shitz zu bladder problem

Question
I have a Shitz Zu who is 12 years of age.
Some time ago (12 months) she was passing small stones in her urine,but these stones soon stopped and don't seem to have reoccurred.
However whilst out walking she is constantly crouching as if to wee but isn't actually weeing just leaving her sent. Also just recently and without any indication she has started to urinate in the house even though she has regular walks, this is totally out of character.
Before I consider taking her to the vet I would hope you could advise.
Thankyou David.

Answer
I would have to say that if she is no longer passing small stones then all that is left are the large ones which are causing her to feel the need to urinate and urinate in the house as well. Females are much less likely to wet on things to leave their scent and since she was having issues before I would get her in for xrays of her bladder. She only needs one stone in there to cause this problem- but it is one that is too big to pass.

You don't mention any food, treatment or medication for the previous stones so I would have to guess that this is what the problem is now.
Let me know what the xrays show.