CT is a specialised form of X-ray scanning providing detailed cross-sectional images of bone and soft tissue. A contrast agent (dye) may be injected into your horse’s bloodstream or a synovial structure to further highlight soft tissue abnormalities. Your horse will be under general anaesthesia for the duration of the CT scan. The gantry size limits scanning to the limbs and head of the horse.

There are multiple reasons why your horse might need a CT scan. It is used to obtain an accurate diagnosis for a cause of lameness that has been localised by your veterinarian. There are many causes of lameness that cannot be detected by x-ray or ultrasound, particularly within the foot. CT scans of the head are very useful for diagnosing dental and sinus problems, or injuries to the skull and cervical spine.

Alternatives to CT include Magnetic Resonance Imaging (MRI), ultrasound and standard radiography (X-rays). MRI can be more useful than CT in some cases because it allows better visualization of soft tissue structures in certain areas. However, there is currently no equine MRI available in New Zealand. CT offers the advantage of achieving excellent detail of cross-sectional images of bone and soft tissues, particularly when intra-arterial contrast material is administered. The acquisition times for the scan are rapid which limits the time the horse is anaesthetised.

CT works with x-rays, which is a form of radiation. Your horse will NOT be exposed to enough radiation during the CT procedure to incur risk of radiation damage either immediately or later in life.

General anaesthesia of a horse always carries some risk, and the team will discuss these with you. Risks must always be weighed against benefits gained by performing the examination.

A CT is usually recommended by your RVC equine veterinarian, or your own veterinarian from another practice. Other cases where a CT may be indicated are for abnormalities of the head or cervical vertebrae.

Your veterinarian can contact the Equine Hospital at RVC to arrange an appointment to have the CT performed. The CT can usually be arranged within 1-2 weeks for routine cases, or within the week for urgent cases.

Cleaning your horse: Please ensure you horse is clean prior to arrival, this helps keep the hospital clean where the CT takes place.

Medication: If your horse is on medication, you should check with your vet whether it should be given on the morning of the procedure. Please bring the required medication with your horse.

Shoes: Removal of shoes from the limb or limbs to be scanned is essential as they will create artefact in the images. Preferably all four shoes should be removed prior to drop off.

If your horse is normally covered, you will need to bring a light cover for them. They are in the barn, but it will still get cold in the winter months.

If they are on a specific diet, you will need to provide the meals for while they are here.

A member of the hospital team will admit your horse, go over the consent form to ensure you understand the procedure and risks involved. They will discuss if any further treatment or tests are required and answer any questions you may have.

It is important you provide contact details, ensuring someone is available to answer a call from us in case urgent information is required.

Your horse will be admitted to hospital the day before the CT. This allows your horse to have time to settle in the new environment prior to the pre-anaesthetic checks and procedure.

After the CT they will be with us until the following day. During this period, they will be monitored while they recover from anaesthesia.

Your horse will be anaesthetised and will be monitored throughout the procedure by a vet and trained veterinary nurse.

During the CT scan, the region of interest will pass through the scanner on a purpose-built equine table and x-rays are rapidly taken as a helical scan. The scanning time takes approximately 30-60 seconds, with the entire procedure taking between 30-60 minutes. This information is processed by a powerful computer to create the detailed images.

After the examination your horse will recover from the anaesthetic in a padded recovery box. They are monitored during this time. Once they are up and stable enough to walk, they will be brought back to their stable. They will be offered food and water when fully recovered.

The CT images will be sent to a specialist radiologist for interpretation and reporting. If your horse has been referred by your veterinarian to our hospital for a CT scan, the report will be sent directly to your vet the following day. Once the report has been received your vet will contact you to discuss the findings.

Once your horse is ready to go home, they can return to their normal routine, pending results from the CT and advice from us, or your veterinarian. Further information:

Our team will advise you on the next steps and will arrange any follow-up appointments if required. If you have questions or concerns, please contact us on 03 313 7438.