Hi, I know there's been a similar topic very recently on escalating grumpiness/aggression - I've read Danni and Freya's thread with interest, and found the links very useful - but I'm wondering why Bella has changed so much since her spay, and am hoping for some advice from you wish COLers about how to handle this.
Bella is 19 months old, and was spayed at the beginning of May, which seems to have gone fine. I didn't walk her for ten days afterwards, then eased her back into it. For a while we didn't meet any dogs who really wanted a good sniff, and she warned off those who wanted more than a cursory sniff. Then a couple of weeks ago we met a four month old flatcoat, who approached very boisterously. Bella greeted him ok, but then he bowled her over and she yelped loudly, then snapped at him. He didn't take the hint at all and she told him off thoroughly; lots of noise and snapping, but didn't bite him. The owner pulled him off, and we were then joined by an old English sheepdog, who started playing boisterously with the pup. Bella pressed herself behind my legs and barked/snarled if they got too close. I moved off with her pretty quickly, and felt that her behaviour had been understandable and appropriate, considering she must have still been tender, and the pup seemed to have hurt her.
Since then though, any dog sniffing or approaching her rear end gets snarled and snapped at. On Monday, a Finnish Lapphund was rather persistent, and Bella snapped at her. The other bitch went straight back, and there was lots of snapping and snarling and physical contact. The owner pulled their bitch off. I would have moved on, but the owner kept chatting and apologising, and the lapphund approach Bella again, despite me trying to block the contact. Same thing happened again (Bella snapped, and the other bitch retaliated) and this time the owner pulled the dog off and hit her repeatedly.

I moved on as quickly as possible, having pointed out that Bella had snapped first.
Then Tuesday we met a couple of dogs who greeted briefly without bum sniffing, with no problems, and then met a young and very submissive jack russel bitch, who was very keen to greet and play. Bella greeted her politely and moved away, but the little bitch just kept coming back and back. I asked the owner to call the dog back, as mine isn't friendly at the moment, but he just said "She just wants to play"!

Bella, inevitably, snapped at her when she kept persisting, and I managed to scoop the dog up and returned her to her owner with a few choice words.

I rang the vets this morning, and described the situation to the veterinary nurse, asking if I should bring her in for a checkup. She said that it sounds like a behavioural issue rather than a physical one, but also to do with her hormones.
Just for background......
Bella is a tiny bitch and was quite submissive with other dogs as a puppy. Until this I'd been really proud of her manners with other dogs (I tried never to interfere with her doggy interactions) and she seemed to be very effective at using the right calming signals with other dogs, and greeting in a calm and polite way. She got less playful as she got older, but still did invite some dogs to play, almost always by play bowing and running round in circles, rather than jumping all over them.

She's always been scared of big fluffy dogs, after she was bitten (not badly) and dominated by a friend's akita malamute cross, but she would tend to scream and run rather than snap (though she would snap if cornered).
Bella had her first season in January (at 14/15 months), during which dogs and bitches showed a lot more interest (I kept her in in the middle, but in the very early and late stages), and she would sit down or move away, or tell off the more persistent ones. Bella then had a phantom pregnancy, during which the increased interest and her response continued as before. She had much less interest in playing and in dogs generally. She has shown a bit of possession aggression/resource guarding towards other dogs over her ball, or if she's on my lap.
So..... <deep breath....sorry for the essay!>

- Is this escalated level of aggression likely to be due to the flatcoat hurting her, combined with residual tenderness after her spay?
- How much are changed hormone levels following her spay likely to be affecting her?
- How much of this behaviour is just normal behaviour for a mature, spayed bitch, especially considering the very interesting "He just wants to say hi!" article linked to on Danni and Freya's thread?
- What do I do now?
Do I handle it proactively, as Hannah described with Normy; distracting her attention and rewarding? But what about when other dogs are persistent? - How can I re-socialise her to not view every dog as a potential threat? I'm really sad that she's always been so good with other dogs, and that now she's starting fights; I'm worried that she's going to get badly hurt.

Thank you so much for reading all this if you are still with me at this point!
