Does anyone have a good supplement they've used for an older dog for their joints that they could recommend? 

My female springer, 13 yrs old, is having more and more difficulty doing the steps, and just moving around in general. The vet gave me Previcox, which really did absolutely nothing. It's a non-steriodal anti inflammatory, and extremely expensive to boot to learn it didn't work UGH!

In the past I've used Nupro powder supplement with some success, and I've had others swear by Missing Link Plus powder.  I've never tried the Cosequin tabs, or any of the "newer" arthritis meds OTC for the dogs so if you have any input on what I could try with her I'd appreciate it.

The poor girl has got to where she stands at the top of the steps and looks down them, then up at me, then back down and has to psych herself into going down the steps. She's 50 lbs or I'd carry her, and taking her out front doesn't work because she will not potty when on a leash (obedience training taken a bit too far in her mind) . I can't take her out off the leash because she is deaf and if she took off after a squirrel or a cat roaming she can't hear me call her back or tell her to leave it.

Yes indeed! Had my last pack on them, and currently, my lemonhead, Jim, who I believe is about 7 yrs old. I'm glad they are adding those suppiments to their doggie food these days as well.  Jim takes people glucosamine with MSM, cheap at Walmart.  Twice a day.