I love dogs and I live in Wassenaar.
I volunteer every Wednesday afternoon as dog walker by the animal shelter Dierentehuis Stevenshage in Leiden (and I can recommend it for a longer stay during your holidays). I can drive to your place and visit your dog by your house, and have a walk to his/her favorite park. Just sitting in the garden is also fine of course. I'm used to both energetic young dogs, and senior quiet ones.
Contact me for any additional information!
I would be happy to meet you and your dog, and see if we can have a great time together!