Our dog is now 12 and is giving us quite a lot of trouble. She's had some urinary incontinence, although that's now under control, she sometimes wakes us in the night, she's can't jump into the car anymore, she's a bit sore and stiff in the mornings, she's very needy in terms of cuddles and our vet's bills have been expensive. She's on a special diet, which is more expensive. We can't leave her with anyone, so holidays etc., are looking a bit tricky.
We don't mind any of this because we love her and she's devoted her life to us. As she ages, we will make sure she's loved, comfortable and cared for.
My reason for posting is to highlight that dogs do get old and they will potentially cost you more at the vet's and will possibly restrict your lives.
It's just something else to think about if you're considering adding a dog to your family.