My rescue whippet who is now five years old was malnourished in utero and has spine problems which resulted in back knee problems : surgery now arthritis etc. "normal" meds make him sick to stomach and I have read about their dangers and do not want to use them. ( visits to the chiropractor help a bit ) I want Natural treatments : your opinion on glucosamine, msm, vitamin c, ( primarily essential fatty acids ) and other natural remedies please - I would like serious detailed information such as recommendations and how much and when to administer -