There are so many similarities between Mindscape's Dogz and Catz titles that there is almost no point in writing this review. If you were to substitute all references to "catz" with "dogz" and change minor details like replacing "yarn" with "stick," you would end up with exactly what Saffire has produced.
That being said, Dogz is a virtual-pet-type game for the Game Boy. After a visit to the pound, you can choose a dog from one of three different types (mutt, Scottish terrier, Chihuahua) then move it to a virtual playpen, where you must take care of it. You can name your dog, brush it, spray it for fleas, throw it a bone or stick, and feed it as much as you'd like. Your dog has a list of stats (happiness, health, affection, and so on), which you must maintain to keep it as a pet. If one of these bars falls into the red for too long your dog will defect to someone else's virtual pen. Naturally, you can alleviate these negative emotions with care appropriate for your pooch (pet it to raise its affection for you, feed it if it's hungry, etc.), but, sadly, the interactivity with your cyberdog ends there.
Your dog's stats change very slowly over time, so there's really nothing to do other than to turn your Game Boy on, watch your dog run around the screen, and wonder why you're wasting your time with this title. It's not a game in the truest sense of the word; instead, it's more like an exercise in philosophy: Why did this title get made? Will people really play it? Will schoolchildren care about it when they could be playing Pokemon instead? What else could I be doing with my time?
If you've come this far, feel free to read our review of Catz, the sister cart to this "game."