Feeling mugged off but do I have the right to?

Good idea upthread about the puppy.
Say no to that and suggest the breeder (or whoever) keeps it another week.

I would not want to police grandchildren with a new (scared?) puppy (and clean up accidents)

If they are getting the puppy from a reputable breeder they will be able to delay picking it up for a week.

I think I’d compromise and say it’s more comfortable in your own home to care for them but it is going to affect your health to do so, so as there is still time - could they try and arrange an alternative

Too late now as you have already agreed.
I wouldn't have done it as know it's too much.
Obviously in an emergency I would.

Can you find a hotel/ guest house or something near them to save yourself 40 mins twice a day driving?

We have told our daughter we will help her out with her daughter if she brings her here.

Next time just say no I think.

IMO you should tell them that after thinking about this, you can have the children at your house if they bring and collect them but cannot look after a puppy.

It's irresponsible and unfair to get a puppy at the end of the school summer holidays when they'll both be returning to work and the puppy will be left alone for much of the day.

I would also tell them that this will be last time you can have the children for more than one day at a time so they can make other arrangements in the future.

No to the puppy !
What in earth were two teachers thinking of, putting a new puppy in the mix at the beginning of the school year ?

Let's hope they are being more proactive about the dog's wellbeing, going forward.
Otherwise, that will probably fall on you.

I can understand the 'there is nobody else', because that is our situation. My son and his partner both work shifts, so sometimes there is no option but for us to look after our grandson. However, in the OP's case, I think the parents are definitely taking the P, especially with the puppy being thrown into the mix too. Apart from the considerable extra work that would involved, it's also extremely unfair on the poor pup - in those early days, they really do need consistency and routine.

Is it just me that thinks they’re taking the piss?

No, it's unanimous.

The only way for you and your husband to help, if you both want to, is for the children to be brought to you each day.
The distance involved is of the parents' making so it's not your problem.

The puppy will need to be returned to the breeder for the week. It's too young for kennels as it won't be fully innoculated yet.

As a registered childminder myself, currently enjoying the busy summer holidays, I feel so sorry for you to have been put in this position by your inconsiderate son and daughter-in-law xx

We are always happy to look after our grandchildren, despite my chronic health issues.
Our compromise is that we look after the children in our own home, which is easier for me, as it has adaptations.

I think your family are quite selfish, giving no thought to your limitations. They would have known the return to school dates a year ago and should have thought it through.
As for getting a new puppy and absolving themselves of responsibility, that takes the biscuit!

It is a difficult situation for you, but they should look to getting a daily Nannie for the five days or getting them into a play scheme. Although those are probably full. The 6 year old might have a school friend who’s mum might oblige for the week as a favour to be returned, or small payment.
As for the puppy, as others have said, hard work, they don’t sleep all the time, but mess and chew, add to the mix small children, disaster!
Why are they getting a puppy when they are both out at work all day and have trouble looking after their children.
Who looks after the children during term time, before and after school?

It's absolute rubbish to say there is nobody else.
Have they never heard of childminders??

It's such a big thing to expect you to be on puppy duty, too.

They don't "hate to ask", because if they did, they wouldn't.

Your son and his wife will have known probably for a year that there will be a discrepancy between term times for them and their children and have taken your compliance entirely for granted. You are correct in thinking there is no one else available, the co-in-laws have wisely gone on holiday and child care for the young being organised months in advance and being notoriously expensive.
I feel you will probably agree, but this has to be the very last time and you must set limitations and conditions.
First: they deliver and collect the children to you, never mind how long how takes them; they will simply have to leave home and work earlier.
Secondly, there is to be no puppy. They have had the whole school holidays to train a new puppy (why have one when they will both be out at work all day) and they have left it to the end, expecting you to deal with an untrained young animal and leaving it with strangers for whole days. Absolutely not.
This pair have no concern for you and your health issues, expecting you to make a 50 mile round trip for 5 days, their children's welfare and their new pet. Their selfishness is breathtaking
You must face them down. Decide what child care you are prepared to do and where, and stick to it; your health is at risk. The fact they are so slapdash in their childcare arrangements does not bode well for their competence with their classes.

What’s happened to holiday clubs, day care etc I have never said no to any child care BUT I’m fairly fit it’s very different if you have your own quite major health problems
Two teachers will be bringing in enough to financially manage a few days clubs etc
A new puppy …forget it

25 miles is not that far. They need to bring the children to you daily. They must have made plans for the puppy long term (I assume they are not going to leave it alone every day) that plan can start early.

Have you always met your children's every wish? From the wording of your post, it does sound so. As a result you have selfish children who just expect you to do everything they ask of you, regardless of your health and welfare.

It seems that the in-laws have got the measure of them and go away on holiday or, I suspect, ar equite willing to say 'no'. Now it is your time to say 'no'.

You say in your post I said that we probably have no choice because there is no one else to have them. That is absolutely nonsense and totally illogical and the other in-laws had no difficulty turning them down and going away on holiday .

Arranging care for their children is your son and DiL's responsbility. They seem selfish and uncaring. To be getting a puppy and expecting you to look after that as well as the children, when they know you both have health problems, is frankly, taking the p*ss.

Tell them that you cannot manage to look after the children for a week, you might manage a day or two, but it would have to be in your own home. As for the dog, just make it absolutely clear that that is a no-no - ever.

I know it will be very difficult for you to say 'no' after years of responding to their every request and they will undoubtedly by horrified, outraged and angry, but it has to be done. You and your husband's health makes this essential.

You have agreed now to look after the children. The puppy is a no no.
Your son and daughter in law need to make other arrangements for the puppy, and yes they are piss takers. No thought for your health at all.

Why on earth are they getting a puppy?

Ridiculous.

I always find it difficult to say no when it comes to babysitting requests, and particularly the fact that you say they've no one else to help out, I know I'd reluctantly agree to it. However, considering your health issues, I'd make it quite clear that whilst you'll help out on this occasion, (due to the fact that the other in-laws are conveniently away on their jollies and unable to help), let them know that you're going to find 5 straight days a struggle. Ask them if there really is no other family or friends who could take the children for 1 or 2 days, or at least to give you a break for the odd afternoon?

If there really isn't anyone at all that can help out, as a grandparent, I would reluctantly agree to do it this time. But I would make it quite clear that in future they need to think further ahead and make sure that they have sufficient child care arrangements in place for times like this. Whether that's shared equally between the two sets of grandparents (assuming you don't mind the odd day), or paid child care. In future, they need to sort this out, as it's simply too much, and unfair, to ask of one set of grandparents to do it all.

However, the puppy would be a definite NO! I've had puppies myself, and they are bl***y hard work!! If it's not already housetrained, you'll be bending down on your hands and knees cleaning up wee and poo! I'd have to insist that they ask the breeder (or whoever they're getting it from) to keep it for an extra week! Incidentally, what on earth are they going to do with the puppy all day when they're back at work? Who's going to let it out then, and take care of its needs?! How irresponsible to take on a dog when they're both out at work all day!

The first no is the hardest and the puppy is definitely the last straw. Look after the health of both of you first

Sat no today, so they have time to make paid arrangements.

Why don't they do what my daughter and son in law do . The oldest 6.5 goes to various clubs that run during the summer holidays and 3.5 goes to nursery. Your son and daughter in law are teachers they can afford to do this to.

Please don't put your health at risk looking after young children is exhausting and for 5 days is going to set you back . Plus the children are going to get bored unless entertained over the 5 days.

I have looked after my grandsons in emergency either both together at their home if one or both of the boys are ill . Normally but at my bungalow I am disabled and have everything they need here including 3 boxes of toys and books . Plus they know nannies rules at her bungalow
which is 3 cupboards they are not allowed to go in which has my tablets and cleaning chemicals . I follow my daughter and son in law rules if they misbehaved, and they have to eat at the table and only allowed so much TV.

I have looked after when it's been planned but one at a time and usually just for the day. This year only had them singularly of the odd day. My daughter always asks well in advance and always asks if I am free that day. She never assumes. As 3 days a week I go to the same things . Monday Sit fit, Wednesday gel printing class and Thursday craft group.

If I want to take the boys out of lunch I always ask if it's ok my daughter tries to give me money but tell her it's my choice and my treat. I always bake with the boys they love it . They know how far I will tolerate things . And if I say nannie's not feeling well they adapt games to suit.

They always ask my son in laws parents well in advance as well . And they have a car with boys car seats they can put in the car. Once or twice a year they have the boys over night for special occasions. But like me they have house rules and follow rules set out their parents and they spent the night at their house not my daughters and son in laws .

At their house they have a down stairs loo which makes it easier for me. But I do go up to the boys rooms but they know I have to take my time and then sit down for a few minutes .

And they are taking the piss. They knew from the start of the school year they would be going back to work before your grandsons went to school had a whole year to plan. For your health say yes to a couple of days if you want to but not consecutive days and at your home . If they are funny about it tell them they had plenty of time to pre plan things . They know about your health and you needing to be at home .

My daughter if they come to see me always asks if I am free the boys play but know mommy and nannie like to chat. Also my daughter asks well in advance if I would like to go out with them . Which I always do.

This is just too much. 5 days in a row. I’d say yes to one day, then they’ll have to take a couple of days off work each or pay someone. The in laws chose the right week to go away! Tell them now so they’ve got a couple of weeks to sort it out.

You always have a choice - don't be a victim

"No, it doesn't work for us" is an option and the parents will find another solution

They will have to make alternative arrangements. The puppy would be the last straw. The children are one thing but a puppy ‘s needs are far, far more difficult. So the answer is that they have to find a friend or neighbour to help out or pay someone to take over. They are not thinking of you and your dh. They will have to put their hands in their pockets and pay. Can’t believe they are getting a puppy knowing full well the situation,

I think you both need to put your own health first and say no to this request/demand.

They must have known much earlier about the need for child care and should have arranged for alternative care.

I think you are being used and abused.