You could always get an extra dog collar and some rubber chew toys, but those usually appear years later into a marriage. *rimshot*

If he goes for runs or walks and is around dogs he likes, you can give him doggy treats he can hand out like candy :P

Of course as children, pet food is also kid food too... I've eaten cat, dog and gerbil food. So it wouldn't be too far to just get milk bone treats if he's into that type of thing or ever was as a kid.

There are too many to mention gift ideas for dog lovers. I'm a dog mom too and the best gift I received is a cap and shirt print with the photo of us and added with funny text. And my dog also has one like mine. That is so cool!