Ultrasound scanning is an informative and harmless diagnostic technique which is excellent for viewing soft-tissue structures within the body as a moving image.
Our most powerful scanner is at Donnington Grove, which produces high definition images and is capable of Colour Doppler imaging, but we also have other ultrasound machines at our Thatcham and Tadley branches, plus portable scanners.
Body structures appear on an ultrasound image according to their composition. Fluid shows as black and soft tissues (like liver or kidneys) show as varying shades of grey or white. Air and bone, however, reflect all the sound waves, so only the surface of structures containing these can be seen and they block the view of deeper structures.
Hair traps air, which is a barrier to ultrasound. Animals usually must have hair clipped and an ultrasound contact gel applied to obtain a clear image, but most can be scanned without sedation or anaesthesia.
The best known use of ultrasound in humans is scanning during pregnancy. This is a service we can provide for animals to determine if they are pregnant and to check viability.
In dogs and cats, pregnancy can be detected with ultrasound from 21 days after mating, but is most reliable after 28 days. An estimate of foetal numbers can be given, but this is not completely reliable - foetuses can be hidden, or lost after the scanning date. In older foetuses, heart beats can be detected, but only the most obvious abnormalities can be identified.
Ultrasound is frequently used in the diagnosis of medical conditions, enabling us to view what is happening within the animal. Ultrasound gives different information to radiography, so the two techniques are often both used to obtain a full picture of what is occurring.
Ultrasound can also be used to guide minimally invasive biopsy techniques. A biopsy needle can be seen by the scanner and aimed directly at a pocket of fluid or a suspicious area of an organ to obtain a sample for further diagnosis.
Ultrasound scanning is the best diagnostic tool for examining the heart. The ability of the heart to function can be assessed directly on the moving images. In addition, Doppler imaging can measure the flow of blood within the heart and blood vessels giving even more information.
Cardiac scanning is a specialised skill. Many of our vets are able to perform a limited scan. Heidi Cooper is currently studying to gain more skill in this area and we now have a Cardiology specialist visiting the practice to see cases.