Puppy diahhrea

Question
I adopted a collie/lab 5 days ago from a rescue society.  He was given his first shot by them, the sticker says DA2PPv.  Since I brought him home he has had diarrhea.  Some are mushy like pudding and some are more runny, sometimes with a mucus like substance in it.  Yesterday, I noticed small amounts of blood in 2 of his poops.  He is going about every two hours and sometimes is straining after he goes the first time and nothing comes out.  He has thrown up about 3 or 4 times since I've had him and it's foul smelling.  He is on Science Diet puppy food (hard food)and eating regularly, he also drinks plenty of water. He has gotten into the cat food (whiskas hard) a few times.  The only other thing I have given him is a bacon flavored chewy bone from the pet store.  When he's awake, he's very playful and alert, he loves to play with the family and his toys.  He's about 4 months.  For example, I went to be at 11:00pm last night and laid clean puppy training pads down.  I got up at 6:00am this morning and there was 6 poops (like pudding, no blood) and 1 throw up (foul smelling).  Does this sound like he needs a trip to the vet?  I've been searching the Internet for answers but I am really getting mixed reviews, some say take him some say don't.  Your thoughts would be greatly appreciated.

Answer
It doesn't sound like he has parvo because of the color and consistency of the stool but the reason you need to get him into the vet's is to get a stool sample checked for coccidia which is a protozoa, not a worm, and to get him looked over for worms, started on heartworm prevention and have him examined all over.

You have him on the best food there is, and the fact that he still has diarrhea tells me that aside from the usual stress of being relocated and adopted, he has to have some sort of worm burden. And a heavy one at that. Another problem he could have is a mal-absorption problem and the vet would have to determine that by looking at his stool and his general all-over condition. It is rather common in collies but mixes not so much.
It is very common and the sooner you get him in there the better.
I hope you get this resolved quickly for both of your sake. Please let me know what you do find out.