Blood in urine

My 4 year-old Shih Tzu had bladder stones in July 2007.  She had surgery and had them removed and had urine tests once monthly.  She was on a prescription diet for a while, but in January, her vet said everything looked good, and we could resume regular diet.  She had another urinalysis in March, and everything again was normal.  Today, she was sitting on my bed and when she got up I noticed blood where she was sitting.  I haven't seen it in her urine yet.  What could this be?  Could it be bladder stones again?  I don't know if I can afford that surgery again!

[Aleda M Cheng, D.V.M., C.V.A]

Blood from the perianal area, or urethral area can be from infected or ruptured anal glands, vaginal infection as well as urinary tract infection.

Bring her to the vet for an exam.  If the anal glands are not infected have a urinalysis performed.  

The most accurate way to obtain urine is by cystocentesis (obtained by syringe directly from the bladder).  This way urine collection by-passes the vagina and skin.   If there are crystals in the urine, they may just be secondary to a urinary tract infection.  Crystals are small and they will pass on their own.  If there is any doubt your dog must have her bladder X-Rayed.  Not all stones must be surgically removed.  Small stones may pass on their own, but until they pass she have have to be treated a few times for urinary tract infections.  So just keep treating, and place her back on the prescription diet, if necessary.