Many of the long-haired animals – which looked like household pets – were pawing at the bars in a frantic effort to escape when investigators discovered them, it’s claimed.
The activists say the dogs were found alongside dozens of foxes that were destined to be killed for their pelts.
Many animals did not even have access to drinking water or food, and two of the rusty cages had rotting corpses inside, according to the witnesses.
“We were shocked,” said an investigator from animal-welfare group Open Cages. “It was appalling to see the animals in so much fear and distress.”
The activists filmed an initial rescue of six dogs – one with a broken leg – and four foxes, taking them to be treated by vets. They later returned and saved 11 more animals.
They are still investigating the farm, in south-western Poland, in an attempt to have it closed down.
It was not clear why dogs were being kept at the farm or whether any had been slaughtered for their fur.
The owner told the activists he was keeping the dogs to scare off thieves, but it was not clear how they could do that from inside cages, the group said.
Some foxes were seen in the video racing up and down their small cages in distress.
“Appalling conditions like this are not unusual in the fur industry,” the investigator said.
“Millions of animals are slaughtered every year for their fur. The cramped conditions, and isolation of individuals, makes this industry unavoidably cruel.
“For animals that are adapted to roam vast distances every day, living in a tight cage is torture.”
Fur farms have been banned in the UK since 2000, but it’s estimated that since then Britain has imported more than £650m worth of animal fur.
Vets, animal-behaviour experts and Springwatch host Chris Packham have called for the UK to stop supporting the trade.
Rescuers said at least one fox needed an amputation because of painful foot abscesses.
Connor Jackson, chief executive of Open Cages, said: “While it is outrageous to see beloved dogs kept in cages on fur farms, this is a reality for terrified foxes and minks daily – until they are violently killed and skinned for their fur.”
Fur trade chiefs said the farm was not legal and that they had notified prosecutors that the farm may have been conducting illegal breeding.
But Open Cages said the farm was legal as it was “in the register of the main veterinary inspection”.
Fur farms have been accused of causing not just agonising physical injuries and infections that go untreated, but also psychological stress and even cannibalism.
Some of Britain’s most upmarket department stores and fashion websites still sell fur clothing.
The Independent could not contact the farm, but the Polish Fur Breeders’ Association said it was shocked by the “disgusting” way animals were treated there.
The farm owner, an 83-year-old, also kept cats and goats, and was not a member of the association, a spokeswoman said.
Daniel Chmielewski, chairman of the association, said the place had been a fox farm but it was no longer officially registered as such and not subject to state checks.
“We do not have information about how many animals have been kept on this farm as it is not a functioning fur farm but I assure you local authorities are handling the case, as they do in all cases of animal neglect.
“There exist no incentives to farm dogs and cats for their fur in Europe. The sale of pelts, as well as farming of dogs and cats for fur, is strictly forbidden by EU law.”
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