COMPLAINTS have been flooding in to the RSPCA alleging cruelty is taking place at horse sales in Holmfirth.
But the animal welfare charity says it is powerless to act.
Its Huddersfield and district branch says it has received many complaints that some of the animals are being badly treated at the sales.
The sales take place regularly in Holmfirth cattle market.
They provide a chance for the travelling community to meet and trade horses, ponies or donkeys.
RSPCA spokeswoman Heather Holmes said: "Unfortunately, there is a minority who mistreat the animals."
Tim Bray, chairman of Huddersfield RSPCA, said: "People have seen the animals being hit with whips or sticks, or they have wounds that have not been attended by a vet."
But the RSPCA cannot prosecute an owner unless an animal has a serious wound that is causing pain, suffering and distress.
Mrs Holmes added: "You might have an animal that looks neglected but is not injured, so we can't act.
"We can offer advice to horse owners and sometimes practical help."
She said the Animal Welfare Bill - now going through Parliament - could become law and allow RSPCA inspectors to take action if they suspect an animal is being mistreated, rather than waiting for cruelty to happen.
Mr Bray welcomed the possible change. He said: "It will help. It is extremely frustrating that we cannot do anything about the complaints."
Kirklees Council's environmental health department is responsible for making sure health and safety guidelines are followed at the sales.
It also monitors animal welfare and makes sure there are the transport documents for the livestock.
Environmental health manager Andrew Sheard said the department had received just one report of animal cruelty.
"If people are complaining, they are not complaining to us," he added.
"Some animals don't look good, because they are at the end or their life and are scrawny and they go to the knacker's yard. Others are healthy and are sold for meat.
"It is a hard world and lots of people would like to see animal sales banned altogether."
Mr Sheard added that the market had an animal welfare officer.
To report animal cruelty, phone the RSPCA on 08705 555999.
To report incidents specific to Holmfirth horse sales, contact Kirklees's environmental health department on 01484 226400.