knuckled paw and leg stiffness

[Helenjm]

6 weeks ago my healthy 12 year old staffie-cross developed a limp in his front left leg. In the 6 wks til now it has gone from a limp, to stiff leg, to not picking paw up when walking, to now having a knuckled paw and walking on 3 legs. At first my vet thought arthritus and he was given metacam and advised gentle 10 min walk, butnow she's thinking bone cancer or damaged nerve. I don't think ita a damaged nerve as, although he's detiorated quickly, I've seen the changes and its not like he's trapped his foot or anything, And he's not a sociable dog so doesn't run off the lead, unless i'm sure no other dogs are around which hasn't been for good 12months. He's now been given  24 hour dose of vetergesic and 7 days of tramadol to go with the metacam and total rest. Does anyone had any experience like this?

[Ghilly]

A paw that is knuckled under is definitely indicative of nerve damage or impingement of some type.  What is causing it is another story.  In the absence of your dog having injured itself, which may correct itself with rest and rehabilitation, the damage could be being done by something more sinister like a mass pressing on a nerve.  In the front legs, it's often a sign of a cervical (neck) problem.  Because your dog is advanced in years the scope of what the problem could be is considerably wider than it would be in a young, very active dog, when it would most likely be from trying to be over-athletic or playing too rough with another dog.  If you are able, I would take her to a neurological specialist to have MRI done.  That's the only really sure way to tell what you are dealing with.  An X-ray may or may not tell you, but MRI will.

Ghilly

[Margot49]

Has he been checked for any cervical or spinal problems? Might want to have some x-rays done.  
The only time I have seen knuckling ( if I understand correctly) was in dogs with Muscular Dystrophy but your dog would have shown signs long before now.

[Jerry_NJ]

I'm sure others like me have read and had no idea to offer.  That noted, I admit I am not sure what you describe as "having a knuckled paw ".  Is the paw turned back so that if the leg was put down, the foot pads would not contact the floor?  I guess there is an "ankle" such as we humans have.  That being the case it seems to me it could be a tendon or other muscle malfunction.  I'm sure those are not correct medical terms - but I am just trying to explore you problem.  

Did the vet consider any mechanical brace to straighten the paw to the normal position?  Muscle relaxant? Ace bandage....?

Hope you find a answer/fix, but 12 years for a dog is getting to the age where things just don't work right any more - I speak from a position of personal experience being a senior myself.