The female brindle-coloured dog had a broken front right leg and black football socks had been tied so tightly around her other three legs to cover sores from a severe skin condition that they had cut into them. She was also emaciated.
RSPCA inspector Rebecca Goulding said: “We believe her leg had been broken for about a week before she was found, and the socks had been on longer because the broken leg also had a wound where a sock had been.
“The poor girl is suffering from both sarcoptic mange and ringworm and was also emaciated. She was in a terribly sad state.
“She had to be sedated to get the socks off her.”
The dog - who has been named Susie - limped onto the forecourt of the BP Garage on Wakefield Road, Lepton at around 8.10am on Thursday, September 20.
CCTV footage captures her coming onto the forecourt from the Wakefield direction.
A member of the public called the RSPCA and took her to a nearby vets.
Inspector Goulding said: “She really is the sweetest thing, and hasn’t misbehaved once when she has been getting treatment.
“She was transferred to the RSPCA’s Greater Manchester Animal Hospital in Salford where everyone fell in love with her and has now been moved to an RSPCA branch where she has started to put on some weight.
“Her skin conditions, which are contagious, means she is having to be kept in isolation and is receiving daily treatment, and it looks as though her broken leg will need to be amputated as it had started to heal in the wrong position.
“She is far from out of the woods yet, but she is receiving the very best care and veterinary treatment.”
She wasn’t microchipped - as is required by law - so there is no way of tracing her owner.
Anyone who recognises her, knows who her owner is, or has any specific information that might help the investigation, is asked to call the RSPCA appeal line on 0300 123 8018 and ask to leave a message for Inspector Goulding.
Anyone wanting to donate to the RSPCA can visit: www.rspca.org.uk/give