Some advice

My mom and my little sister (she's 15) have a puppy they brought home from the shelter, apparently a terrier/lab mix, real cutie. My sister came home from school today and noticed that there were blood stains on the doggy's newspaper (she's paper trained). The dog appears to be healthy and jumpy other than that. It is a female and she is spayed. I was wondering if I could get some advice or info on what it could be - my mom is at work and already looking into taking the dog (named "Oreo") to the vet today or tomorrow first thing, so that's not a question, but my sister was nervous as to what to do in the meantime, specially since the puppy wants to play and romp and doesn't seem "sick" at all.

Just watch to make sure it does not get worse it could be from the surgery to spay. But definitely go to the vet with her.

Blood is never good, so I would agree, keep her as quiet as possible (I know, its a pup full of energy, just do what you can) and look for anything else that might be off so you can report it to the vet.

let us know!

It could be bladder stones too.. Boo passed one a while back and peed blood. Otherwise, it could also be a very bad urinary tract infection. Definitely needs a vet visit (in the meantime, be sure the dog is still able to pee, and if not, head to an emergency vet).