*The doctor will need a sample of the urine for testing (at least 6 mL or 2 tsp). You can either collect a sample the morning of or the night before the appointment and place it in the refrigerator. Or we can walk your pet during the appointment and collect the sample after they go to the bathroom. For well behaved cats, if the doctor can feel the bladder in the abdomen, she may be able to get a sample directly with a small needle (cystocentesis).