My mix breed puppy about 42 weeks old approximately 8.2 pounds. She has not eaten her regular dog food for about 1 week. Which she has ate regularly since she's been about 10 weeks old. However she still has an appetite for treats and begs for human food. So I cut down on her treats and I never give her human food, but no improvement so I then avoided giving her any treats yesterday and I saw a small shrinkage of food eaten probably about a 1/4 cup of food consumed but she usually will 4x that amount or more

Seeing as how she started picking at her food once you stopped with the treats, I think I would advise to cut out treats 100% and see what she does.

If she is bright, alert and active I doubt she is sick. I think she is wanting to eat dog treats rather than her meal.

Sometimes dog food companies will change an ingredient in their food. Some dogs are sensitive to these changes and will not eat their food. Maybe go to the store and purchase another bag of the same type of food you are feeding and see if she eats it.

You can also take the kibbles you are currently feeding and heat them up. Heating up the kibbles releases more oils and smells and picky eaters will sometimes like to eat that. Also try mixing in some canned food.

I'm assuming that you are correct on the age of 42wks.. She is no longer a puppy at this age, and being a small breed dog, dental issues can be a serious threat. When dogs get sore mouths, they stop wanting to eat hard food. They will prefer the softer foods, such as dog treats and canned food. It wouldn't hurt to make a trip to the vet to see if there is anything causing her to not want to eat hard food.

Another thing to consider.. small breeds simply do not eat a lot. Depending on the dominate breed and its standard weight, you might be over feeding your dog and she is just not hungry due to the fact you give her lots of treats throughout the day.

I'm a mean dog owner, my dogs don't get treats. They're just too high in fat and will literally spoil your dogs appetite to eat the nutritious food. Not to mention that 95% of the dogs that I work with who get lots of treats, are obese. And you do not want to deal with the health issues that accompany an obese dog.

But first things first... Take away all treats and just give her the dog food. Be sure to only give her this food two times a day as a meal instead of free feeding. This way you will know what she is eating or not eating. Keep it down for 30 minutes or so, than pick it up and repeat when its dinner time (or breakfast if she doesn't eat at night).