My great dane is giving birth, first puppy was born like 5 hours ago, we made an ultra sound so we can know how many puppies are they, apparently she's having 4, so how long does it take to give birth for the other puppy ? Is it normal ?

I would call the Vet and ask. You didn't get any guidance from the Vet?

Here's a good site - Pregnancy Guide Prenatal Care, Breeding your dog (http://www.dogbreedinfo.com/breedingpregnancyguide.htm)

You've asked about this dog as well as your two mastiffs before. Here's what "Lucky" said about the Great Dane and the pregnancy:

"The size of any litter can vary, it just depends on how fertile both male and female are and how many times she's been bred.

You should become close friends with your vet... You can have an ultrasound done any time now and get a good estimate. Around 43 days, Xrays should be taken to count skulls and spines and to see if the puppies can pass through the birth canal.

Dogs pregnancies are about 60-63 days. Purchase books on what to do and how to set up a welping pen.

I also hope that you have about $2000 stashed away for any emergency. Large breed dogs are not known to have difficult births, but it does happen and emergency c-sections should be added into this ordeal."

Why are you on the Internet and not on the telephone with the Vet?

Brace yourself here - you have consistently ignored advice you have requested, opening new threads when you didn't like the first set of answers. https://www.askmehelpdesk.com/dogs/neapolitan-mastiff-hot-weather-669156.html

If you intend to continue breeding your dog, despite the risks to her and the puppies, and continue to ignore any/all advice you are an irresponsible pet owner.