Ultrasound scan in cats

An ultrasound scan is a very safe and useful way to look at some of the organs and structures inside your cat’s body. Unlike many other tests, it’s possible to see movement as it happens. 

Ultrasound works a bit like echolocation in bats and dolphins. A very sensitive piece of equipment (a probe) produces a sound that we can’t hear and then picks up what sounds return. By doing this thousands of times per second, a computer can turn the information into a virtual image. Images are focused in a small section, which has advantages and disadvantages.


What it’s for

What is ultrasound used for in cats?

An ultrasound scan is useful to get information about the shape, position, contents, and movement of many internal organs.

An ultrasound can be difficult to interpret, and both the quality of the equipment and the training of the person using it are very important.

The advantages are that there is no risk to the patient, little to no discomfort, and you can see different things compared to x-rays or other techniques. It is also a real-time image, showing movement and other changes.

Some disadvantages are that you can’t see large areas or objects in one image, and many things block the sound or disrupt the image, such as bones or hard faeces in the intestines.

Common things you can check with an ultrasound include:


  • Movement, shape, distension and inflammation of the stomach and intestines
  • Inflammation around the pancreas (pancreatitis)
  • Size, structure or masses of the kidneys, liver, spleen and gallbladder
  • Masses in the ovaries
  • Fluid or pus in the uterus
  • Stones, masses or inflammation of the bladder or ureters


  • Presence of fluid around the lungs or heart
  • Check the heart valves and muscle are working properly


  • Check the structures behind the eye

An ultrasound is especially useful to monitor chronic conditions, such as heart disease, due to how safe and dynamic it is. It can be repeated as necessary to see how things change over time and to detect problems early. It can also be used as a guide for some procedures, such as taking aspiration samples of the liver, spleen, kidneys or bladder with a needle.


How it’s done

How are ultrasound scans actually done?

A small amount of preparation is needed to improve the quality of the images, but most ultrasounds can be performed promptly and results are immediately available.

  • Tense muscles and shaking or trembling will make the image blurry. Very stressed cats may need a mild sedative to allow a thorough ultrasound. If the area to be looked at is painful, a strong painkiller is helpful.
  • Cat hair traps a layer of warm air between it and the skin. This air seriously disrupts the quality of the image, and in most cases, hair needs to be clipped short over the area being looked at.
  • A special gel is then applied between the ultrasound probe and the skin to improve image quality.
  • Most ultrasounds can be done with a cat lying comfortably on their back or side, but some require special positions. A nurse or assistant (sometimes the pet parent, depending on circumstances) will gently reassure the cat while preventing them from moving.
  • The person performing the ultrasound will then place the probe on the skin over the organ or area being investigated while analysing the image forming on the screen. Some time may be needed to find the best position for the probe. In most organs, several images are obtained using different angles and positions.
  • If a sample is to be collected, local anaesthesia may be administered, usually by injection. An antiseptic is applied to the skin. The target area is located using the ultrasound probe, and an instrument or needle is used to take the sample.
  • Most cats are ready to go as soon as the procedure is finished. If sedation was given, they may need to be monitored for a few hours before going home.



How much does an ultrasound scan cost?

Ultrasound procedures vary greatly in complexity and type of equipment required, ranging from checking if a cat has a full bladder to studying the speed and flow of blood inside the heart.

A standard ultrasound machine costs a few thousand pounds, but some procedures require special probes that can cost as much as the machine. Training and experience are also a big part of obtaining useful images. The cost of veterinary procedures also tends to reflect the average cost of living in the area.

All of this means the cost of specialised ultrasound exams can reach hundreds of pounds. Please discuss any cost concerns with your vet so that the best solution can be found for your pet.



Risks of doing ultrasound scans in cats

Ultrasound examinations are extremely safe, and the procedure itself is harmless. Anything that causes stress to an animal with severe breathing or heart problems has a chance to make things worse, but ultrasound is almost always the safest thing that can be done. It’s also safe for those performing or assisting, with the only risk being the pet reacting aggressively if the area being examined is painful.


Recovery tips

Recovery tips for an ultrasound scan in cats

Usually, the cat is completely normal during and after an ultrasound.

If sedation or a strong painkiller were necessary, your pet is likely going to need to rest and be monitored for a few hours.

Keep them in a quiet and comfortable environment if possible; they may also need help staying warm.


When to worry

When to worry

Speak to a vet straight away if your cat is:

  • Vomiting
  • Becoming less responsive
  • Having breathing issues after sedation or any procedure.

Our Joii vets are available 24 hours a day for advice if you have any questions.

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