What is veterinary special diagnostic imaging for dogs?

Animal Clinic of Billings veterinarian Christiane Youngstrom and veterinary assistant Jamie Gratwohl preparing a dog for an MRI at our Billings MRI facility

Veterinary diagnostic imaging refers to Ultrasound, Radiography (X-rays), MRI, Doppler Echocardiogram, and CT Scans. Veterinary diagnostic imaging enables us to detect illnesses and abnormalities in dogs that cannot otherwise be appreciated, and to do so in a non-invasive and non-painful manner. Ultimately, the goal of any specialized form of diagnostic imaging is to definitively detect an abnormality and determine its extent in the body without resorting to more invasive interventions, such as surgery.

Some imaging modalities, such as MRI and CT scans, require sedation or even anesthesia because a dog must be kept completely still to allow for highly detailed images to be acquired. Our veterinarians are then able to evaluate these images to establish a diagnosis and determine the best course of treatment.

As part of our diagnostic services, The Animal Clinic of Billings and Animal Surgery Clinic is equipped with digital X-ray and digital X-ray monitoring for both general and dental X-rays. Our doctors also perform ultrasound examinations in in-house, and routinely coordinate MRI and CT scans. Our facility is also equipped with a cutting edge in-house diagnostic laboratory to provide real-time lab results so that we may rapidly evaluate a patient’s status and implement the most appropriate treatments.

When is ultrasound, X-ray, and MRI needed on dogs?

If your veterinarian suspects your dog may have an internal abnormality after performing a physical examination, diagnostic imaging is typically the next step to acquire more information. It’s important to understand that for some conditions, multiple types of diagnostic imaging procedures may be required to reach a definitive diagnosis.

X-rays are typically the first type of diagnostic imaging performed. If a broken bone (fracture) is suspected, X-Rays are taken both of the injured limb as well as the opposite limb for comparison. Your veterinarian will use the X-Rays to establish the best treatment plan.

If surgery is necessary, the X-rays are used to determine the best strategy for internal stabilization, including implant type(s) and the size of plates, pins, or screws required. If X-rays are inconclusive or the problem resides in the soft tissue of the dog, then ultrasound or an MRI may be required to get a more thorough look at the area in question.

Let’s say you bring your dog in because he or she is vomiting. One of our veterinarians will likely start by taking an X-ray to rule out the possibility of an intestinal obstruction due ingestion of a non-digestible foreign body. If the X-ray shows potential signs of intestinal obstruction but is not definitive, then either an ultrasound or a contrast X-ray study may be necessary to confirm the diagnosis before proceeding to surgery.

In a contrast GI X-ray study, the patient is given a solution containing barium to drink. Barium shows up bright white on x-rays, and through serial X-rays of the abdomen, the barium can be observed making its way through the stomach and intestines. If it stops abruptly at any point, this indicates the presence of a blockage.

X-Ray of a broken femur on a dogMulti-modal imaging allows for greater confidence in a diagnosis and treatment plan, which is particularly important when the treatment is invasive or involves risk. Different diagnostic imaging modalities provide different types of information about an abnormality that can all be integrated to generate the most complete picture of what is going on.

As another example, if your dog is not using his or her hind limb normally due to pain in their knee, possible causes include a torn cruciate ligament, torn meniscus, torn collateral ligaments, a luxating patella, patellar tendonitis, osteoarthritis, joint infection, immune-mediated joint disease, avulsion of the tibial tuberosity, and many others.

x-ray of broken leg on a dogX-rays of the dog’s knee will often show signs of soft tissue swelling or fluid buildup in or around a specific area but may not pinpoint precisely which structure is damaged. Therefore, in some cases more advanced imaging with an MRI or CT scan may be necessary to make a definitive diagnosis.

Because an MRI is much more expensive than X-rays, we will almost always start with X-rays and only resort to more expensive imaging modalities if there is uncertainty about the diagnosis. In most cases, our veterinarians are able to identify the problem from the initial X-rays and ultrasound enough to confidently determine the best treatment protocol for your dog.

How many types of diagnostic imaging procedures are there?

Animal Surgery Clinic of Billings patient with two broken femurs, repaired by Dr. Brown. We’re happy to report the dog is getting along great now.

There are six types of veterinary diagnostic imaging procedures our veterinarians may utilize to assist in the diagnosis of your dog’s condition. They include:

  • X-ray
  • MRI
  • Ultrasound
  • CT Scan
  • Doppler Echocardiogram
  • Endoscopy

X-rays on dogs

Animal Clinic of Billings veterinarian and owner Dr. Brown examining an Xray of a dog’s organs

X-rays, also known as radiographs, have been used to diagnose medical problems in dogs, humans, and many other animals for over 100 years. X-rays are by far the most commonly used form of diagnostic imaging in veterinary medicine because they are more affordable than other types of diagnostic imaging and they are very useful for accurately diagnosing a wide variety of both bone and soft tissue abnormalities throughout the body.

Today, digital radiography has become the gold standard for how radiographic images are obtained. Digital X-rays are extremely helpful for diagnosing and monitoring a wide variety of conditions. At the Animal Clinic of Billings and Animal Surgery Clinic, we are equipped with both dental and general digital radiographic imaging.

Different from traditional X-Rays, modern digital X-rays expose the patient to significantly less radiation and eliminate the use of harsh processing chemicals. Additionally, the digital images produced are ready to view within seconds, have overall better picture quality, can be easily manipulated and magnified for superior evaluation, and can be shared instantly via email.

X-rays are used to determine the presence of many internal conditions that cannot be otherwise detected such as:

  • Pulmonary diseases such as pneumonia and asthma
  • Airway diseases such as bronchitis and collapsing trachea
  • Heart disease and congestive heart failure
  • Broken bones (fractures)
  • Gastrointestinal foreign bodies
  • Internal masses/tumors
  • Joint diseases such as arthritis
  • Kidney and bladder stones
  • Jaw bone loss due to periodontal disease and tooth root abscesses
    and many more

What happens when a dog has an X-Ray?

Broken and repaired front leg, or Radius and Ulna on a dog patient at the Animal Surgery Clinic of Billings by Dr. Brown. The dog made a full recovery and is getting along great now

First, the dog is positioned on the x-ray table precisely so that the area of concern is beneath the X-ray machine. The x-ray machine is adjusted to the most appropriate setting for the width of the body part being x-rayed, and an image is taken.

This is perfectly safe for your dog as the levels of radiation emitted from modern digital X-Ray equipment like the ones used in our hospital are too low to cause any adverse effects. Sometimes sedation may be required in order to properly position a patient who is painful or uncooperative.

Ultrasound on dogs

Animal Clinic of Billings veterinarian Dr. Bryna Felchle preparing for an ultrasound session with a dog

The second most commonly-used type of veterinary diagnostic imaging is ultrasound.

Ultrasound is a non-invasive, non-painful technique that produces a real-time image of your pet’s internal organs by emitting high-frequency sound waves through a sensor. Ultrasound helps to diagnosis abnormalities that don’t show up as well on X-rays, such as a mass hidden within an organ or the presence of thickened intestinal walls. Ultrasounds are typically not stressful for your dog and take anywhere from 15 to 30 minutes to perform.

veterinarian Dr. Massic and vet tech Mandy Smith using our ultrasound lab to look for foreign objects and potential illnesses in the abdomen of a dog at the Animal Clinic of Billings

Ultrasound is also used to collect diagnostic specimens, including fluid and tissue samples. Ultrasound biopsies are minimally invasive and have few complications compared to undergoing surgery for a biopsy. However, ultrasound biopsies provide only very small samples and sometimes do not yield a definitive diagnosis; therefore, in some cases, a surgical biopsy is necessary.

What happens to a dog during an ultrasound procedure?

During an ultrasound, your dog is carefully placed in a padded trough on a table. Your veterinarian then applies alcohol or ultrasound gel to the skin surface in the area of interest, and gently presses a small probe against the area. This probe emits digital sound waves to produce a diagnostic image of the underlying interior structures.

The veterinarian moves the probe manually until a clear image of the internal area being targeted is displayed on the screen. The images generated by these sound waves are viewed in real time on a computer screen, and can also be stored and saved in a computer to view later.

In modern scanning systems like the one the Animal Clinic of Billings and Animal Surgery Clinic, our veterinarians can integrate the information from an ultrasound to determine a definitive diagnosis for your dog and devise the most effective treatment protocol to achieve the best possible outcome.

cat MRI imagesCT Scans for dogs

A CT scan uses technology similar to that of conventional X-rays, but much more advanced, to generate a three-dimensional view of the body. CT scans are particularly useful for imaging bones, joints, and the chest. A dog must be sedated for a CT scan to ensure that they remain still for the duration of the scan. At the Animal Clinic of Billings, we routinely coordinate CT scans to diagnose a wide variety of injuries and illnesses.  

Veterinary MRI for dogs and cats in Billings MT

MRI machine and facility with which all Animal Clinic of Billings MRI’s are taken

The Animal Clinic of Billings and Animal Surgery Clinic is proud to provide state-of-the-art veterinary MRI services in Billings Montana for our canine and feline patients.

Because of the special nature of MRI scanning and the prohibitive cost of the equipment, the Animal Clinic of Billings and Animal Surgery Clinic has established a partnership with a locally owned and operated Billings-based MRI facility designed for human care. This allows us to provide dogs and cats with the most cutting edge MRI technology available.

What is an MRI for dogs?

MRI, short for Magnetic Resonance Imaging, uses a very powerful magnet – 40,000 times stronger than the earth’s magnetic field—to generate detailed images of the body. While it is very powerful, it does not emit any radiation, and is an extremely safe procedure.

How does a veterinarian perform an MRI of a dog?

During an MRI, the dog is positioned to lie flat on a table that moves into the center of a domed-shaped MRI machine. After removing any metal from the patient (such as a collar), the vet will safely anesthetize the dog and monitor them throughout the scan.

veterinarians checking dog x-raysBecause it does take longer than an X-ray or CT scan to acquire the necessary images, heavy sedation or anesthesia is required to ensure that a pet does not move, which would result in distorted and non-diagnostic images.

The MRI itself works by using a magnetic field and radio waves to create images. The procedure can show abnormalities, injuries, and diseases that may not be seen with any other method, with picture clarity and detail superior to other types of diagnostic scans.

An MRI often takes more than an hour to complete, so the dog is under anesthesia for a while, but rest assured that one of our veterinarians is always there to closely monitor the dog’s condition and ensure everything goes as smoothly as possible.

What can a veterinarian see from an MRI on a dog?

An MRI can show detailed differences in a dog’s tissue density, which can reveal tumors or other subtle abnormalities that might be difficult to see in ultrasound or CT scans. Sometimes, the patients are injected with a safe contrast material during an MRI to allow for even greater visual detail in differentiating between structures or features of interest within the dog’s body.

MRI is commonly used to diagnose numerous conditions, including:

  • Brain pathologies (trauma, tumors, malformations, strokes, and infections)
  • Vertebral abnormalities
  • Intervertebral disk disease (IVDD)
  • Spinal cord injuries and tumors
  • Bone, ligament, and tendon injuries and diseases
  • Joint diseases
  • Growths or infections in the sinuses
  • Vascular disease and blood clots
  • Tumors, infections, injuries, and other disease processes within internal organs

Is an MRI safe on dogs?

Unlike X-rays and CT scans, MRI scans don’t emit any radiation, so it’s actually considered to be safer than X-rays and CT scans. Additionally, the MRI procedure itself has no known negative side-effects on dogs or people. Regardless, we take every safety precaution to minimize the risk of complications to our MRI patients.

We check bloodwork prior to administering any sedation or anesthesia in order to detect any conditions that might increase the risk of anesthesia, such as kidney or liver dysfunction. During the scan, we closely monitor our patients to ensure that they are handling the medications well. You can rest assured that if an MRI is needed for your dog, he or she is completely safe and in good hands.

Doppler echocardiograms on dogs

Another specialized diagnostic tool is a Doppler echocardiogram. Echocardiograms produce very precise ultrasound images of the heart and cardiovascular system. An echocardiogram can show the contractions of the heart, the movement of it’s valves, and even the blood flowing through the arteries, all in real time.

If your dog has been diagnosed with a heart murmur or some other heart-related problem, our veterinarians and staff are here to help you through every step of achieving the best possible outcome for your canine companion. At the Animal Clinic of Billings and Animal Surgery Clinic, we coordinate echocardiograms in order to diagnose and monitor heart disease.

Endoscopy on dogs

An endoscope is a small camera mounted on a fiber optic cable that veterinarians use to visually examine the GI tract. Using this tool, a veterinarian can directly visualize the interior of the esophagus, stomach, and first segment of the small intestine, as well as the colon.

Biopsies can be collected to diagnose GI diseases, and in some cases foreign objects can be removed, enabling a patient to avoid needing surgery. In order to undergo an endoscopic procedure, a patient must be anesthetized. This is a very useful tool that in some cases allows for the diagnosis and treatment of a patient without surgery.

Let us help you keep your dog as happy and healthy as they can be.

If you’re concerned your dog might be injured or are looking for a veterinary hospital in Billings that offers MRI and CT scans for dogs and cats, please contact us to schedule an appointment with one of our veterinarians today!






providing our region’s companion animals and their families what they need and deserve since 1981

1414 10th St. West, Billings MT 59102