Hi Jamie,

If Metformin doesn't work then we look at the other medication options but the first 3 ways to reduce insulin are:

If insulin does not respond to those 3 items or there are other indications medication is needed then the next steps are:

As you've already addressed diet and exercise for a horse with compromised feet isn't recommended you're at the steps of 'reduce ACTH' and Metformin.  If those don't work then you would look at Invokana as an option, but you're not there yet.