Dog vs Dog aggression

I have 3 dogs. All 3 were in a kennel I built that is about 50 ft by 100 ft. Well the youngest dog tore up my oldest dog about a year and a half ago. So I split the kennel in half.

The youngest dog is the puppy of my middle dog. Now the mother and puppy are fighting.This time its the mother dog attacking the puppy. The mother being about 6 yrs old and the puppy about 4 yrs old. All 3 dogs are fixed and all are female.

I can't split the kennel again. I have the puppy on a 50 ft leash attached to my deck till I can figure something out. I would put my oldest and the mother dog together but I don't want them to fight though they never have.

I'll try it tomorrow and keep an eye on them but I figured maybe someone has some advice. I'd hate to have to give one away.

opcorn:

what kind of dogs are these?

imo, you're going to have to split them up.

The dogs are as follows:

oldest - Chow/ mix looks more chow I think the mix maybe Shepherd,weighs about 70 lbs

mother - lab/chow mix looks like lab, people I adopted her from said she had border collie in her but she also has purple on her tongue,weighs about 70 lbs

puppy - lab/collie mix she is the biggest of the dogs, her dad was a huge lab. The collie hair on her looks to backup the claim of border collie in the mother.Weighs about 90 lbs

For now I have the Chow and mother dog in the same pen and the puppy in the Chows old pen.So far so good with the mother and Chow. They shared the pen for a couple of years without incident until the puppy attacked the chow and I seperated them. Figured keeping the pup and mom together would be better than the chow and mother.

I have a question about the pecking order. Even if I position myself as the alpha aren't the dogs still going to have a 2nd and 3rd in command and so forth? What is to stop them from fighting for position number 2?