Boxer pup - malnourished?

Question
I recently purchased a puppy from a lady off Craigslist and think the poor little thing may be malnourished. When we went to pick the puppy up, I noticed that he looked a little skinny but didn't really pay it much attention until we got him home and I started to really look at him. She says the litter was born on January 11, which would make him 6 weeks old. I weighed him on Sunday and he weighs 6 3/4 lbs. I've done much googling but haven't really been able to find out much he should weigh at his age. Luckily, I came across your page and looking forward to your response. He has a vet appt on March 8th but I am desperate now. He is a really sweet pup and my heart goes out to him. Any feedback from you will be greatly appreciated. I currently have him on Blue Buffalo Freedom grain free puppy.

Answer
First, let me say that 6 weeks old is extremely too young to be taken from his mother and litter mates..........

Secondly, he needs to be de-wormed immediately. All pups are wormy. He can have worms that will feed off his nutrician, leaving him starved to death.

He must see a vet immediately. There must be other vets that will take walk-ins, especially on an emergency basis for a starving, sick puppy. Get him to the vet's immediately!

There are so many things that a young puppy can have wrong; worms, failure-to-thrive syndrome, etc.

If you want that pup to live and to be healthy- get him to a vet immediately.

He is way to young to be eating dry puppy food. Feed him wet puppy food. Also, he needs his mother's milk and now that's too late.

I suggest a homemade formula:

1 can evaporated milk (not condensed milk)
Mixed equally with water (bottled water- sterile)
Smudge of Kayro (white) syrup
1/2 cup plain, whole yogurt (no flavors)...

Mix in blender (might have to add water after mixing in blender due to volume)...

Seal and refrigerate. Feed at room temperature or slightly heated from a baby bottle or bowl.

Get him to a vet immediately!!!!!!!!!!!!!