I've always assumed they do, so try and walk mine in a different place every day of the week.
But I've noticed a lot of people seem to do the same walk everyday and today was speaking to a friend who does this and asked if she didn't worry about her dog getting bored.
She looked at me as if I was mad, and said Of course not, it's a dog!
Maybe I am mad? What do you you think?
BTW I get bored if I walk in the same place 2 days in a row, so it's possible this is more my problem than my dogs' problem!