Ok... my girl has mass or something behind her right shoulder blade. It's maybe an inch by 4 or so inches. Size is really hard to determine, I can't really explain it. So on her left side you can feel the muscle a little, but this is different. I really questioned whether I was crazy or not, I tend to over react when something seems unusual in my dogs. Now it is larger and obviously different from the other side. I feel like when she is standing up, particularly when she is walking, it can be seen. She is with me constantly and I am usually upstairs so she goes up and down multiple times during the day and she is slower going up the stairs and hesitates jumping on the bed. Recently she has lost her footing and kind of slid down the stairs sprawled out, she has done this twice. I walk beside her now and remind her to go slow. She runs when she sees a rabbit or squirrel though! I know she needs to go to the vet and I plan on doing it ASAP. I just want to have some idea what is going on with her... she is a very scared dog and HATES the vet.

Oh! She is 4 years old, around 70-75 lbs, pit/shepard? Mix

Honestly, there is no way we can say what it is.

It could be anything from an injury that has not healed properly to a tumor.

It definitely needs to be seen to by a vet very soon.
She may require surgery to remove it if it is a tumor and a biopsy done.
If it is muscle damage then your vet would have to instruct you as to the best coarse of action. (surgery, rest or medication)

I know no one is going to be able to diagnois her, just looking for some ideas of what it could be. We are going to the vet very soon... I just pray it's nothing serious, not only because I would be devastated but also that she has been my healthy dog. My oldest had a hip replacement 2 years ago and the youngest is allergic to EVERYTHING, it's been nice to have at least one with no medical problems!

It scares me to death!

It's awful, dogs are just like kids. You never want anything bad to happen to them.

I hope it is nothing serious, I will keep my fingers crossed for you.

Please come back and keep us updated :)