7 yr oldLab suddenly afraid of stairs

Question
We put our 7 yr old 115 lb Chocoalte Lab out in his yard and suddenly he is afraid to go up the steps.  He is VERY high strung and we finally coax him up  the 3 stairs with a treat but it takes about 15-20 minutes and he is yelping the whole time, which I'm sure bothers the neighbors.  Any suggestions??  I am really frustrated.

Answer
I would get him to the vet on Monday unless the problem goes away.  For now, give him some aspirin, Buffered aspirin if you have it, but none of the newer stuff.  The dose is 5mg per pound of body weight.  He is big enough that will be almost 2 tablets every 8 hours.  Be sure and tell the vet you gave him aspirin.  

He could have pulled a muscle, or it could be arthritis.  I am concerned about his weight.  There aren't many Labs that should weight 115 pounds.  Being overweight could lead to early joint problems.  Your dog definitely should be narrower at the waist than the hips and chest. You should be able to easily feel the ribs, but not see them. Each dog is different. Standard recommendations are a good place to start, but each dog must have its food and exercise adjusted to its individual needs. Here is a link to a good illustrated guide, http://www.longliveyourdog.com/twoplus/RateYourDog.aspx

Can you rig up a ramp or something for him?  I use a piece of OSB board to make it easier for my 14 year old to get in and out of my truck.