Lecia,

As long as he's doing well otherwise and not currently having a rapid weight loss it would be best to test while on the Invokana so you can see what's going on. That's a very low s/s hay. Do you know how much of it he is actually eating? What else is he eating? (I can't get your file to open.) What is his Invokana dose?

Is his manure black too?
--
Eleanor in PA

www.drkellon.com 
EC Owner 2001