Codie Rae said
A quick search of images shows that calipers tend to measure in centimeters, not inches. So that could be why the number seems larger than it should be. No way would a pittie foot be larger than an XL bootie size.

HAHAHAHAHHA I had the vet tech do it, and she's the one that pulled out the caliper and told me "4.25 inches" hHAHAHA oh my god when we go in tuesday I'll have to look at the caliper and read it hahahahahahhahaha oh man that is too good. Much appreciated help because I thought I was doing this right!!! 

and as far as the pittie foot being too big, that's what i've been saying this whole time! even as far as pits go, i feel like eva's feet are so teeny, so I can't imagine them being "too big" for literally anything.

midnighter94 said
When I measured Murphy for the pawz boots, I got his foot wet and had him step on a piece of paper so that I could measure the wet footprint.  I think he wears the medium ones, but they aren't for long-term wearing, just once in awhile use, like when we go out to MSU.  Maybe you could try that way?

Donna

The wet footprint idea is so smart! I also just want them for going to slippery places or when she insists on going into the rocky water at Elizabeth Park cos of all of the slippery rocks. She always did it fine on four legs but on three she gets nervous and wants to lay down. 

Thank you guys all so much now I know not to give up on my boots! haha!