More than five times the number of horses running in the Melbourne Cup have died on Australian tracks this year, activists say.

In the past 12 months, 127 horses have died on Australian racetracks and thousands more have disappeared from the sport, the Coalition for the Protection of Racehorses says.

Statistics from Australian Racing show on-track deaths account for less than one per cent of all race starters this year and the deaths were down from 133 last year.

However, CPR claims thousands more are killed off track and out of the public eye.

"Many horses will sustain injuries and then simply disappear ... for most of these horses, our research has shown, that they end up being slaughtered," CPR campaign director Elio Celotto told AAP.

"Between 12,000 to 15,000 racehorses exit the racing industry every year ... most of them will be sent straight to the slaughterhouse."

But Racing Victoria says its safety standards are among the best in the world, spending almost $3.7 million on welfare.

"Racing Victoria's philosophy is that there is a home for every healthy thoroughbred," Racing Victoria CEO Bernard Saundry said.

"Over 90 per cent of Victoria's horses have been retired to the equestrian, pleasure and breeding industries."

The impact of horse deaths is also felt by their riders, Australian Jockey Association general manager Des O'Keeffe says.

"From the rider's point of view, the relationship they often have with the horses that they're riding is a really special and unique relationship," Mr O'Keeffe said.

Although no jockeys have died in races this year, two riders have been killed on Australian tracks during out of race activities.

"When riders are going 60 kilometres an hour on a 500 kilo animal, in a field 10, 12, 14 or tomorrow 24 runners it is an inherently dangerous sport," Mr O'Keeffe told AAP.