littermate play

Question
Hi Kim, My two 7 month old female standards love to wrestle.  They wrestle frequently.  While wrestling, they snarl, bare their teeth and sink their teeth into each others flesh.  It is easy to separate them and calm them.  They begin each wrestling match with a bow (you know how dogs lower their front and raise their behinds) and a wag.  They end each wrestle match with a wag and they walk off together or lie down together for a rest.  My question is will these seemingly vicious wrestling matches escalate and become truly vicious.  Am I allowing something to evolve between them that I should be nipping in the bud?  Will they eventually mellow out?  Are they attempting to establish their places in the hierarchy?  Or are they simply playing the way puppies play?
I would like to add that we spend a lot of time with lots of other dogs and my puppies never initiate this kind of play with other dogs.  There is one other dog that initiates this kind of play with my puppies and my puppies are more than happy to oblige.  They really seem to love this type of play.  I just want to make sure I'm truly observing play and not something potentially very bad.  Thanks so much for your expertise.  

Answer
Hello Kim,
Your question is a good one and I am asked that on occasion.  The answer is that your girls are sharing the bond of sisters and are happily playing with the buddy they grew up with.  I have 2 brothers that were littermates (and also their father and uncle) in the house together and they love to play that way, then fall asleep the way they fell.  Every once in awhile they get over-excited or one might nip the others ear a bit harder than it meant too and they might have a scuffle, but those are bounderies that they have to deal with on their own and I only step in if one or the other is getting hurt (which is very rare).
For now I would let them play as much as they want as long as its good clean fun.  If there is a bit of an arguement, let them work it out, and they will soon be friends again.  
Do be sure that YOU are the ulimate BOSS in the household though.  What you say goes and both of them need to know that.  
Its good to play with them together, but also nice to spend quality one-on-one time with each of them.  This brings out each individual character in each dog.  You might want to think about enrolling them in Obedience/Agility classes.  Poodles excel at both Obedience and Agility because they can work their brains and Poodles are very smart.  Its also really fun for the owners.  

Well, I hope this helps you some.  If you have other questions/concerns/comments about this or other questions in general, please feel free to ask.

Thanks for using AllExperts.com,
Kim