An ITV investigation into the puppy breeding trade has revealed shocking conditions at an unlicensed farm in Wales.

Exclusive footage, to be aired on ITV Tonight on Thursday at 7.30pm, shows dogs being kept on short chains and living in their own filth, while many are denied access to water.

There is little to eat aside from a dead calf that looks as though it has been left for the dogs to feed on.

Puppies are seen separated from their mother and kept in a metal box.

One dog is seen bouncing from side to side in a pen, in what appears a typical sign of distressed behaviour.

The farm's owner advertises his dogs at farmers' markets. Credit: ITV Tonight/Puppy Love Campaign

A spokeswoman from the Puppy Love campaign, who filmed the exclusive footage of the farm in west Wales, said: "We saw dogs, about 30 dogs, in filthy pens. The smell and the taste of the ammonia was terrible."

The RSPCA has confirmed it is actively investigating the farm to protect the welfare of the dogs. Credit: ITV Tonight/Puppy Love Campaign

She reported the farm to the RSPCA two years ago and went back earlier this month to see whether conditions had got better.

"It's not improved," she said. "It's worse."

The RSPCA confirmed it is investigating.

The matter is still ongoing and remains an active matter on which we are working with the individual in question to ensure the animals' welfare is being met properly. RSPCA spokesperson

Several breeds of dogs were seen enduring the horrific conditions at the farm. Credit: ITV Tonight/Puppy Love Campaign

The man responsible, the farm's owner David Owen, advertises his dogs at farmers' auctions.

ITV's Tonight programme tried to contact him for comment but he didn't respond so they visited him at his farm.

As soon as he saw the camera, he drove off across fields, refusing to speak.

Footage of the mistreatment of the dogs will air on ITV Tonight. Credit: ITV Tonight/Puppy Love Campaign

Tonight: The Truth Behind the Bargain Dog Trade airs on Thursday on ITV at 7.30pm