I read posts suggesting making quilts for dog beds in shelters. I have some fabric I want to cut and have a class do this as practice for binding.

What size should I cut.

(and please don't tell me there are small dogs and large dogs....lol)

Is there a uniform size.

I googled and found some instructions but it told me to measure the bed. Also most appear to be pillows.
Is there a use for a quilt type piece?

I would contact the shelter that you want to donate to.

In my binding classes I always give them a project to do at home for practice. I got a very large piece of quilted fabric that was a demo for a long arm machine. Am sure you know the type quilting. It's all over the place but is three layers. I hate to toss it and it occured to me it would make a good piece for practicing binding but would like the students to make something useful. I thought of pet quilts.

What if you went to a website like PetsMart and looked at the size of Dog Beds. Just a thought... My poodle gets all kinds of things I practice on.

Around 24" x 36" would be a good size for a mid size dog (40 - 60 pounds).

Mine are 27" x 36"

Sadiemae has a good suggestion. There's this site: http://www.snugglesproject.org/docs/SP_projectsheet.pdf, that gives you information on sizes, etc.

I would also recommend contacting a rescue or private shelter rather than your local animal control. I only recommend this because, having worked for one, I know that some facilities can't give their dogs beds due to their cleaning practices while others supply a foster network with beds. Chances are, a rescue that uses fosters will more readily be able to use beds than a large, kennel-style facility due to the fact that pens need to be hosed and disinfected daily.