veterinary practices now have a specialist in the practice or one who visits the practice regularly to perform these examinations.

Your veterinarian will be happy to explain to you why they need to do tests on your guinea pig. If you do not understand the reasons, please ask someone to explain the tests to you. If you are interested, your veterinarian will probably be able to show you the pictures of your guinea pig after the examination and explain what they can see.