We have 4 newborn pups they are boxers we have a hundred watt bulb in the dog house for heat what could it be

It's winter and they are probably not warm enough bring them inside

You really should have them inside so you can make sure the mother is taking proper care of the pup feeding etc.

A HUNDRED WATT BULB?
They are freezing to death. SIGH

Puppies under 2 weeks of age cannot maintain their own body temperature which is why you need to keep the whelping box warm.

When you say 100w bulb do you mean an actual heat lamp, or just a regular bulb? They really need a heat lamp if it is winter where you are now and the temperature inside the box needs to be monitored carefully.

If they are outside in a kennel please bring them inside so you can monitor them overnight as well as during the day.

I so want to be on my soap box about not owning animals if you don't know how to care for them, or find out long before puppies are born how to care for them.

What type of bedding do you have. Is the "lamp" fitted to a temp switch to control the temp in the dog house.

Has some already died ? If so have you taken the others to the vet to be checked ?

I think it is the cold just make sure take them inside and put them in a warm room witthe mother.