Veterinary diagnostic tests for pets are an exceptional tool used by our Los Angeles veterinarians to help us pinpoint the cause, extent, or seriousness of your pet's illness or injury. Depending on your pet's condition, the type of pet diagnostic test used will vary. Below are a few of the tests that your vet may recommend to help diagnose or treat your dog or cat.

Why are diagnostic tests important for pets?

Diagnostic tests for pets are important because they help veterinarians accurately identify and treat various health conditions. These tests can provide valuable information about a pet's overall health, such as bloodwork to assess organ function or imaging to detect abnormalities in the body.

Additionally, diagnostic tests can help catch potential health issues early on, allowing for prompt intervention and better outcomes. For example, routine blood tests can detect conditions like diabetes or kidney disease before symptoms become severe, giving pet owners the opportunity to address these issues before they progress.

Below, we’ll discuss some of the most common types of diagnostic tests.

Radiography (X-Rays)

X-rays are an important diagnostic tool in animal laboratory testing. They allow veterinarians to identify issues such as broken bones, bladder stones, swallowed foreign objects, and more. They can also help detect tumors, pregnancy, and enlarged organs, which can lead to heart disease or cancer diagnosis.

Because X-rays do not provide a detailed view of a pet's organs, tissues, or ligaments, other diagnostic imaging techniques, such as MRI and ultrasound, are more useful.

X-rays are non-invasive, painless, and considered very safe for dogs and cats. They only use very low doses of radiation, and pregnant pets are not affected. Sedation is sometimes required to obtain a clear image of the body. But sedation may not be required if the dog or cat is calm, not in too much pain, and able to lie in a comfortable position.


Ultrasounds are a type of imaging technology used to diagnose or evaluate problems with a pet's internal organs, as well as to check on their pregnancy. They are non-invasive and can be used to detect and treat medical conditions like cysts and tumors.

Different preparations are required for ultrasounds on different parts of your pet's body. Consult your veterinarian to learn how to prepare your pet for an ultrasound. For abdominal ultrasounds, you may be asked to refrain from eating or drinking for 8 to 12 hours. We can examine the urinary bladder more thoroughly when it is full of urine. This is why, if, at all possible, your cat or dog should refrain from urinating for 3 to 6 hours prior to the ultrasound.

The area to be examined will most likely be shaved to produce clear images. While the majority of pets will remain still and cooperative during the ultrasound, some will require sedation.

PET/CT Scans

CT and PET scans require your pet to be completely still. Thus, your veterinarian will likely administer general anesthesia. Vital signs are monitored, and the scan is quick. A specialist interprets the images, and a detailed report is sent to the veterinarian who is treating the pet.

Computed Tomography - CT Scans

CT scans produce a high-resolution image of the bony and soft tissue structures of a dog or cat, including the spine, nasal cavity, inner ear, bones/joints, and chest/lungs. They can also be used to evaluate the lymph nodes, thyroid gland, abdominal organs, skull/brain, and vascular structures.

Positron Emission Tomography - PET Scans

This is a CT scan combined with the administration of a contrast agent intravenously (IV) to your pet. This allows veterinarians to see increased areas of blood flow in the animal's body. PET scans help detect cancer and areas of inflammation.


Before any visible symptoms appear, blood tests can detect the earliest signs of illness. They can help with disease or illness detection, identification, diagnosis, and treatment. Blood tests are also required during routine exams for healthy pets to obtain normal baseline values. Diagnostic blood tests can help your veterinarian determine the cause of your dog's symptoms.

A complete blood count (CBC) and a complete blood chemistry panel, which includes electrolytes and urinalysis, are two commonly used tests for diagnosing anemia, inflammation, infection, immune system response, and blood clotting ability. The chemistry panel and electrolytes provide information to your veterinarian about your pet's liver, kidneys, and pancreas. Blood tests can also detect and identify complex problems with a dog's internal systems, such as hormonal and chemical responses.


A urinalysis is a simple diagnostic test that measures the physical and chemical properties of urine. It is primarily used to evaluate the kidney and urinary systems, but it can also reveal problems with other organs. All pets over the age of eight should have a urinalysis every year. A urinalysis may be recommended if your pet is drinking more water, urinating more frequently, or if there is visible blood in the urine.

Fecal Exams

Fecal exams are performed in a veterinarian's office and are used to diagnose and treat a variety of infections that may be threatening your pet's health. Because intestinal parasites can be transmitted to humans, having your pet examined annually protects your family.

Fecal exams allow veterinarians to detect intestinal parasites like hookworms and roundworms. These can cause discomfort and irritability in pets and lead to more serious conditions. Because parasites can go undetected and infect other pets or people in the home, examining feces are the best way to detect them.

Magnetic Resonance Imaging - MRI

MRI has been widely used to help diagnose human health issues since the early 1980s, but veterinary MRIs have only recently become more widely used.

MRI scans can provide high-resolution images of soft tissues like the brain, spinal cord, ligaments, tendons, and abdominal organs to detect injuries and diseases. They are more detailed than other diagnostic imaging tools such as x-rays or CT scans.

If your dog or cat is limping, lame, having seizures, experiencing joint pain, neck pain, back pain, or paralysis, an MRI may be recommended to help diagnose the cause of your pet's symptoms.

Dog and cat MRIs take between 45 minutes and an hour to perform. To ensure success, a general anesthetic is administered before the scan. Vets recommend blood tests and x-rays be done before the MRI to ensure the pet is strong enough to be put under general anesthetic.

Note: This post is for informational purposes only. Rancho Park Veterinary Clinic is unable to offer CT scans and MRIs at this time.

Are you curious about diagnostic imaging for pets? Does your dog or cat have an upcoming test? Contact our Los Angeles veterinarians today for more information or to book an appointment.