To shut my dog in the garden for the day?

You need to hire the expensive sitter, you've already been irresponsible by missing his vaccinations, don't make another mistake by leaving him alone like that.

Seems fine to me. Not ideal but not harmful dog will be safe and well and you need your medical procedure.

Seems ok to me, my ddog hated kennels and fog sitters and was absolutely fine being left as you suggest, dogs vary and as long as they don’t have separation issues and are used to being left, they will be fine, needs must.

Kennels, even for a day, can be extremely stressful for dogs.
May or may not be the case that it's stressful for OPs dog, but in his own back garden with access to food, water and shade I'm sure he'll be fine. I would always choose my back garden over kennels and strangers for my dogs.

Dogs cannot tell the difference between 10 minutes and 10 hours. Once you've left him and he's assessed his situation, the overwhelming likelihood is he will nap most of the day.

It's a once off and this is important, he'll be fine for one day

Depends on the dog. My dog would be fine with this but she mostly hangs out outside anyway, has an outside kennel which she prefers in summer, and is very independent. If he's going to be going wild with anxiety of course it's cruel, if he'll just loaf around enjoying the sunshine it's fine. You know your dog better than Mumsnet so only you can really judge how he'll respond.

Good luck with your procedure 💐

After a horrible experience watching a woman in hysterics bringing her dead dog into the vet after he went outside and choked to death on a stone, no, I wouldn’t do this in any circumstances.

I don’t know about this. If it got into the wrong hands then it’s pretty much an admission of an empty house.
OP, is there a friend or neighbour who could help?

He'd probably be fine, but you just cant be sure, and I'd worry about theft or him getting out. Id go for the expensive sitter. Failing that, can the cinnamon trust help? Im sure they help with short term placements for owners who are elderly or ill.

Why will he go for 12hrs without a wee if he's going to be in the garden?

Confused.

Have you contacted the local kennels to explain and ask if there's an isolation kennel? My dog can't have one of the vaccines because of a medical condition so goes in the isolation kennel away from other dogs. I'd also contact your vet today to see if your dog can get the vaccines now to allow him to go in. That way you have peace of mind. The other things I'd try is asking on my local Facebook page if anyone could pop in (eg teenagers just finished their exams) for payment. I'd also see if your booked dog sitter would be willing to do it if you gave her a lift to your house and back that day, or you dropped the dog at hers and picked it up after.

Mine would be scratching at the door after 5 minutes! He’s normally a laidback chap but would be super confused in this situation and has separation anxiety.

I can’t imagine kennels being much cheaper than a dogsitter popping in though.

Mine would .dig the garden up or just bark at birds ! Then scratch at the door to get in

What will happen if there are any complications with the medical procedure and they need you to stay in hospital overnight?

My dog would go off his head with anxiety at this, but they’re all different. Good luck with your op.

Yes a dog walker will just put him back in the house for you. My dog walker also does "pop ins" for dogs just to make sure the dogs are OK, but it doesn't look like you want to pay.

One question - will you definitely be able to get back that night? Is there any chance the hospital could keep you in? Do you have a contingency plan? Otherwise I think the plan sounds reasonable but ideally I’d want someone to check in on the dog.

I would have to get the expensive sitter, it is just too long to leave a dog alone in the garden. But I would ask my neighbours first to help.

If he is normally okay to be left in the house for shorter periods, I think I'd just try and book a dogwalker to take him out in the middle of the day rather than trying to get a dog sitter for the whole day. Mine would prefer this because it would be closer to his normal routine, whereas he'd be confused to be left in the garden all day if it had never happened before.

When is your appointment can't you get him his booster and organise kennels i know mine will take them if they have had a booster within 2 weeks of boarding.

He will be absolutely fine.
His needs are met and he'll probably just nap most of the day.

Do you have neighbours you can ask for help?
I'd rather my neighbour ask me to pop in than you leave him outside.

I get you are in a bind but pay for the more expensive sitter , or see if there is a dog day care that can take him and drop him home i think it is to long to leave a dog to mooch about the garden unsupervised all day.

You pay for the far too expensive dog sitter I'm afraid. Even if they come by for the afternoon.

You can't leave a dog for that long locked outside. What if there is a thunderstorm (common at the moment) or something we're to happen?