Diagnostic tests are important in veterinary medicine since our patients do not routinely tell us where they are having a medical problem. An important diagnostic modality we use to make an accurate diagnosis on a sick animal is radiography, more commonly known as x-rays.

This is a fun and educational page designed to educate you on the basics of radiology. There is a fun test at the end to see how much you learned.  If you got them all right maybe you should apply to veterinary school!

Learning how to accurately read a radiograph on the wide variety of species that we care for requires requires a large body of knowledge. It is an ongoing process for our veterinarians in order to develop this skill. We oftentimes utilize the expertise of a veterinary specialist in reading radiographs of animals in the more complicated cases.

Student looking at a radiograph on the screen

We start our students down the path of this lifetime commitment to learning this skill early in their careers when they join our student externship program

Dr. Wood pointing to a problem tooth on a digital dental xray

Our digital radiography has dramatically enhanced our ability to find problems, and is especially useful when we do dental work on pets

Before we get started, let’s get some basics out of the way.


Several different angles are used to assess radiographs. The two that are used the overwhelming majority of time are:

  • the lateral (side) view  where a pet is laying on its right or left side
  • the ventrodorsal (VD) view where the pet is laying on its back. There is also a DV view with a pet laying on its abdomen

X-ray lateral (side) view of a cat abdomen

In this lateral view of thi fat cat the “R” means it is laying on its right side

This is a VD view of a fat cat

The same fat cat in this VD view. The “R” marker shows the right side of the cat

Radiographic Densities

There are five radiographic densities:

Soft tissue– internal organs like the liver and kidneys that have a whitish color

Fat– the fat around the internal organs, also with a whitish color. Without this fat you would not be able to differentiate the different internal organs like the liver or kidneys, since they are soft tissue, and have the same radiographic density.

Air– this is black, and is what you see for the lungs in a chest radiograph

Bone– which is brighter than soft tissue or fat

Metal– Vivid, very bright, and hard to miss


Look at each x-ray closely (sometimes very closely) and see if you can figure out what is wrong. We have a couple of clues to help you make an interpretation:

  • Use symmetry when you can. Compare both sides, legs, or whatever else that might be useful.
  • Pull your face away from the screen and scan the whole x-ray before you jump into the details.
  • After you have scanned the whole radiograph look very closely for subtle changes.

First we will show a bunch of fun radiographs of the more unusual pets we see at our hospital. After that we will do some radiograph reading lessons, teaching you about the normal anatomy of dogs and cats. After that is a little test to see how you did. We will stick to abdominal radiographs for the test to make it easier. Good luck, and have fun!

Exotic Animal Radiographs

These first few rads are helpful to get your eyeballs warmed up for your test at the end.

Pregnant Guinea Pig X-ray showing fetuses

Pregnant Guinea Pig. How many piglets do you see?

Bladder stone in an iguana Bladder stone in an iguana

Iguana bladder stones. Click here to see the surgery to remove a bladder stone in an Iggie. 

Mummified fetuses in a rabbit

Female rabbit with mummified fetuses that are several months old

Eggs in a California Desert Tortoise (CDT)

California Desert Tortoise (CDT) with eggs. Click here to see what they look like inside of a different tortoise when we do surgery to remove bladder stones. 

Two bladder stones in a guinea pig

Two small and white bladder stones in a Guinea Pig

Normal X-ray of a hawk

Normal hawk from our Wildlife Care Program

Hawk With A Broken Wing

Hawk with a broken wing (technically a mid-shaft fracture of the humerus) from our Wildlife Care Program

Calcium sludge in a rabbit urinary bladder

Calcium sludge in the bladder of a rabbit. This is called hypercalciuria, and you can read our detailed page on it

Calcified kidneys and a microchip in a rabbit

Did you also see the microchip and the calcium in the kidney?

Chinchilla skull and teeth

Chinchilla incisor and molar teeth

Snake with eggs inside Snake with eggs

Rabbit with a fluid filled uterus

Rabbit with a fluid filled uterus. To see how we took care of this problem follow this link.

Pellets in a hawk wing

Do you see the two pellets in this hawk’s wing?

Fracture and pellets in a hawk wing

Did you also see the fracture circled in red at the tip of the wing? How should this be handled? You can see what we did in our Wildlife  Care Page

 With such variability on what is normal or abnormal, many radiographs of the non dog and cat (we call them exotics) pets that we care for at the Long Beach Animal Hospital require the assistance of a specialist. The lab we use for our blood panels has a division called Antech Imaging Services (AIS) that gives us a detailed and written interpretation of these radiographs within 24 hours on all species, including the exotics. They have a veterinarian that is board certified in zoo animals to help us in interpreting the more difficult cases in exotic species.

Veterinarian Reading A Radiograph While In a Hammock

The veterinarian that reads radiographs for AIS is Marie Rush. Marie is dedicated to her profession and the well-being on sick animals. Even when she is out of the country doing conservation work she is still able to provide a turnaround time of 2 hours on interpretation of radiographs that are sent to her, although  she has different set of office furniture while in Costa Rica.

Normal X-Rays of dogs and cats

Enough of these exotics and wildlife, let’s get to the dogs and cats. They are mammals like us, and are easier (we didn’t say easy, though) to interpret than the exotics.

Dog Xray with breathing tube

A lateral X-ray of a dog’s chest and cranial abdomen. The head is at the far left.

Dog Xray with breathing tube labeled

Same X-ray as above, with an arrow pointing to the breathing tube for anesthesia, and the arthritis in the spine, circled in red

Normal cat abdomen lateral view

This is a radiograph of the abdomen of a normal cat that is laying on its right side. The head is towards the left. Use the diagram below to identify the organs.

Normal cat lateral abdomen with internal organs labeled

The stomach has food in it, and the large intestine contains feces. All five radiographic densities are present in this abdominal radiograph. Do you see all of them? 

Radiograph with all 5 radiographic densities

Air- is in the lungs along with gas in the intestines

S.T. -soft tissue is the liver and kidney

Fat- this is abdominal fat, also known as falciform fat

Bone- lumbar vertebrae

Metal- the R marker to indicate this cat is laying on its right side is made of metal

Normal cat chest and abdominal radiograph with organs labeled

Here is another normal cat abdominal and chest radiograph, this time with an empty stomach

Arrow pointing to stainless steel sutures

Here is another one, this time with the spleen and metallic sutures from a spay. You can easily see the liver (L), stomach filled with food (S) kidneys (K) , the small intestines (SI), the large intestine (LI), the urinary bladder (Bl), and the Spleen (Sp). The arrow points to stainless steel sutures in the muscle layer from a spay operation.

Abnormal X-Rays

Now that you know how to read normal dog and cat rads let’s look at some abnormal ones.

This dog is having a difficult time urinating. Can you tell what is wrong?

Abnormal dog abdominal radiograph

Look towards the right side of this abdominal radiograph

Labeled abnormal dog abdominal radiograph

Does labeling the organs help in your diagnosis?

Answers to abnormal dog abdominal radiograph

The bladder is huge, because this dog is having a difficult time urinating. It is probably due to nerve dysfunction, since the spinal cord has changes called spondylosis. The circle points this out on one of the vertebrae

You can learn more about this problem, called spondylosis, from our arthritis page

This is a dog abdominal radiograph. Notice anything unusual?
Dog X-ray with stones in the urinary bladder

Again, look towards the right side

Dog X-ray with stones in the urinary bladder circled in red

You can see the circle around the numerous stones (called calculi) in the urinary bladder

Dog X-ray with stones in the urinary bladder, with stones in kidney and urethra circled in red

Did you also notice the stones in the kidney and pelvic urethra?

Our web page on bladder stones has lots of good information on how we diagnose, treat, and prevent recurrence, of this disease.

This cat is labeled for you. Anything fishy?

Cat chest X-ray

Look towards the left side of the radiograph this time

Cat chest X-ray with pellet in neck circled in red

Did you see the pellet in the neck? Look again at the radiograph above, it’s plain as day.

Now that you are an expert at reading radiographs give the following one a try. It is from a cat that is straining to urinate and has blood in its urine. The answer is below, along with a picture with arrows pointing to the abnormalities.

Cat with stones in urinary bladder

This cat has 2 stones in its urinary bladder (click here to learn more about them and see a surgery of how they are removed). The stones are radiopaque, which means they show up easily on the radiograph. Some bladder stones are radiolucent, and can only be seen by injecting dye or air into the urinary bladder.

Cat X-ray pointing to stones in urinary bladder and stainless steel sutures

The arrows point to the bladder stones, along with the faint metallic sutures from a spay

Pretty easy so far, huh? Don’t get too confident just yet, our next few are a little harder. Look over the next few abnormal radiographs and send us an e-mail with your answer. If you aren’t sure and just need some clues e-mail us also and we will help you. Good Luck!

Abnormal X-Rays

Now that you are experts at reading x-rays, you can put your newfound skills to work. Email us at vet@lbah.com for the answers.

  1. What do you think about this cat radiograph?

Abdominal X-ray of constipated cat

2. This radiograph is an abdomen view from a very sick dog. It is 13 years old and losing weight

Abdominal X-ray of cat with a liver tumor

3. This is from an elderly dog that is losing weight

Abdominal X-ray of dog with cancer

3. This dog is limping on its rear leg

Tibia X-ray of dog with bone cancer called osteosarcoma

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