I love including dogs in sessions, but always want them to be comfortable and make sure both dog and kids are safe. Mom described there pup as a grumpy old man.  I have a grumpy old lady of a dog at home myself.  She loves my girls, but as she has gotten older wants her own space.  I think she worries that they will hurt her.  She often is torn between wanting to be with us, but also needing her space.  There old man joined his family on the bed, but did not want to get too close, so we have some dog bum photos :).