I have been feeding equine products to my dogs for several years.
Our vets support this idea and the equine products are cheaper than the canine ones.
Our GSD was on Cosequin for a number of years and was active until she was into her 14th year.
I used to feed Cosequin powder to both horses and dogs.
However, it is not available here in Canada any more -- only from the vet and it is twice the price as in the US.
So, after having wonderful success with 'Recovery EQ' with one of my horses, I have switched Nixon on to that.
Currently I am only giving the Recovery to Nixon. He is 7 and had over 130 races.
I am not giving Ruby (5 and did not race as much) or NIgel ( just turned 4 and was a racing drop-out) any joint products at all.
'Recovery' does come in a 'canine' version, but the manufacturers and my vet have confirmed that the equine version is the same product. Different packaging. More money.