Get Your Dog Care Questions Answered by Experts ASAP
How old is your dog?
How long has this been going on?
Has he had anything similar to this in the past?
Any medication history?
Does he or has he taken asprin or ibuprofen?
Actually, the aleve can cause digested blood to appear in his vomit and in his stools. It causes stomach and intestinal irritation, ulcers, and bleeding. I suspect the vomiting and the diarrhea are the result of the aleve and he may have had some prior issues with ulcers that you were not aware but the aleve irritated them again. I hate to say it but I do suggest getting your guy into the vet for some bloodwork. Aleve (naproxen) has been known to cause the symptoms I have mentioned as well as kidney issues because dogs just do not tolerate this very well.
I am somewhat suspicous that he could have an abdominal mass that is complicating things here. It would be in hist best interest to have an abdominal xray or ultrasound performed. I suggest that you take his temperature to see if he is running a fever or actually too cold due to illness.
The sooner you can get him into the vet the better.