I have show dogs and have been using this for Many years and have had no problem .I have been a CVT for many years also( too many to say)
I would start with a good blood panel and then a good food and cut the amount he eats with the green bean (Frozen, no canned) and Fiber One Cereal.
You usually see results with in a week or so, Remember a slow amount of healthy wieght loss and exercise!
Good Luck
Sparking Bly Yorkies