I am using a liquid called Flexicose Liquid Pet JointCare. For a small dog, you only need a teeny tiny amount so a bottle would last a long time. I am giving it to Brea (my tiny one) cause of the hip surgery she had and the LP in her other leg. I also use it for my Dane.
They both like it and it hasn't caused any problems for us.
I actually got mine on e-bay but there are lots of places online you can buy it too.