Ultrasound scanning is a painless procedure that uses high frequency sound waves (inaudible to humans) to produce images of structures within the body. When sound waves are aimed into the body, some are absorbed by body tissues and others bounce back. The sound waves that bounce back are measured by the ultrasound machine and are transformed into an image of a particular body area. Ultrasonography is most useful for visualising abdominal organs and the heart, it is much less useful (due to interference) for visualising bones and the lungs. We commonly use ultrasonography to identify pregnancy from about 24 days of gestation up until birth (although radiography is useful after 45 days to approximate the number of foetuses).
PREPARING FOR AN ULTRASOUND SCAN
Here are some important steps that need to be taken before your pet has an ultrasound procedure.
Do not feed your pet for 24 hours before their procedure. Fasting is important as a full stomach and intestines will make imaging organs around the stomach difficult (liver, adrenals etc). Water is permitted.
Please do not let your pet urinate within 3 hours before their study. A full or partially full urinary bladder is very helpful for a complete examination.
WILL YOUR PET NEED TO BE SEDATED?
If the patient is fairly bright and happy we will administer a short mild sedation, this allows the animal to lay quietly and comfortable for the ultrasound (which takes about 60 minutes). It will also be indicated if a tissue biopsy is required. We will inform you if there are any contraindications to sedation for example pregnancy testing (where sedation would affect the kittens/puppies).
A NOTE ON HAIR
After the procedure you may notice that your pet has been clipped. The hair on the abdomen (for abdominal ultrasound) or on the chest wall (thoracic ultrasound) will be shaved prior to the examination. This is necessary as the presence of hair obstructs the ultrasound waves and causes “blackout” on the picture. Blackout prevents us from obtaining the best possible view.