I have two bitches Josie who is 7, Suki (her pup)who is 2.  Josie was never aggressive to dogs until she had her pups.  The first time we took Suki out in the town to socialise her, Josie went mad, barking at any dog that went near her.  So we then walked Suki in the town by herself.
From then on if Josie was on a lead, and only when on a lead, she would do what I call her horrible bark, snappy barking, but never making contact, at dogs when they went past (this has been much better since I started using a halti).  Off the lead she has always been fine, apart from occasionally if a small dog on a lead starts barking, she would go in and bark back, but no contact. Because of this, if I can't see round a bend or if I see a small dog on the lead coming I put her on the lead.
Today we were out on a walk with the family, I was talking to someone, dogs were off the lead, OH was a head with the dogs, Josie shot off and pinned a small dog to the ground with her mouth round it's back.  OH got her off straight away and moved away with her.  I didn't see what happened, but I still can't believe she made contact with the dog.  I went after the couple with the dog apologised as much as I could.  They were actually lovely, and could see I was as shocked as them.  The dog was fine no broken skin or anything, but probably scared stiff.
We also have a holiday cottage next to us, Josie never used to bother with the dogs that come on holiday, but since having Suki, she now does her horrible bark at them, sometimes, and then ignores them if she meets the again.  
I usually walk the dogs, have eyes in the back of my head, my other half is much more relaxed!
Another thing, Josie is a joy, if Suki isn't there.  I can take her to the park, and she is totally focused on me, not bothered by dogs at all, when she is on or off the lead.
So my problem is now that I can't trust her anymore.  I can't let her meet the dogs in the holiday cottage and will have to have her on the lead permanently, unless I can see way ahead, in case she goes for a dog again.
Has anyone got any tips for making life easier? 
We were also considering getting Josie spayed next month, as she suffers from phantoms.  Could this help with aggression?  Our friends had their dog spayed and it really calmed her down. 
Also OH thinks Josie may make Suki aggressive, although she has a fantastic temperament, I'm not sure.
I'm so upset.
Sam

If she suffers with phantoms then her hormones are more than likely all over the place, so spaying may well calm things down, but i would do it before this becomes a learned behaviour as it will take careful training as well.

It may well help or it could make matters worse and some bitches will become more aggressive when the female hormones are reduced.

Think it best that your take this aggression as a separate problem and if you wish to spay because of the phantom problem then you should go ahead as it will undoubtedly help with that and deal with the aggression in another way if necessary.

my bitch had terrible phantoms and can be agressive,dominant and did a lot of scent marking. since being spayed i have noticed no difference whatsoever- i was worried she would be more agressive but she is no worse than before.

> Another thing, Josie is a joy, if Suki isn't there.  I can take her to the park, and she is totally focused on me, not bothered by dogs at all, when she is on or off the lead.
>

This is the part of your thread that caught my attention, I wonder if Josie still feels that she still has to protect her pup, and maybe this could be compounded by the erratic hormones. I also think maybe the aggression thing needs to be sorted first, I understand that spaying can sometimes take away some of a bitches sweeter nature , but don't quote me on that, it's only what I've heard, it didn't actually affect my three girls.

As your OH is more relaxed when walking the girls does Josie behave in the same way when she's with him? Somehow she needs to learn that the dogs that you meet are not a threat.

Hi Nicola,
Josie does act the same with my OH.  When I say relaxed, I mean as in the surroundings, dogs, people, he doesn't anticipate situations as I do!  I walk them everyday, am very relaxed, because I feel in control, I'm aware of what is going on around us.  Have Josie on a lead if I don't know what is round the corner.  Also her recall is very good, so if there's something in the distance, she is very good at coming back.  Unlike Suki actually who isn't as good and can go off full steam ahead, to say a hello.
i'm sure she is trying to protect Suki, or she would do it when she is by herself.  At the weekend, I was in the park with just Josie, on the lead and 3 whippets and a lab came storming accross barking.  She totally ignored them, I could see them coming, had a treat in my hand and she just carried on walking to heal.
We were going to get her spayed, because of her phantoms and also, after the last couple of seasons, for about 3 months after her season she would just be very down.  This time (had season end July) she did have a phantom, but has not been down, she's been a very happy girl and she's so loving, she's wonderful in the house.
I don't know what to do!

Hi Sam-jo,

Sorry to hear how things are going with your girl. It reminds me of my own male I walked him around no lead completely cool & friendly with everyone, then after I studded him he became highly macho with other male dogs. Total aggression that nearly ended his life that really upset me. I' wondered where my nice dog had gone.

If your thinking about spaying her I would maybe hold fire and talk to a vet about referring you to a good dog trainer, she is being over protective and what your going to have to do is re train her not too be so OTT. Muzzle her and do not let her off lead [a 16 foot flexi will let her get a little way from you]. Watch her body language when you see another dog approaching my snoop had good days then bad, call her pup Suki first get her to sit give a lovely treat and I expect Josie will come back too and when both sitting tell them to leave when the dog goes past. It will take time it took my dog & me about 6 months. So worth it now- no more crying walking home with a demented animal being horrible to other dogs. :-)

Thanks for the replies, I am going to talk to my vet, see what he says.
I've been walking Josie on a double lead, attached to halti head collar and harness, which is no problem, she walks well to heal.  We haven't met any dogs yet, unfortunately (or fortunately, because it's less hassle!) we are fairly remote so don't normally meet dogs on our local walks.  That's why we go into the park in town once a week.
Has anyone else noticed a temperament change after spaying?

I've noticed with my Sheltie that she is more vocal (yap yap yap) and maybe a bit braver than she used to be, but that could be of course because she's older, the most noticable thing for me is her coat, very heavy around the mane and trouser department.