My Dog's Possible Cancer?

Hi all.  Just a question if anybody could help me.  Yesterday (Christmas Eve), my dog Sasha suddenly developed a problem urinating.  She's never had this problem before and it started about 5:00 p.m.  She was acting strange for the next couple of hours (wanting to urinate and squatting constantly) for the next two hours.  I took her to the emergency room and the doctor did an ultrasound and said she either has a very bad case of UTI or she has cancer.  He couldn't draw any urine out of her bladder because she was dry.  He explained the ultrasound and showed me the films.  He said because of the sudden onset and no symptoms prior to this he believes it's UTI.  I'm still going to have her tested for cancer because I have to know and see what treatment is available. 

Can someone recommend what type of tests would be the best in determining if she has cancer of the bladder?  I've had her since she was six weeks old and she is now a little over 14 years old and has become my "kid".  Needless to say this was devestating to me and nothing else has been on my mind since this.  She was diagnosed with inflammatory bowel disease last December by a specialist (of course this was after I went to my old vet who sent me to a specialist after she diagnosed her with brain cancer...hence old vet) so I'm a little skiddish on a vets diagnosis. 

 Any information would be greatly appreciated! 

HI,

My dog Spike, a 12 yr old Westie, was just diagnosed with bladder cancer last Friday. They  initially did treat it as a UTI for one round, and the meds  didn't work and then our vet  did an ultrasound where the mass was detected and put him on different antiabiotic . She also gave a test  for  bladder cancer/TCC which came back positive-I think its a blood test but not sure. We are now taking him to a specialist on Friday for a scope and biopsy as  the cancer may have already spread to the prostate. Yes , Spike started out with incontinence and straining, around Thanksgiving and now has blodd in his urine that is visible vs only detected in the urine analysis.  He is now on peroxicam , stomach meds and glucosomine. We take him out more often to pee and other than that he's acting normal, eating well, running around etc. Please be aware that a urinary tract infection also has the same symptoms , but an ultrasound did detect a mass so I'm sure your vet may do that just to rule out especially if the infection doesn't clear out, and maybe will do so anyone given your dogs age.  Good luck and let us know how you make out. Please knowt that we are all feeling your pain, you are not alone.

My Forrest received a definitive diagnosis after his ultrasound was abnormal, they biopsied his lymph nodes with a needle, which showed tcc. That was back in Sept. and he is still doing well with his medication regime, some days better than others with the straining, frequency etc. Good luck to you and your sweet pet. Karen