Veterinary Diagnostic Imaging Technologies - A Pet Parent's Guide

Diagnostic Imaging for Pets

Since our beloved pets can't tell us where they hurt or when they feel sick, diagnostic imaging can often play an essential role in pinpointing the exact cause of health concerns and injuries in dogs, cats and other animals.

There are a number of different technologies used to produce images and each technology has its pros and cons. Below we look at some of the different diagnostic imaging technologies used in veterinary care, and when your vet may recommend a particular test for your pet.

Dog & Cat X-Rays

Radiography - more commonly called X-rays - is one of the most helpful, and frequently used tools in veterinary healthcare. X-rays can help your vet to get a view of your pet's bones, tissues, and internal organs so that they can diagnose problems such as broken bones, bladder stones, swallowed foreign objects, and more. X-ray images can help vets to spot some tumors, pregnancy, and enlarged organs which may lead to a diagnosis such as heart disease or cancer.

X-rays will not provide a detailed view of your pet's organs, tissues, or ligaments using X-ray technology. In these cases, other diagnostic imaging such as MRI and ultrasound is more beneficial.

X-rays are painless, non-invasive, and considered very safe for dogs and cats. X-rays, particularly digital X-rays, use only very low doses of radiation. Because the level of radiation exposure required to perform radiography is very low, even X-rays of pregnant dogs are safe. Sedation is sometimes required in order to get a clear image of your body. If your dog or cat is calm, not in too much pain, and able to lay in a comfortable position while the X-ray is being taken, sedation will not be necessary. However, if your pet is unsettled, anxious, or in pain, sedation may be necessary.

Ultrasound Imaging for Pets

Pets frequently get into things they shouldn’t or develop health issues such as cysts or tumors that require treatment. Ultrasounds are a form of imaging technology that transmits sound waves into your pet’s body to produce a 'picture' of a specific body part. Veterinary ultrasounds are non-invasive and can be used to diagnose or evaluate problems with your pet's internal organs or check on your pet's pregnancy.

Your vet may turn to ultrasound imaging to get a clear picture of the condition of your pet’s organs in order to identify blockages, spot tumors or detect other problems.

Ultrasounds on different parts of your pet's body require different preparations. Speak to your vet to find out how to prepare your pet for their ultrasound. You may be required to withhold food and water for between 8 and 12 hours, particularly for abdominal ultrasounds. We can best examine the urinary bladder when it is full of urine. This is why your cat or dog should not urinate for about 3 to 6 hours before the ultrasound, if possible.

The area to be examined will likely be shaved so clear images can be produced. While most pets will remain still and cooperative during the ultrasound, some will need to be sedated.

Specialized Forms of Diagnostic Imaging for Pets

In some cases, your pet may be referred to a specialist clinic for other more advanced forms of diagnostic imaging such as CT scans, PET scans or MRIs. 

PET/CT Scan for Pets

Computed Tomography - CT Scans for Dogs & Cats

The high-resolution images produced by the CT machine help your veterinary team to evaluate your pet's anatomy in great detail - a level of detail that would be impossible to achieve with standard X-rays. 

CT scanners provide your vet with an outstanding image of your dog or cat's bony and soft tissue structures. CT technology is most commonly used to generate images of the spine, nasal cavity, inner ear, bones/joints, and the chest/lungs. We can also use the CT machine to assess lymph nodes, the thyroid gland, abdominal organs, the skull/brain, and vascular structures.

Positron Emission Tomography - PET Scans for Dogs & Cats

A CT scan combined with the use of a contrast agent given to your pet intravenously (IV), allows vets to see increased areas of blood flow in the animal's body. PET scans aid in the detection of cancer and areas of inflammation. In humans, PET scans are used to give doctors a detailed view of how the patient's tissues and organs are working. PET scans are most commonly used to detect and monitor cancer.

CT & PET Scan Process

CT and PET require that the animal stay completely still. For this reason, your vet will perform these diagnostic imaging tests while your pet is under general anesthesia. Your pet's vital signs are closely monitored while under anesthesia throughout the entire CT/PET process. In most cases, a CT/PET scan only takes a short time. Once the scan is complete the images will typically be interpreted by a specialist and a detailed report with findings and diagnostic recommendations will be sent to the vet handling your pet's treatment.

MRI - Veterinary Magnetic Resonance Imaging for Dogs & Cats

Magnetic Resonance Imaging (MRI) has been readily available to help diagnose human health concerns since the early 1980s, but it is only recently that veterinary MRIs have become more widely used.

MRI scans can provide your vet with high-resolution, detailed images of your pet's soft tissues including the brain, spinal cord, ligaments, tendons, and abdominal organs. For many types of soft tissue injuries or diseases, the use of veterinary MRIs can provide a more detailed image of your pet's body than other diagnostic imaging tools such as X-Rays or CT Scans.

If your pet is exhibiting symptoms such as limping, lameness, seizures, joint pain, neck pain, back pain, or paralysis, an MRI might be recommended to help diagnose the cause of your pet's symptoms. 

Dog and cat MRIs take between 45 minutes to an hour to perform. For an MRI to be successful the patient needs to remain absolutely still. In order to ensure that your pet's MRI is successful, a general anesthetic will be administered to your dog or cat prior to their scan MRI scan. Vets typically recommend blood tests and X-rays be done before the MRI to help ensure that your pet is strong enough to be put under general anesthetic.

Note: The advice provided in this post is intended for informational purposes and does not constitute medical advice regarding pets. For an accurate diagnosis of your pet's condition, please make an appointment with your vet.