What do you do with your pets when you are traveling?

The reason I don't currently have a pet is because at this stage of my life I intend to do a lot of international travel and know it would be selfish and unfair to keep a pet.

When I was a child on occasion my family would go on holiday but only for a week at a time and my grandparents who doted on our dogs would look after them. My grandparent's spent a lot of time with our dogs on a day to day basis anyhow so our dogs had no problem being left with them. Although apparently they were a little sad when we were away.

I couldn't imagine leaving a pet with strangers although I'm sure some people in catteries ect.. do a fine job.