Hi Kimberly,

You won't know if Metformin is indicated until you get your bloodwork results back.  We consider a horse with PPID well controlled when ACTH is in the lower 20s/upper teens at this time of year when ACTH is still at its lowest.  If your test results are higher than that or out of the reference range that's an indication that dosage of Prascend needs to be increased.  

For an IR horse we like to see insulin in the low teens with unfasted (hay only) testing.  Insulin over 80 is almost always associated with laminitis.  

Glucose usually will fall in the reference range unless a horse is diabetic which is very rare but does happen in some horses with out of control untreated IR. 

When you test your hay are you using Wet Chem or NIR testing?  Are you rinse/soak/rinsing your beet pulp?  How much should your horse weigh and how much does he weigh now?  How much is he eating?  I'm not sure who told you Equioxx isn't a NSAID but it most definitely is.  (From the BI site: EQUIOXX is a COXIB class non-steroidal anti-inflammatory for horses)

If you're administering it to help with pain relief it will not help with pain due to elevated insulin and if you are dealing with an abscess it will slow mobilization of the abscess so should be stopped ASAP. 

Getting your CH completed and current trim pictures will be very helpful for us to help you.