I would first like to know if this dog has seen a vet recently and if you have gotten blood tests done. A change in behavior, especially one that seems this drastic, can be caused by imbalances in hormones. So I would suggest first getting blood work done and having the dog specifically get the thyroid checked. Barring any issues there I would like to ask a couple questions/say some things.
1. How do you train Rowen?
2. Do you leave Freya and Rowen home alone together when no one is there to watch them?
3. Did this behavior happen before you got Freya and you were in this new house? Could there be something in the environment around your house that could be getting her worked up? (Sometimes neighbors might have those silent bark things that sends out unpleasant sounds to get dogs to stop barking. Could something like that be happening?)
4. Pits are terriers and terriers have a very feisty personality. Pits are also prone to dog aggression (DA). I'm not saying she is DA though. It sounds like she is scared or anxious to me. Putting on a big aggressive display gets other dogs to back away from her. The whole idea of "look tough, act tough" and no one will bother you. As to why she is doing this, who knows.
5. I would stop taking her to the dog park. Dog parks are really not that great for a lot of reasons. They can be great when the dogs are trained to some extent and the owners are willing and able to remove their dogs and watch them. A lot of people just throw there dogs in there then just don't pay any attention which can lead to dogs picking fights, being a bully, etc. They are great when the owners are on the same page and are all committed to watching their dogs and moderate the play, but when they are not it can be disastrous. IF something were to happen and someone or some dog gets hurt, that dog is most likely going to be labeled dangerous and either gets put down or has to live the rest of its life with a muzzle per law.
There is counter conditioning techniques to use that focus on changing her emotional state when you have dogs approaching. These videos might help to explain more clearly too.
Behavioral Adjustment Training (BAT): http://www.youtube.com/watch?v=eMc-zyNfRO0
'Look At That' Game: http://www.youtube.com/watch?v=EdraNF2hcgA (Teaches the dog to see a trigger (in this case other dogs) and not react. Rather it becomes a game to look at another dog then look at handler for food reward. Now you have a dog who is willingly looking at other dogs and choosing to look back at you versus aggress).
Do you have any one on one time with Rowen without Freya?
Does Rowen appear more comfortable without Freya around? Does Rowen have an area that is "hers" where Freya isn't allowed?
Edit: I wouldn't allow her completely off leash unless she has a real solid recall either. I would also limit her interaction with smaller dogs for awhile. I'm not saying she will hurt them BUT if she did aggress towards a small dog, a small dog is more likely to be hurt due to their size. I don't trust my dog around small dogs at all. She is fine with them mostly but she plays rough and even rough play can hurt/scare/even kill a smaller dog so I just prevent it.
1. How do you train Rowen?
2. Do you leave Freya and Rowen home alone together when no one is there to watch them?
3. Did this behavior happen before you got Freya and you were in this new house? Could there be something in the environment around your house that could be getting her worked up? (Sometimes neighbors might have those silent bark things that sends out unpleasant sounds to get dogs to stop barking. Could something like that be happening?)
4. Pits are terriers and terriers have a very feisty personality. Pits are also prone to dog aggression (DA). I'm not saying she is DA though. It sounds like she is scared or anxious to me. Putting on a big aggressive display gets other dogs to back away from her. The whole idea of "look tough, act tough" and no one will bother you. As to why she is doing this, who knows.
5. I would stop taking her to the dog park. Dog parks are really not that great for a lot of reasons. They can be great when the dogs are trained to some extent and the owners are willing and able to remove their dogs and watch them. A lot of people just throw there dogs in there then just don't pay any attention which can lead to dogs picking fights, being a bully, etc. They are great when the owners are on the same page and are all committed to watching their dogs and moderate the play, but when they are not it can be disastrous. IF something were to happen and someone or some dog gets hurt, that dog is most likely going to be labeled dangerous and either gets put down or has to live the rest of its life with a muzzle per law.
There is counter conditioning techniques to use that focus on changing her emotional state when you have dogs approaching. These videos might help to explain more clearly too.
Behavioral Adjustment Training (BAT): http://www.youtube.com/watch?v=eMc-zyNfRO0
'Look At That' Game: http://www.youtube.com/watch?v=EdraNF2hcgA (Teaches the dog to see a trigger (in this case other dogs) and not react. Rather it becomes a game to look at another dog then look at handler for food reward. Now you have a dog who is willingly looking at other dogs and choosing to look back at you versus aggress).
Do you have any one on one time with Rowen without Freya?
Does Rowen appear more comfortable without Freya around? Does Rowen have an area that is "hers" where Freya isn't allowed?
Edit: I wouldn't allow her completely off leash unless she has a real solid recall either. I would also limit her interaction with smaller dogs for awhile. I'm not saying she will hurt them BUT if she did aggress towards a small dog, a small dog is more likely to be hurt due to their size. I don't trust my dog around small dogs at all. She is fine with them mostly but she plays rough and even rough play can hurt/scare/even kill a smaller dog so I just prevent it.