Every year Pedigree airs commercials during the Westminster Kennel Club Dog Show - you've probably seen them. The company has a fundraising drive, and they add money to it from every bad of dog food sold. Once a year they open a period where they accept operational grant requests from shelters and rescues across the country. SIRRA has applie for and received such grants for the past three years.
If you have a 501(c)3 non-profit organization that rescues dogs, you can apply too! The grant period is open till the end of September, I belive. The website is here: http://www.pedigreefoundation.org/.
The grant application is completed online; all you need are electronic files (PDF or WORD) of your Tax ID letter, the first page of last year's tax return, and a short note explaining how your organization operates. These files are easily uploaded during the application process. Other than that, it's checking a few boxes about how many dogs you help, the area you serve, etc.
So - if you run a non-profit org dog rescue, apply away! They are very nice and helpful. Thank you, Pedigree!