Diagnostic Imaging, Video Endoscopy & Pathology
Computed Radiography & Tomography (CT, CAT Scan), Myelography, Ultrasonography, Scintigraphy, MRI, Gastroscopy, Respiratory Tract Endoscopy & Pathology
Gastroscopy (‘Scoping the stomach’)
Gastric ulcers occur in up to 90 per cent of thoroughbred racehorses in training and are also common in racing standardbreds, show horses and eventers. Signs that might be caused by gastric ulcers include weight loss, poor appetite, poor performance and mild colic. Gastroduodenoscopy (‘scoping the stomach’) is the only definitive way to diagnose gastric ulcers in horses. In this procedure, a very long endoscope (a three-metre-long tube with a very small camera attached to the end) is passed through the horse’s nose and down its oesophagus to assess the stomach and the first part of the small intestine (duodenum). Following assessment of your horse’s stomach, recommendations can be made about treatment and diet that can help reduce or eliminate the effects of ulcers on your horse in the future.
Ulceration of the oesophagus can occur as a consequence of the gastric ulcer syndrome and we always assess the oesophagus during a gastroscopy. Oesophageal ulceration can also occur after an episode of choke (oesophageal obstruction), so we recommend that the oesophagus is evaluated in horses that have experienced choke, particularly if it has happened more than once.
Urinary Tract Endoscopy
Endoscopy of the urinary tract (bladder and urethra) can be performed in mares, stallions and geldings if they have abnormal discharges (such as blood in the urine) or if they are having difficulty urinating. Endoscopy is extremely useful in diagnosing uroliths (bladder stones) or other abnormalities that might be affecting your horse. In stallions, endoscopy can also be very useful in diagnosing infections of the accessory sex glands.
Respiratory Tract Endoscopy
Endoscopic examination at rest can be extremely useful in evaluating the sinuses, ethmoid region, guttural pouches, larynx (throat) and trachea (windpipe). Samples of fluid can be collected from these sites and submitted for examination under a microscope or culture to aid in establishing the cause of respiratory disease. Assessment of the pharynx and larynx (throat region) is an important part of the evaluation of horses that perform poorly or make an abnormal respiratory noise while exercising.
Dynamic Respiratory Endoscopy
Endoscopic examination of your horse’s throat (larynx and pharynx) while it is exercising on our high-speed treadmill enables us to monitor respiratory function while it is in work. This gives us a full indication of the extent of any problems when the horse is put under pressure so that we can make the best possible recommendations for treatment or management.
Imaging Techniques Available at the Equine Centre
Computed Radiography and Digital Radiography
The U-Vet Equine Centre uses both computed radiography and digital radiography systems to obtain high-quality x-rays of all parts of the horse. We have two roof-mounted x-ray tubes and a powerful generator that allows images to be obtained even in large horses. Most radiographs can be taken standing in sedated horses, including radiographs of the shoulder and thorax (chest). We also have the facilities and expertise to perform x-rays of the pelvis under general anaesthesia.
Standing Computed Tomography (CT, CAT scan)
The U-Vet Equine Centre is the only equine hospital in Australia to have a dedicated CT system for imaging horses standing, under sedation, without the need for anaesthesia. This system is only the third of its type in the world. It enables horses to be imaged very rapidly (scan time is approximately 30 seconds). It is capable of imaging both forelimbs from the carpus down to the foot, both hindlimbs from the hock to the foot, as well as the head and upper neck.
CT scanning uses x-rays to create a three-dimensional image of the area of interest. This greatly increases the information obtained and is therefore far more sensitive for identifying both bony and soft tissue lesions when compared with conventional (2D) x-rays. We are also able to image the whole body of foals, which has been extremely useful in identifying subtle changes in sick foals and allowing prompt intervention.
CT is the ideal technique for imaging the head and evaluating animals for diseases of the teeth, sinuses and nasal cavity. CT can also be extremely useful for assessing bone and soft tissue injuries in the lower limbs and we will often perform a CT for surgical planning or to obtain more information on a condition prior to surgery.
Myelography is an essential test to determine whether there is compression of the spinal cord within the vertebral column (spine or back bones). Myelography is performed with the horse under a general anaesthetic (ie, completely unconscious) and is most often performed to confirm cases of Wobblers disease.
Ultrasound is used primarily for imaging soft tissues, although it is also useful for bone surfaces. It therefore combines well with x-rays for investigation of limb problems. It can be used to investigate bone problems in areas where obtaining good-quality x-rays is problematic, such as the pelvis and spine. We also frequently use ultrasound to investigate heart, lung and gastrointestinal conditions. Nearly all horses referred for colic investigation undergo ultrasound examination of the abdomen.
Scintigraphy (Bone scan)
Bone scanning is the most sensitive technique for detecting bone injury available for horses. It involves the injection of a radiopharmaceutical that is taken up by areas of bone with increased turnover. A large camera (gamma camera) is used to image the horse and this detects ‘hot spots’ where there is injury.
The U-Vet Equine Centre Scintigraphy Unit has a proud history over more than 15 years of producing extremely high-quality images. Our qualified and very experienced nuclear medicine staff keep this sophisticated and sensitive equipment running smoothly and accurately. Over the years, we have accumulated a vast database of images with which we can compare each new case. Our current scintigraphy system, the German-made Equine Scanner H.R. Scintron, provides more sophisticated, efficient and user-friendly scans, with improved comfort and protection to equine patients.
We are able to perform scans on all areas of the body, from the feet to the head. Scintigraphy is especially useful for cases where the source of the lameness is difficult to localise, where the site of lameness has been identified but there are no changes on radiographs, where multiple sites of lameness are suspected, and for problems of the spine, pelvis and sacroiliac regions. The horse is usually admitted the day before the scan and, depending on results, is able to go home 24 hours after scintigraphy.
Magnetic Resonance Imaging (MRI)
The U-Vet Equine hospital has the only ultra-high-field MRI scanner in Australia for horses. MRI is the most advanced imaging technique currently available. It allows three-dimensional imaging of both soft tissue and bone, all at once. For horses, it is most valuable for imaging problems within the foot, because ultrasound imaging in this region is limited by the difficulty of penetrating the hoof.
Many horses have lameness that can be localised to the foot with nerve blocks, but radiographs are normal or show changes for which the significance is unknown. MRI is extremely valuable in these cases as the bones can be imaged in far greater detail, as well as the soft tissues. Common problems that occur within the foot that require MRI for a diagnosis are deep digital flexor tendon injuries, injuries to the collateral ligaments of the coffin joint, problems with the ligaments of the navicular bone, and navicular bone injuries themselves.
MRI systems are divided into low-field, high-field and ultra-high-field systems, based on the strength of the magnet. In general, the stronger the magnet (higher field), the more detailed the image quality and the larger the area that can be imaged. Although low-field systems allow imaging while standing and sedated, the disadvantage is that subtle changes may be more difficult to identify due to the smaller areas that can be scanned, the lower resolution, and problems with movement. High-field systems require general anaesthesia, but can image larger areas and provide better resolution, which may lead to more effective diagnosis.
The ultra-high-field system at the U-Vet Equine Centre can image the foot, pastern and fetlock, and cannon area of most larger-breed adult horses.