Dog & Cat HospitalCalabasas

Patient Education

Abdominal Ultrasound

Abdominal ultrasound lets our veterinarians look inside your pet's organs in real time — visualizing texture, blood flow, and structural changes that X-rays simply can't show.

Abdominal ultrasound is a non-invasive imaging study that uses high-frequency sound waves to create real-time images of the liver, spleen, kidneys, adrenal glands, pancreas, intestines, bladder, lymph nodes, and reproductive organs. Unlike radiography, which shows organ size and shape in outline, ultrasound reveals the internal architecture (parenchyma) of each organ — nodules, cysts, masses, and changes in tissue texture that a shadow on an X-ray cannot characterize. At Dog & Cat Hospital Calabasas, abdominal ultrasound is performed on-site and is frequently used alongside bloodwork and radiographs to build a complete diagnostic picture for ill dogs and cats.

Why It's Recommended

Ultrasound is particularly valuable when bloodwork or X-rays suggest an abdominal problem but don't fully characterize it. It is recommended for:

  • Elevated liver enzymes, kidney values, or abdominal mass found on exam or X-ray
  • Unexplained vomiting, diarrhea, weight loss, or abdominal pain
  • Suspected splenic masses, adrenal tumors, or lymphoma
  • Staging a known cancer to check for spread to abdominal organs
  • Guiding fine-needle aspirate (FNA) or biopsy needle placement when tissue sampling is needed — ultrasound guidance makes the procedure safer and more accurate
  • Evaluating for fluid in the abdomen (ascites or internal bleeding)
  • Monitoring a known condition — kidney disease, Cushing's disease, or a previously identified mass — over time

What It Detects

Abdominal ultrasound provides detailed information about each organ system:

  • Liver: nodules, masses, diffuse changes (hepatitis, lipidosis, cirrhosis), bile duct enlargement
  • Spleen: masses (splenic hemangiosarcoma is common in large-breed dogs), congestion, torsion
  • Kidneys: cysts, hydronephrosis (fluid dilation), stones, infarcts, and structural changes of chronic disease
  • Adrenal glands: enlargement from tumors or hyperplasia associated with Cushing's disease
  • Pancreas: pancreatitis (inflammation), masses, or cysts
  • Intestines and stomach: wall thickening, layering loss (suggesting infiltration or cancer), lymph node enlargement
  • Bladder: polyps, masses, stones, and wall changes
  • Reproductive organs: uterine enlargement in pyometra, ovarian masses, prostatic disease

Concerned about what's happening inside your pet?

Book an Appointment

How It Works

Abdominal ultrasound is performed with the pet lying on a padded table or cushioned trough:

  • The fur over the abdomen is clipped (or wetted) to improve contact between the probe and the skin
  • Ultrasound gel is applied to improve sound transmission
  • The transducer (probe) is pressed gently against the skin and moved systematically across the abdomen to image each organ in sequence
  • The veterinarian observes real-time images on the screen, measuring structures and documenting any abnormalities
  • If a mass, node, or organ needs sampling, a needle can be guided into the target in real time under ultrasound visualization — far more accurate than blind aspiration

A full abdominal survey typically takes 20–45 minutes depending on the complexity of findings.

Preparation

A few simple steps help ensure the clearest images:

  • Fasting: 4–6 hours without food is recommended before an abdominal ultrasound; a full stomach causes gas and fluid that obscure views of the liver, pancreas, and intestinal walls
  • Full bladder: for optimal bladder imaging, avoid having your pet urinate immediately before the appointment; a moderately full bladder improves visualization of bladder wall and contents
  • Fur clipping: a small area of the abdomen will be clipped; for very hairy dogs, this may leave a visible patch that takes a few weeks to grow back
  • Sedation: most pets lie still for ultrasound without sedation; anxious, painful, or very squirmy patients may benefit from a light sedative to improve image quality and minimize stress

What to Expect

Ultrasound is a gentle, painless procedure for the vast majority of pets. Your dog or cat will be placed on a comfortable padded surface; a veterinary technician holds them still while the probe is applied. The gel is slightly cool but causes no discomfort. Most pets relax within the first minute once they realize nothing hurts. If a fine-needle aspirate is performed during the same visit, a brief needle stick is involved — equivalent in feel to a vaccination. Results are discussed with you immediately after the study. In complex cases, images may be transmitted to a board-certified veterinary radiologist for a formal consultation report, returned within 24 hours.

Is It Safe?

Abdominal ultrasound uses sound waves — there is no ionizing radiation involved, making it safe to perform repeatedly and in patients where radiation exposure should be minimized, including pregnant animals, young pets, and those requiring frequent monitoring. There are no known adverse effects from diagnostic ultrasound in dogs or cats. The brief needle stick involved in a fine-needle aspirate carries a very small risk of minor bleeding at the puncture site, which is monitored. Ultrasound-guided sampling is significantly safer than blind aspiration because the needle position relative to blood vessels and other structures is visible in real time.

Frequently Asked Questions

1What is the difference between an abdominal ultrasound and X-rays for my dog?
X-rays show the size, shape, and position of organs in silhouette — they're excellent for detecting changes in outline and density (stones, gas, large masses). Ultrasound reveals the internal texture of organs in real time — it can find nodules inside a normal-sized liver, differentiate cysts from solid masses, and guide needle biopsies. They work best together.
2Will my pet need to be sedated for an abdominal ultrasound?
Most dogs and cats tolerate abdominal ultrasound without sedation — the procedure is painless and non-invasive, and most pets relax within the first few minutes. Light sedation may be recommended for particularly anxious or painful patients to improve image quality and minimize stress.
3How long does a pet abdominal ultrasound take?
A complete abdominal survey typically takes 20–45 minutes for the imaging itself. If fine-needle aspirates are collected during the same visit, the total time is slightly longer. You'll discuss findings with the veterinarian immediately afterward.
4What does my dog need to eat or not eat before an abdominal ultrasound?
Fasting for 4–6 hours before the study is recommended because a full stomach causes gas that interferes with organ visualization, particularly the liver and pancreas. Water is generally fine. Try to keep the bladder moderately full by limiting urination for 2 hours before the appointment if bladder evaluation is planned.
5My dog's ultrasound found a mass on the spleen — what does that mean?
A splenic mass is a significant finding that requires further evaluation — it could be a benign nodule (common in older dogs), a hematoma, or a malignant tumor such as hemangiosarcoma. Fine-needle aspirate or surgical biopsy is usually needed to characterize it. Our team will walk you through the next steps and what your dog's specific findings mean in context.
6Can abdominal ultrasound detect cancer in cats and dogs?
Yes — ultrasound is one of the most sensitive tools for detecting abdominal masses, lymph node enlargement, and organ infiltration associated with cancer. It is a key part of staging known cancers and investigating unexplained weight loss, lethargy, or bloodwork changes. A biopsy or aspirate is usually needed for a definitive diagnosis.
7How much does a pet abdominal ultrasound cost?
Cost depends on the extent of the study (targeted organ vs. full abdominal survey) and whether fine-needle aspirates are collected. A radiologist consultation adds to the cost but provides specialist-level interpretation. We'll provide a clear estimate before the study. Contact our team for current pricing.
8Does my cat's fur need to be shaved for an ultrasound?
A small area of the abdomen is usually clipped because fur traps air that blocks sound waves. In short-haired cats the clipped area may be minimal. For most pets the fur regrows within a few weeks.

Concerned about what's happening inside your pet?

Abdominal ultrasound gives our team a real-time look at your pet's organs — often providing answers the same day that change how we treat and monitor your pet.

Book an Appointment