UNDER NO CIRCUMSTANCE WOULD I ATTACH A LEASH TO THIS PACK !I bought this pack for a hyper-kinetic rescued dog (lab/chow mix) I have been working with. When the pack arrived I set about fitting it to the intended wearer, and then I loaded it with a water bottle and a can of dog food on each side. I found the straps a bit difficult to adjust, and could not get a completely satisfactory fit, but this is a one time process. When I set about loading the pack I was particularly disappointed by the zippers. They were of very poor quality, prone to jamming, and they seem likely to break. Overall, there is a feeling of cheapness to the straps and fittings as well, although the pack material itself seems adequate. With care, I think this pack is usable, but I am worried about the possibility of a zipper breaking at an inopportune time. If I were looking for a dog pack to be used for serious trail hiking I would look a bit more. For a pack simply to help give a dog focus, or to carry a few items for an afternoon outing, this pack would be acceptable.As far as using dog packs, the result can be impressive. This dog, while I have been working with him for about 6 weeks, is by nature a high energy animal. He knows the rules, and obeys commands quite well. (I can put him on my sidewalk, drop his leash [ground tethering] and go in the house. When I come back ten minutes later, he will still be there, and will remain until I give him a release command. But on walks, his need to move forward, and his desire to be the lead dog, cause him to make repeated small challenges to my leadership. He isn't a bad dog, by any means, but he has a desire to be dominate (despite being neutered) and you find yourself wishing you had some "doggie-ritalin" in your pocket.The pack, however, makes a dramatic change. It as if all that excess energy of the past was directed at finding something to be doing, and now, at last, he has found something. He becomes focused, almost serious seeming, but in a very relaxed and mellow way. He maintains his position during the walk, focuses more on my leadership, and is no longer trying to slip into taking the lead. I guess everyone needs a sense of purpose in life, even dogs. Horses too, seem to benefit from "having a job". My cats, on the other hand, see their job as finding things for me to do, and being in charge of everyone else.Overall, if you are looking for an inexpensive pack simply to help your dog be a bit calmer and more focused, this pack will work. Be careful not to overload your dog, as this pack isn't exactly an orthopedic marvel. A couple of water bottles and a "free sample" bag of dog food would usually suffice, they just need to feel that they are carrying something, not simply wearing a funny coat. Be sure the load is balanced between the two sides. I like to always include a little dog food, and I make sure that they sniff it and see it go into the pack. After all, what would make more sense to a dog than carrying food? (The answer is: "carrying something really smelly we could all roll around in", but we're not offering our dogs that option!)The dog pack industry could stand to take a few lessons from the saddle industry on protecting the animal and making sure of their comfort. If people are willing to spend thousands for a top quality horse saddle, there should be a market for a top quality $100 to $300 orthopedic dog pack. I would pay that, or even a bit more for a *very* well engineered and manufactured product (but not a gimmicky one - it has to be the "real deal"). But there is also certainly a need for inexpensive packs like this one to be used on moderate walks with light loads.In summary, I would buy this pack again for the intended purpose, but it would be nice to find something with better zippers and straps.