How often to stop on car journey

[Beansandcheesearegood]

Planning our holiday. We have an 18 month old springer spaniel. We have a 3.5 hour drive.
We will take him out before we go for a good off lead run for an hour. Hen leave another hour ad he drinks so much he will need to pee! We will stop 2 hours in for a break/ quick walk- 20 minutes max.then another 1.5 hours. Is this enough or do you think we should stop more? He'll be in the boot, enough space to move around etc and hoping he will sleep...

I stop every two hours with my dog for a short walk. Works for him. He can hold his bladder much longer than that but he needs a stretch at that point and will let me know he wants a break if I don't stop!

That's what I do. It's good for people to stop after two hours, too.

I did a 9.5 hour journey with my dog and stopped twice for toilet breaks/short walks at motorway services. She pretty much slept the whole journey, occasionally sitting up to look out of the window.
And I have just done a 3 hour journey with a 9 month old with no stops.
So personally, I would do the journey without stopping.

Same as SpanielsGalore above.

13 month old cockerpoo - did 3 hour journey no problem in the boot-crate. She had water and snack but just slept the whole time.

she only wakes up with the "goodbye" sound my Kia makes when the engine is turned off 🤣

If she is comfortable and has had exercise prior to leaving, then I'd say three hours give or take in one go is perfectly fine.

you know your own dog though.