I had a problem with my 22-pound Jack Russell Terrier beating up on my (at the time) 2-pound Chihuahua puppy when I first brought him home. She wasn't trying to hurt him (she just wanted to play!) but, being so much larger than him, she would hold him down or push him over too roughly. After I trained her, she would only gently mouth him (most times she wouldn't even touch him with her mouth), paw at him gently, or chase him around the room. They still had tons of fun and I didn't have to worry about him getting hurt anymore!
Here's what I did:
Every single time the dogs were together, they were supervised. If I couldn't be there to supervise the dogs, then they were kept in separate rooms or crated.
I created a warning word. (I chose the word "Gentle.") I never yelled it, but I said it as a reminder whenever the play got too rough. If the JRT didn't mind the warning word, I got up and gently removed her from the room for a few minutes (at most 5 minutes). My JRT never fusses outside the door to be let in, but if she had, I would have waited for her to be quiet and calm before letting her back into the room.
I like to use an actual barrier such as a solid door instead of a crate or a baby gate. First of all, a crate should never be used for punishment. It's a den and a place of comfort and protection--not a timeout place. Second, the idea is to socially isolate the dog for a few minutes. This concept is called "negative punishment"--taking away something good that the dog likes in order to punish them, such as taking away a toy when a dog is aggressively guarding it, or moving a dog off of your lap if they are barking at strangers. They learn that in order to keep the thing that they like (ex. a toy, access to playtime, attention from people, sitting in someone's lap, etc.) that they must obey the rules. It may sound harsh, but these kinds of boundaries are really important and quite natural.
Essentially, the idea is to teach "bite inhibition." Puppies learn this concept from their mother and littermates. Littermates will often wander away and completely ignore a puppy that is playing too roughly, leaving the offender to find out the hard way that other dogs don't like to be mauled during play. The idea is to communicate that playtime stops when it gets too rough. Your girls may not be assertive enough to uphold the rules themselves, so it's your job to show them that you can reliably protect them from bullying.
Your male may not be intentionally doing it to be mean. He may be doing it because he knows you'll scold him or pay him more attention (even if it's negative attention) whenever he misbehaves. As a rescue, this is a possibility. Therefore, to cure this potential problem, don't mind them when they're playing other than to silently observe and utter the warning word (ex "Gentle") whenever play starts getting rough. It's a one-strike-and-you're-out system. You see the play starting to ramp up and acknowledge all the precursors of your male that say he's about to start biting their legs, and you give the warning phrase. If he starts to bite their legs and stress the girls, you say NOTHING, get up, pick him up, and place him outside the room for a few minutes. Then you let him back inside and repeat the process. Be cool and collected--this is not to be mean and it shouldn't be done with an air of "Bad dog, you go outside!" The message should be, "Whoops, you broke the rules! Guess you lose your reward for a few minutes."
If you notice that he's playing really gently, don't be afraid to treat him. Sometimes I think people are afraid to interrupt good behavior by giving treats. But you can say "[name], good!" and hand him a treat. He may become suddenly more interested in you and stop playing, but the next time he does it, he'll go back to playtime faster and faster each time, and gradually he'll make the association that playing gently is what gets him positive attention and treats.
Also, don't be afraid to stress him. Trust me, it's better to stress him as a puppy than as an adult. Do you remember being stressed as a toddler when your parents taught you to sleep in your own bed? Similarly, your pup needs to learn boundaries, and it may not be pleasant, but it's for his own mental welfare in the end. The point of this exercise is actually to REDUCE stress in his life by teaching him what actions are socially acceptable and which ones aren't, instead of him having to randomly guess and potentially get it wrong.
This is an every day thing with him and he's stressing the girls and me out with it. :banghead: He's a rescue and didn't have a very good beginning so I don't want to stress him either, but I really don't know what to do to make him quit. I never had this problem with all my other chis I've had in the past.:dontknow:
