Standing tall at 6ft 6in on his hind legs, Samson has ruptured a cruciate ligament in his left hind leg.
And now, his owners Ray and Julie Woods, from Wyberton, Lincolnshire, have forcefully postponed his 1,400 dollars surgery till the time the canine loses some weight.
According to vets, if Samson fails to reduce waist, he will not recover properly, and may never be able to walk again.
"The operation is on hold for the time being. But we have been told that there is a 90 per cent chance that he will need it in the next six months," the Telegraph quoted Woods as saying.
The 54-year-old resident of Wyberton, Lincolnshire, added: "If the ligament gets worse and goes completely he will need the surgery. But we are frightened if he has the operation he may not be able to get up again.
"It is a terrible thought because if he doesn't get up again, he may have to be put down."
On a normal basis, Samson is fed on 30 pound every week, and a turkey leg every day.
Now, Julie is hoping to get Samson fit with a regime of dieting, physiotherapy and hydrotherapy.
She said: "Samson has put on four stone since we got him - he is big but he is not a fat dog. It is important with big dogs that you keep their weight down.
"We feed him on dry food just twice a day, but he also has a turkey leg."