Horse researcher still racing clear of the field

Dr Chris Pollitt, a reader in veterinary science at the University of Queensland, has won the 1997 Rural Industries Research and Development Corporation-Vetsearch Equine Research Award.

Dr Pollitt has gained a worldwide reputation for his pioneering research into the devastating equine disease laminitis - the second biggest killer of horses after colic.

The tissue connecting the foot bone to the hoof is continually breaking down and renewing itself, an essential process as the hoof keeps growing much like human fingernails.

However, laminitis occurs when that connective tissue starts to disintegrate. The bone then separates from the hoof and can eventually penetrate the sole of the horse's foot.

Laminitis normally affects all four feet and is extremely painful and distressing. While mild to moderate forms can be treated with varying degrees of success, many horses have to be destroyed.

Dr Pollitt said laminitis affected about two percent of all horses. "The onset of the disease is very swift - as little as 36 hours - and usually strikes while the animal is vulnerable because of some other infection or sickness," he said.

Dr Pollitt's research has identified the enzymes believed to cause the uncontrolled breakdown of the connective tissue inside the hoof and he is now testing a new British drug which may block that process.

Much of the research is taking place in test tubes where laminitis is introduced to hoof fragments and the enzyme is chemically activated. "We're still looking for the trigger," Dr Pollitt said.

The blocking drug being used is the one currently under trial in the U.K. to prevent the spread of malignant cancers in humans. Dr Pollitt believes he is the only person in the world testing it against this crippling equine disease.

"The drug won't cure laminitis but my goal is to develop a means of prevention. We need something we can inject when a horse is being treated for other problems which expose it to the risk of laminitis," he said.

In 1995 Dr Pollitt published his internationally acclaimed Color Atlas of the Horses Foot which has become a standard text for veterinarians and horse owners around the world.

In this and numerous other publications, Dr Pollitt examines the anatomy and physiology of the horse's foot, and more recently he has produced critical work on blood flow and its change with laminitis.

Dr Pollitt said he seemed to be almost alone in suggesting that laminitis was connected to an increase of blood supply to the feet; the popular belief was that a decrease in blood was a contributing factor.

Part of his latest research is into the effect of icing the horse's leg using a specially designed boot. This traditional first-aid measure will reduce blood supply and, Dr Pollitt believes, provide added protection against whatever triggers the destructive enzymes.

"My research at the moment ranges from the practical (the ice), through test tube experiments to the most sophisticated techniques of molecular biology in an attempt to understand the nature of laminitis at a cellular level," he said.

Dr Pollitt is also experimenting with the development of a special video camera, 'hoof-cam', to study changes in circulation as they happen.

The technique involves implanting a tiny prism into the horse's hoof. A layer of minute blood vessels in the foot slot into a groove in the prism and a light will then reflect images back to a video camera attached to a specially designed horse shoe.

Dr Pollitt said this device would enable him to study the blood supply in the foot and see what constricted and what dilated blood vessels. The eventual aim was to find ways of controlling blood supply and specifically more effective means of achieving blood vessel constriction.

For further information, contact Dr Chris Pollitt (telephone 3365 2063; mobile 0419 721 682).