Rescue dog Rocco understands "sit", "stay" and "good boy" in sign language after being taught by staff at his rescue centre.
He lost his hearing after suffering an ear infection but has learned to respond to hand signals.
Staffordshire bull terrier Rocco, seven, was initially handed into rescuers in 2020 but was quickly rehomed with new owners.
However when one of the owners died and the other became seriously unwell he returned to the Llys Nini Animal Centre in Penllergaer, near Swansea.
Centre worker Sally Humphries said: "His new owners were really lovely and Rocco took to them straight away.
"I remember laughing at the fact he didn't want to come and say goodbye to me when I dropped him off. He stayed by their side like he'd known them all his life."
When Rocco returned, staff learned that he was completely deaf, so they started teaching him sign language.
Sally said: "He reads our hand signals and body language as a way of telling what we're asking for. For example, thumbs up means good boy.
"Most dogs are more in tune with our body language than our constant chitter chatter so it's not that tricky for a deaf dog to learn.
"It's all about consistency and making sure you choose a simple sign for each behaviour that you are trying to teach, so it's as clear as possible for them to understand.
"Rocco is a wonderful example of just how resilient animals can be and proof that you can definitely teach an old dog new tricks."
Staff hope the new skill will help Rocco find a forever home soon.
