Sounds like you've done anything I can think of, Marcie. Keep an eye on it.
I'll check with a friend of mine, who knows a whole lot more about buns than I ever would. Or...see my signature....it goes to Bunspace dot com... which has a discussion forum where you can search or post for your concerns.
And thanks for being such a good bunny mom to your senior bun!
Paws up from my two 9 y.o.'s - Noah and Tasha.