Behaviour of female in heat

Hi Guys

I need some help! My Sasha went on heat last week Thursday unexpectedly and we took her the next day to be spayed as we did not have any plans of breeding with her so she got sterilised on Friday.


She has been doing well the whole time but not too fond of it when her brother comes too close which we understood but Tuesday night out of the blue the two of them started fighting over a ball which they have never done before , my male scratched her ear open with his tooth and she was bleeding ,after that she has been quite aggressive towards him ,she has gotten more jealous than she used to be and I am terrified because I don't want them to fight.

My question is , why has her behaviour changed so drastically? I have read that females tend to become a little more aggressive while in heat but I am scared that after this she might just stay aggressive?
I separate them when we are not home to avoid any problems and she cant wait to see her brother when we get home but not long after she gets all aggro with him. I am also scared that his personality might change because of this he is so calm all the time and usually never gets bothered but since she is like this he also does not stand back

What do I do? 

Not much help as I have never had girlies, someone will be along shortly though. I have moved this to appropriate section as you will get more replies  

Thank you so much!

He hormones are probably all over the place, coming into season, then being spayed straight away (I am suprised the vets did that to be homest as I had to wait 10 weeks after daisy's finished to get her spayed) That could account for her being snappy, he's probably sore and a bit sorry for herself. Just keep a close eye on them and hopefully they'll be back to normal soon

Firstly, like sazzle, I'm surprised that your vet spayed her! Secondly, she is, in my opinion, too young to be spayed, although it's too late now.

Early spaying can cause aggression, especially in bitches.

All you can do is watch them like a hawk until she's completely over her operation, and then hope for the best. At the moment she'll still be quite sore, so will have a shorter temper.

Thank you for your responses , spaying while she is on heat was not something we wanted at all but we did not want to take the risk of something happening , I tried putting the doggy nappies on her but either she or Klaus got them off every time and we did not want to separate them the whole time as she gets extreme anxiety when she is on her own.I will keep an eye on her , she seemed a lot better last night so we'll see how she goes on:)