With the Sport of Kings being a multi-million dollar industry, its no surprise that horse racing in particular has embraced nuclear science with zeal, in a bid to keep their top-class equine athletes "on track". Horses, like human athletes suffer from a wide variety of stress fractures of the bones, but for horses this damage can have fatal consequences.
After nearly a decade of use in hospitals, the gamma camera is finding new uses in diagnostic animal nuclear medicine, in this case, for diagnostic treatment of bone fractures of our top thoroughbreds.
The way it works is fairly simple. The horse is injected with a mixture of an ANSTO-produced radioactive isotope like Technetium-99 and HDP, or Hydroxy Diphosphonate, an inorganic binder.
The Technetium-99, which is produced using ANSTOs HIFAR research reactor, at Lucas Heights, is one of the most commonly-used radioisotopes for this purpose and may yet become as useful for animals as it is in the diagnosis of human ailments.
The Technetium carries the HDP directly to the surface of the bone through the muscle and ligament layers. The isotope gives off radiation and the gamma camera translates this into a "snapshot" of the bone and a picture of the horses health can then be analysed.
Weighing in at 400 kilograms, or almost as heavy as the equine itself, the gamma camera is used in the early detection and treatment of bone stress fractures and other degenerative bone diseases that could be the difference between a potential cup winner or a visit to the glue factory!
There is no danger of radioactivity to the animal, as Dr. Jonathon Lumsden (veterinary surgeon) of the Randwick Equine Centre in Sydney points out, "the whole procedure gives off about as much radiation as an ordinary chest X-ray."
The Randwick Equine Centre is the only veterinary surgery in NSW that uses this technique and so far it has proved to be a resounding success. Dr. Lumsden, a specialist in equine surgery, says that " the whole technology has been adapted from human use with the aim being to provide a physiological picture of the bone, rather than just the structure, like X-rays or ultra-sound." In other words, the gamma camera produces a picture of what the bone is actually doing.
The practice, which sees about four horses a week and charges $900 for the procedure, is not only using the gamma camera for racing thoroughbreds, but for other athletic equines, such as dressage, event and jumping horses. Although, he admits, "seventy-five per cent of the animals we diagnose here are racehorses."
According to Dr. Lumsden, the gamma camera procedure may well be a lot more important than most people realise. He says, that during a recent post-mortem study carried out by the University of California, "a majority of horses with fractures to the pelvis led to fatal consequences."
This procedure, he goes on to explain, " has a number of advantages over traditional X-rays or ultrasound, among them being, the ability to detect micro-fractures around joints and the ability examine to upper body of the animal. "Conventional methods", he says, "just dont give these kind of results."
He goes on to say, that the camera is a "very useful tool."
Asked as to whether any famous Melbourne Cup winners have gone through the gamma camera treatment, Dr. Lumsden replies " Saintly and Doremus come to mind, although I'm not sure if there were any others."
The gamma camera is proving to not only be a potential lifesaver for humans, but also one for the animals we use for sport. The procedure may well be a simple one, but its one that's also saving the lives of our favourites as well as the outside chances in the Sport of Kings.
Published: 27/10/2000