Equine Piroplasmosis

 

Equine Piroplasmosis - An Exotic Threat

The Atlanta equestrian Olympic events highlighted some problems that face Australian authorities in the import of horses for the Sydney 2000 Olympics. Concern about piroplasmosis, prompted the US magazine The Horse to run a special feature supplement concerning the problem. A few of the important points from this article have been distilled for readers of RIRDC Equine Research News.

Piroplasmosis is caused by protozoa, which is a type of parasite that lives in the blood. The organism lives in horse red blood cells and is spread mainly by ticks. There are two main types of organism: Babesia equi and Babesia caballi, which are widespread throughout the world. The only countries known to be free of the disease are the USA, Canada, England, Ireland, Japan and Australia.

Horses with disease may show mild non-specific signs such as depression and lack of appetite, while in severe disease there is elevated temperature and horses become anaemic due to destruction of the red blood cells. one of the problems is that horses can carry the parasite for many years without showing signs of the disease.

The disease caused a major headache for authorities in the US state of Georgia, because the habitat was favourable to ticks and there was potential for horses carrying the disease to spread it to other horses in the state. However, Tommy Irvin, the Georgia Commissioner of Agriculture, decided on a quarantine facility, where any risks of ticks were virtually eliminated. All horses that tested positive for piroplasmosis had to be identified in advance and were given special quarantine attention. Fortunately, research has indicated that only 6% of horses testing positive for piroplasmosis are actual carriers of the problem. However, finally the decision was made not to allow piroplasmosis positive three-day event horses compete. only dressage horses and showjumpers that tested positive on blood tests, were allowed to be imported into the US for the Olympic equestrian events.

The Georgian authorities instituted a rigid 20 point quarantine plan to deal with horses that were positive on blood tests for piroplasmosis. Such a plan will have to be considered by Sydney authorities, although the risks for the disease spreading are probably less serious than those in Atlanta.