I strongly encourage you to keep a food log, if you’re not already doing so, to track your pet’s issues. It doesn’t have to be fancy - a spiral bound notebook that you get in the supermarket will do. You can use it to track behavioral changes or reactions to any changes (e.g. dietary, adding/removing supplements or changing brands of supplements, changes in dosing of supplements or medications, etc.). Doing this will give you something to refer back to, so you can better track changes or new/developing issues. It may also help you to find patterns to issues. Keeping a food log is how I determined Mr. Fluffy was developing an intolerance to the grain-free canned lamb cat food I was giving him.
My log included his litterbox habits as well as what he was fed. Following is an example. Items in parentheses are for your clarification:
6:20a ~¼ can WC C/T/CL (Wellness Core Chicken/Turkey/Chicken Liver) + 1/8 tsp probiotic
7:43a ¼ can WC C/T/CL + ½ cap lysine
Onite (overnight)/AM 1 good pee; 1 poop (2 < ave, 1 > ave [2x ave] turd)
~5:40p 4 very small duck Pure Bites - feeder
6:34p <1/8 can WC C/T/CL
7:14p > 1/8 can WC C/T/CL + ½ cap lysine
8p ¼ can WC C/T/CL + 1/8 tsp probiotic
9:13p 4 small duck PB (PureBites) - nail trim (reward)
9:14p 1 large cube canned pumpkin (for hairballs) + 5 rabbit treats
Brush/comb < 1 minute; 10:56p 1 oz Primal pheasant + 2-3 rabbit treats
Day/PM - 1 good pee; 1 poop (4 < ave, 1 > ave [~1.5 x ave] turd) - stinky
You will need to determine things like an “average” turd or a “good” pee. For Mr. Fluffy, an average turd was about an inch long, and an average pee was the size of a golf ball or larger. Anything bigger than that was a “good” pee. You can create your own abbreviations, but this gives you an idea. You can also note stool color (e.g. black, brown, etc.), if there was a hairball, vomit or regurgitation that day (I also noted this at the top of the page with the date for easy reference), etc.
You may want to have a list of the supplements, including brand name, on the back cover of the notebook. If you take the log with you to vet appointments (it never hurts to have it), you’ll have the information handy to provide to your vet.