I would start by replacing all the TC Senior with Stabul 1. Replace the hay with the cubes. Keep everything else the same for now. See if he will accept the cubes just lightly wet to start. The water makes a big difference.

The possible issue with poor chewing forces affecting fermentation is more likely to affect TG than insulin. With fermentation, butyrate (low levels with the things we are talking about) primarily feeds the intestinal cells. Propionate, also low levels, can be converted to glucose but won't be unless blood levels are low. Acetate, the major fermentation production, can directly enter the TCA cycle so is a substitute for the glucose that the Invokana is causing to leave the body in the urine but it won't trigger an insulin response like glucose does and if the energy generation stays on track, TG won't be released.

Digestion/fermentation begins with effective chewing to reduce the food to small particles which enzymes, bacteria and protozoa can attack from all sides.  As horses age, the angle of their chewing surfaces changes so even if the teeth look good on exam the force of chewing is decreased. If there has been aggressive dentistry, it's even worse.
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Eleanor in PA

www.drkellon.com 
EC Owner 2001
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