For those who use WYSONG brand ferret food, they are offering 20% off
any order with the code 20MAR.
They offer a few varieties, including grain/starch free Epigen 90.
Here is part of the email I received:

Dear Valued Customer,

Enter the code 20MAR in the "Coupon Code" box at online checkout, or
mention the code over the phone to a Wysong customer service
representative (800.748.0188) for 20% off your next order.* (All Wysong
pet and human products are eligible. No minimum or maximum order.)

Jeff
In Loving Memory of Neo, Trinity, Morphy, Baby Girl, Dozer, Possum,
Pip, Pop, Sabrina, Minnie Mouse, Hunny, Misty, Frodo, Baggins, and
Mr. Parker Caring for Luna, Boomer, and Zoomer

[Posted in FML 7690]