The REI Ultra Dog Pack is suited for big day trips or multi-day excursions, though it does have a smaller volume than the other packs tested. The simple design, fit, and way the pack carried a heavy load made it my early favorite.

Fit
In particular, I liked how the cam lock feature at each buckle makes the pack easy to throw on the dog and quickly adjust. Unfortunately, my more adventuresome dog was able to make the camming features fail with her off trail antics. It appears that it is possible for brush and sticks to release the camming function. Both under the body straps had their cams pop open, but the pack did stay on because of the sewn webbing ends.

Handling
The pack has a large loop handle on top that is advertised as a “mini lead.” I didn’t love this design. The back of the loop is connected to the harness with a Fastex buckle. Releasing this buckle does not greatly extend the length of the lead. With the loop Fastexed down, you would think you could use the part that sticks up as a lifting handle. However, as you grab the handle and lift, the loop slides through the Fastex buckle and bunches up the harness.

I found a more ideal way to lift the dog is if you grab both the top AND bottom part of the webbing that makes up the handle loop. Then, it does work quite well to support the dog over obstacles.

Features
The aluminum attachment point, water resistant zippers and the hidden compression system also worked well for me. Overall, the pack seemed very comfortable on the dog, with a simple, lightweight design with just the right amount of padding.