My chihuahua had 2 puppies exactly a month ago and I have grown a little concerned this evening. Yesterday I picked up the tiny one of the litter like I usually do as they both love to be held and tummy rubbed and when I put him on his back in my had I noticed a little bit of bloody discharged. I did not think anything of it but then tonight my momma dog was cleaning him up and I checked on him and his entrance was bloody. He seems healthy he eats all the time he is not as active as his litter mate or as big but has never been over spunky he has always since day 1 been more laid back and he is not emaciated looking just the smaller of the 2 he has not been outside and my 2 dogs I have already have current vaccinations nothing seems sighfully wrong with him any ideas?

Take him to the vet and they'll do x-rays right away. It'll probably be something he shouldn't have eaten (wood spliters perhaps) or twisted bowels. If you don't have the money to get it checked out right away, wait to see if it passes, but if it gets worse or he gets lethargic, definitely go in! Nobody wants a sick adorable chihuahua!

I agree, get that pup to the vet immediately.

Have they been wormed yet?

Yes has the mother been treated for worms and fleas?
I think it's best to visit a vet. Blood in the stool can mean many things, and why take the chance with such a young pup.
Have the mom and other pups been in for a once over since the birth?