1.Do you know how she injured it?
2.Will she let you do more than touch it? Will she let you squeeze with gentle but firm pressure, starting at each toe, and moving all the way up the leg?
3.Will she let you move each joint?
4.Does she cry at all, or jerk the leg away, when you do this?
5.Is she putting any weight at all on the leg?
6.Did you notice any swelling, or heat, when you were putting pressure up the leg?
1. My mom accidentally stepped on it
2. Yes, she lets me touch it with the pressure test that you suggested.
3. Yes she lets me move each joint.
4. No she does not cry out or jerk away.
5. She is only putting a little pressure...She was putting more on it earlier this evening, but then jumped off of the bed to go to the door...after that is when she started putting very little pressure on it and hesitates to do it at all...
6. No heat and I can't tell if there is any swelling, but it doesn't seem so
It is not sounding fractured to me.
Often if there is a fracture, there will be a significant amount of swelling.
Also, they usually do not put any weight at all on the limb. The walk on 3 legs only.
Shih Tzus are not very stoic in my experience. If something hurts they will let you know. Your girl may be different but I would expect her to at least cry if you came across the fractured spot.
I would make sure she does not walk around on it any more tonight. Keep her on a leash if that is what it will take to prevent her from running or jumping.
If she is not improved in the morning, you can have it x-rayed at that time. But it does not sound like an emergency visit is needed right now.
Of course if she becomes 3 legged limping and/or you notice a swollen spot, then she may need an x-ray sooner.