Dominance and snapping?

Lacey has just gone on 6 1/2 months, which I have been told can be a little bit of a tricky stage. She has started to get very dominant with our 7 year old, Tyson. Tyson has been so tolerant with Lacey which is great, but now she is at the stage where she is already slightly bigger and wants to be in charge. She gets very nasty towards Tyson (especially when there are people around) to the point where I can see he is about to snap. He has snapped back twice and I have watched what has happened and neither of them seem to back down at all and it turns into a full on fight until completely separated. Yesterday when Lacey was going at Tyson again my partner went to calmly separate them and Lacey growled and bit his hand (not hard but she definitely wasn't playing). It worries me as I've never seen her like this and I'm not really sure how to go about dealing with it.

Two dominant dogs can be a nightmare. Firstly are both entire?

It definitely has been a bit stressful! Both are desexed (Lacey only got spayed two weeks ago), which is why I didn't expect the dominance all of a sudden I think  

Has the behaviour only changed since the spaying? If so, it could be because her hormones haven't yet settled. 6 months is really too young to spay because you've no idea of future temperament, but what's done is done.

What I'd advise is to step in before they get to the fighting stage. If you see either of the dogs getting stressed or bolshy, step in with a firm "No! Leave!" and seperate them, or distract them with a game or a bit of training.

It had started about a week before spaying. Which is now a big regret of mine doing it so early and listening to my vet who was adamant that it was best to do it asap. But like you said, what's done is done unfortunately. And yes we have been trying to separate before it gets out of hand and we usually get there in time which is good. I just hope they can find some sort of balance between them, like there was up until a few weeks ago.

When Lacey snaps, or starts to show signs, would it be a good idea to put them in separate rooms perhaps? I've no direct experiece of this so its just a suggestion. Maybe if you can distract Lacey from that frame of mind with a puppy kong or something, that might help re-direct her agression into something more constructive and fun. It does sound like she's trying to become 'pack-leader' - perhaps she's pushing Tyson to see what she can get away with?

I have been separating them when she starts getting nasty, but sometimes I think it seems to make her want to get to him even more. I think distracting her would be a good idea to try as it may be able to prevent having to separate them all the time and make it less of a "big deal" to Lacey. I will try it out today and let you know, thanks!