A huge animal rescue operation has taken place in Buckinghamshire after RSPCA officers found scores of neglected horses, ponies and donkeys.
Thirty-two horses were found dead at the site in Amersham on Friday and three other animals had to be put down.
RSPCA staff and vets described the scene as the worst they had ever encountered, one telling BBC News "it was utterly horrific".
The other 80 animals at the site have been transferred to horse sanctuaries.
RSPCA officers described how dozens of dead horses had been piled up against fences.
Rob Skinner, from the RSPCA, said: "I've seen some very gruesome things in the RSPCA in my time, but this is a very serious case.
"For this number of equines and the conditions the animals were kept in, it's a very bad case."
The RSPCA said the owner of the farm had been investigated by its inspectors before and that a tip-off from a member of the public had led officers to the site.
The Horse Trust is looking after many of the worst affected animals at The Home of Rest for Horses sanctuary in Speen in Berkshire, where they are being tested for disease.
Among them are ten young colts and geldings, a blind dun mare and three donkeys including a six-month-old foal.
Some were described as "grossly emaciated" and found tied up in small pens, while others have suffered with overgrown feet but are currently too scared to be treated by the farrier.
A spokeswoman for the charity said: "They were apparently standing in their own excrement and standing next to and on top of other dead animals.
"They were fully tethered and unable to move and deprived of food and water."
A spokeswoman for the Norfolk-based Redwings Horse Sanctuary, which has been helping with the rescue, said it had rarely seen horses in such a poor condition.
Other charities, including the International League for the Protection of Horses and Blue Cross, also took part in the operation to rescue the animals.
Nicola Markwell, Redwings Sanctuary communications manager, said it was the "largest" rescue in one day by the organisation, which was founded in 1984.
"It is quite unprecedented," she said.