> I now give them veterinary quality Glucosamine rather than the Holland and Barrett own brand.
I think the veterinary Glucosamine is normally Glucosamine HCL, the most common non-vet glucosamine is Glucosamine sulphate. The GlucHCL is more effective then the Gluc Sulphate, also the vets gluc generally has a higher dosage of gluc per dose, this is why the vets stuff is generally more effective.
I use Synflex (liquid glucosamine), a combination of Gluc HCL & Gluc sulphate @ 1250mg (not from the vets), it also contains chondritin etc.. I have found it to be great for my dogs ED. I swear by this stuff now :) It's a bit dearer than the little tubs of tablet suppliments you can get on-line, but still for Buster, 1 bottle will last 1 month (it's dosed on body-weight) and at about £13 per bottle I think it's a great buy :)