A sheep now has a dog collar and lead and sleeps in a basked with Jessie, a nine-year-old Springer Spaniel.
Alison Sinstadt, who runs Adderley Wharf Farm in Shropshire, bought lamb Jack into the house because he was very small and needed hand feeding.
However, Jack and Jessie then formed an unlikely friendship and they are now inseparable, with the sheep trying to bark like a dog.
Jack even goes so far as to try to herd up sheep when he is in the field with them, showing that he doesn't recognise he is a sheep.
"He even fetches sticks and jumps up on his hind legs like a dog. When we take Jessie for a walk on the lead Jack nuzzles me until I put him on a lead too," Ms Sinstadt said.
She added that the only thing that Jack doesn't do is eat dog food, with the sheep eating its normal diet of grass.