I'm with Mary Jane on trying the Bag Balm ... Doc came to me with multiple Corns on each foot (OUCH !) - two to three toes on each foot were affected. I think the extent of his Corns was one reason that his adoption group had a hard time placing him in a home. Not too many people wanted to adopt a lame, Thunderphobic dog.
Hulling each Corn and filling the holes left behind with Bag balm until they healed has worked wonders! I also massage Bag Balm into the pads from time to time. He is now almost corn free (has 1 teeny tiny one that is too small to hull, but doesn't bother him). This has been a year of true relief for him! He is sound enough that we can easily walk in parades, and walk for miles on hard pavement with no discomfort.
Before you amputate that toe, try hulling again, fill the hole with Bag Balm (put a baby sock on Mark to keep the Bag Balm on his foot and off your carpets and floors), and try this .....
Since the Bag Balm has worked well for more than 1 person here - I'd suggest that you try it.
Sometimes the simplest things are the ones that work.