Aibu for being unhappy my in-laws are putting a dog "first"

This.
It's the dog's home, find a creche that meets your requirements elsewhere.

Yes, he could and should. But he hasn’t. Presumably your MIL has been unable to force him to. But she clearly wants a relationship with her granddaughter, to the extent that she’s moving out of her home for a week to facilitate this. If the only issue is "she's putting the dog first!" that sounds ridiculous to me.

YANBU. I wouldn’t send her. I’d not trust the parents to keep the dog away from her.

What a reach

She isn't sending the child away. The child is having a holiday with grandma (or relative)

If it's massive, it's not a Staffie. Proper breed-standard Staffies are quite small dogs, albeit solid.

If you’re not comfortable with DD going away for a week then I wouldn’t have agreed to it in the first place tbh. So your husband wants a break and some peace, is he a SAHP? He could strop all he likes.
I wouldn’t send my child to a house with a feisty dog though. Where is MIL proposing to stay?

But the child is being kept away from the dog, as OP requested, so what’s the problem?

It’s not HIS home it’s HER home. He’s a 40 year old man who has rocked up with his big dog after splitting with his gf

With her grandmother

Where do you usually stay when you visit MIL as a family?

Do you trust MIL (and BIL) to ensure that DD doesn’t encounter BIL’s DoH? If not, then it’s unwise for DD to go. It’s just not worth the risk.

It doesn't make one iota of difference.

Either it is aggressive and should never, ever be anywhere near small children, or it is jumpy untrained and won't obey commands, in which case it should be kept away from small children anyway.

Whichever way, the OP is totally in the right here.

God forbid anyone asks a 40-year old man staying at his mum's place to take his dog elsewhere for week.

Yes, I agree with that. But your AIBU was about her putting the dog first. I can't see what else she can do.

But why? What would be your reason? You are just trying to pick a quarrel so you can avoid your DD having a visit with her grandmother. You’re not coming across well.

Mil comes to you for a week. I totally wouldn't want my dd near that dog and dd is used to dogs. Especially as you don't need childcare...I'll get them to drop this arrangement. Yanbu

" ... a giant dog, I think it's a Staffordshire bull terrier but it's massive. It's also untrained."
A Staffordshire Bull Terrier is very much a medium-size dog. If this dog is "massive" it's more likely to be an XL Bully, surely?

There is no way I would allow myself, never mind my child, to be around an untrained XL Bully. I'd even hesitate to be around an untrained Staffie (and I used to have a Staffie, I love them). Staffies are incredibly strong dogs, and can do serious damage to a human with very little effort on their part. Why has your brother-in-law not trained his dog?

Frankly, what it sounds like to me is that you don’t like the idea of your DD having a close relationship with your MIL at all. You are creating difficulties where there aren’t any.

Your MIL has done what you’ve asked and kept your DD apart from the dog. (Even though I'm not convinced by you saying the dog was being aggressive rather than playful/badly trained. Did it actually growl or try to bite anyone?)

What on earth is the problem of the two of them staying in a different relation's house? Does your DD actually care in the slightest which house it is? You are sounding sour.

Realistically, where can she send the dog? And can she really insist that it goes elsewhere when it is not her dog? It is her son's home too, by the sounds of it.

Well your MIL can't kick your BIL out for a week- it's his home. You've set a line, you don't want your child around this dog. So they are seeing your child elsewhere.

I don't get it. Unless this is some weird perceived hierarchy thing? You don't want your kid around the dog; your kid isn't around the dog- what's the problem???!

Everybody has their own agenda, don’t they. DH wants DD out of the house and getting stroppy if you even try to jeopardize that. BIL doesn’t want to find somewhere to put dog. MIL wants her DGD. FIL is doing his own thing. You’re the only one not getting what she “wants” ie peace of mind. Let’s hope DD is happy with this new relative.

I often used to find myself pushed around between people like this. My DM, almost 80, still is pushed around trying to be everything to everyone. It stopped for me when I started becoming as strident as everyone else was being towards me. It shocked me how quickly people gave in, or at least accommodated my preferences. All I had to do was ask.

I think you need to try and communicate with husband better over this somehow. You need him onside. If for instance you ever split up (I'm not saying over this specific issue), it sounds like he'd take your daughter there to be with dog and you wouldn't have a say so.

Dogs seem to be a very emotive subject on mumsnet in general.

I'm on the fence to be honest. Someone asked you if it was aggressive and you said it had jumped up on you but you felt it wasnt being playful - but that is how untrained and excited dogs act unfortunately - not necessarily aggressive dog behaviour but certainly uncomfortable for someone who doesn't like dogs.

I agree that jumping up is very bad dog manners and shows poor training by the owners. However it doesnt sound aggressive, you dont mention biting, growling, showing teeth, hackles up etc.

With your daughter being 7 now, I wonder how she feels about dogs in general and this dog in particular?

What was your husbands opinion of his child being scratched by this dog? Was he angry or was he of the opinion these things happen?

I personally wouldn't be happy with the annual 1 week trip in general with or without the dog and I wouldn't be happy about the dog situation either. It all sounds quite delicate and I think you should consider your next steps carefully. Hopefully you get some good advice or point of view on this thread.