Re: Questions concerning recent PPID diagnosis
As far as the current diet, we recommend a TOTAL intake of hay and concentrates that is either 1.5% of current weight or 2% of ideal weight - whichever is higher. For a horse that's meant to weigh 900 pounds the higher of those two amounts is 18 pounds a day which is 7 pounds less than you are currently feeding.
Before looking at Thryo-L my suggestion would be to get the diet tighter - if you're using the ODTBC to carry supplements, can you do less?
Brooks Enhancer - if the numbers here are correct (https://madbarn.com/feeds/enhancer-brooks-feeds/) this is not a suitable feed for an IR horse and based on their own feeding chart (http://www.brooksfeeds.com/pdf/products/Enhancer.pdf) you're feeding much more of it than needed. It would be best to cut that out completely and have your hay balanced to determine what vitamins/minerals are needed for Tricana.
Then, whatever the difference is between the amount of ODTBC you're using and the 18 pound total can be made up in hay, but it should be weighed so that Tricana is only eating a set amount each day. That should help with weight loss without needing to add in Thyro-L.