I have an update to another post about this issue. To date, I have been giving my poor old dog 1/4 large carrot chopped up over his dry dog food, a half tsp. of this glucosamine powder with Omega 3 6 9 also.
No anal gland stop ups ever so far on this routine every day!!!
My old beagle mix dog would get this all the time. Drove me crazy. What works finally is always give him 1/2 of a chopped up carrot over his food. I also give a squirt of the salmon oil so he won't scratch anymore. I had tried apple for many eyars but noticed his glands would always get blocked anyway. Switched to carrot and it has been much much better! Let us reduce the vet's salary:).