This is her 4th litter - no real problems with any of the other litters

Fourth litter! OMG! No good breeder that I know breeds their dogs more then twice. Even then, there's a 2 year lull in between breeding. You dog is on her 4th litter at 6 years of age? That's just shocking.

Your question requires only common sense. Your dog has been pushing for 2 hours to no avail. Go to the vet! If you don't, you risk not only losing the puppies, but your dog as well.

After this litter, do your dog a favor and stop using her as a breeding machine. Get her spayed. She's had enough pregnancies.

EMERGENCY VET... NOW!

Pushing for 2 hours is NOT a good sign!
There may be a puppy stuck or other complications. If the b*tch is in distress you need to take her in immediately.

2 hours of pushing or 2 hours between puppies requires immediate care.

I also have to be harsh and ask what you are doing breeding a dog 4 times when you still don't know what you are doing? I hope by now you are already at the vet.

ERROR: You must spread some Reputation around before giving it to shazamataz again.

I really do hope the OP is at the vet as we type.

It's just shocking that this poor dog has been bred 4 times when the owner obviously has no idea what he/she is doing.

When will backyard breeders be stopped? Four litters, which is way too many, and the dog is only 6 years old. Her poor body has probably just had enough.

By the ANKC rules here a b*tch must not be bred before 12 months of age, may not be bred on consecutive seasons and must not be bred more than twice in an 18 month period.

So if you do the math...

Even if you did breed at 12 months (which no good breeder will do)

B*tch mated at 12 months.
Litter arrives at 14 months.
Next season at 20 months - skipped
Next season at 27 months - mated.
Litter arrives at 29 months.
Next season at 35 months - skipped
Next season at 42 months - mated.
Litter arrives at 44 months.
Next season at 50 months - skipped
Next season at 57 months - mated
Litter arrives 58 months.

Total adds up to a 6 year old dog.

This poor girl has been bred on every second season her entire life... and that's providing she had regular seasons every 6 months on the dot.

Here, no legit breeder breeds a b*tch more then twice in her lifetime. There may be an accidental 3rd litter, but it's not done on purpose.

Once they've had two litters, they're retired, spayed, and either kept as a family pet, or adopted out.

Eh.. Welcome to the USA! Its not unheard of at all.. I wish our kennel club would set some rules like that... It would make a lot of backyard breeders with fancy kennels upset.

My bloodhound lady built another kennel :(