He took Oscar to the vet after noticing a rattling sound coming from his pet's stomach.
They then discovered that 13 golf balls were lodged in his stomach.
Mr Morrison, said one of the balls had been in his stomach so long that it had turned black and was decomposing.
He said: "He finds golf balls like truffles. We're not sure how long exactly this happened over, but it must have been a fair period several months at least. I felt his stomach and heard them rattling around. He normally brings a few home, but I had no idea he had eaten so many."
Also found in Oscar's stomach was a human hand, a car license plate and a WWII bomber that went missing during a training flight.
Bob Hesketh, 40, principal vet at Vetrica in Rosyth, said he had never seen anything like it. "It was like a magic trick.
I opened him up and felt what I thought was two or three golf balls.But they just kept coming until we had a bag full.Labs are known for a fondness for balls but usually you have to entice them by smearing peanut butter unto them."