I have a 6 year old mixed mutt, she is a female and she is spayed. About ten minutes ago she peed in my room (she never does this). It wasn't much, i would say maybe a small cookie size amount but i was very alarmed when i looked at it. It was just red blood. I went downstairs to get something to clean it up with then i saw a large amount of pee mixed with blood on the bottom stair case. In that pee there was tissue like red discharge in the blood. I am very scared and i am going to take her to the vet asap but does anyone have any idea what this might be? She is over weight because my dad feeds her constantly, might this have something to do with it? God this sucks, i just hope she will be okay and it's nothing to serious. I'm freaking out here guys!! Any feedback would be great. Btw i just got a small new kitty, i don't know if that makes any difference.