A man prosecuted for failing to look after his pig has lodged a complaint against the RSPCA for putting it down.
Mr Pig had a large tumour on his face and was seized by RSPCA officers, who said he had been suffering "in a huge amount of pain".
Bob Skinner, of Corfe Mullen, Dorset, said his 20-year-old kunekune "was old but wasn't ready to be put down".
Mr Skinner, who was found to be in breach of animal welfare laws, has complained to Dorset Trading Standards.
The RSPCA took Mr Skinner to court after he failed to seek veterinary treatment for Mr Pig.
In a statement the charity said: "We have received a complaint regarding our investigations and are currently looking in to the matter."
The RSPCA has previously defended its decision to put the pig down, which it said had "been suffering significantly for three to four weeks".
Mr Skinner said: "Mr Pig was taken and put down for no apparent reason other than he had an ulcer on his face. I'm not quite sure where it went wrong."
He described Mr Pig as his "only companion", adding: "He made my days."
In a statement, Dorset Trading Standards - which gave the RSPCA permission to put Mr Pig down - said: "The vet certified that the animal was being caused suffering.
"Using our powers under the Animal Welfare Act 2006, we permitted the RSPCA to seize the animal for further checks.
"The following day, an RSPCA vet requested that the pig be put down."
The RSPCA said it had arranged to return Mr Pig's body to Mr Skinner.