Thirty dogs with fur so matted their breeds were unrecognisable, and many covered in faeces, were found in a neglected state in kennels outside a property in the Skegness area.
The RSPCA was alerted to the plight of the dogs last week and the owner agreed to sign the pets over into the care of the animal welfare charity.
The dogs were taken by rescuers for immediate veterinary attention. Several of them were so badly matted that they had to have their fur shaved off.
The matting had caused skin problems for some of the dogs. Many also needed emergency dental work to enable them to eat properly.
One dog had pus leaking from her mouth and the situation reduced the rescue staff to tears.
The dogs were all cross-breeds and included Dachshunds, Yorkshire Terriers, Toy Poodles and German Shepherd types.
All the dogs are in need of care and rehabilitation from the RSPCA. When they are ready they will then be rehomed at a later date.
Ella Carpenter, manager at RSPCA Radcliffe Animal Centre in Nottinghamshire, said: “Clearly the dogs had been neglected for a significant amount of time and required their coats to be completely shaved and urgent dentals to be carried out. They were unrecognisable as to their breeds.
“One dog was in such a state she has pus leaking from her mouth. It was so upsetting to see it reduced rescue staff to tears
“Thankfully, dematting and removing the vast majority of their overgrown fur has already given the dogs a new lease of life.
“They are now able to move freely without experiencing the pain of those heavy matts, glued together with excrement, pulling and tearing at their skin.
“We will continue to regularly bathe them to help improve their skin condition and we will spend the coming weeks rehabilitating them and will give them lots of care and attention so when we are ready to re-home the dogs we can match them with a perfect future owner.”