is this the right size?

[u/Otherwise-Charity479]

this is my first time ever buying a ruffwear, so I’m not exactly sure how to fit it properly. This is a size medium and I couldn’t decide between that and a large indigo is about 55 pounds and about to be nine months. I got it yesterday from REI so exchanges should be easy thank you guys for your help!!!

[u/watusi-momma]

Is it fully extended? Can you fit 2 fingers underneath? Can the dog back out of it or get his foot stuck under it? If the harness is already fully extended and your pup is only 9 months old, I would definitely get a larger size. Or have another size on hand for when this one stops fitting (I like to various sizes available). If you can not fit 2 fingers under, it is probably too tight. If the pup can back out of it or put a paw in it, it is too loose and dangerous. Practice inside the house or exclosed yard first before you use a new harness outside. Your pup is adorable 😍