I have a mountain smith back pack for my boy. Works well, but I rarely use it. Lots of room for stuff but I tried it a few times for his training stuff and its just annoying to put it on and off of him. Won't put it on him on hikes in the woods because I want him to run freely and don't want the backpack to get caught on anything and rip. In the summer when its hot I sometimes throw it on him with frozen water bottles or just cold water bottles...that way we have cold water and he stays cooler, but even that happens very rarely.
It's a cool thing to have, found mine on amazon and it wasn't too expensive, good construction as well. I got a medium...don't go bigger than that. I have an 85lb male and it fits him just fine. I've just come to realize its easier for me to grab a back pack and put stuff in it than to strap that thing on him, then take it off when we're doing something, then put it back on, ect. Your idea about the dog park, while in theory its good, in reality you'll end up taking it off your dog and carrying it around (so its easier to carry a human backpack). If you leave it on, some other dog will come by and rip it off for you, or shred it while your dogs are wrestling.
If you're going to continue using the forum...learn that people will comment and give their input on your whole post not just the question you ask. Either take their advice, or ignore it completely, no reason to tell them that you're not interested in their opinion about something else you wrote.
Last edited by martemchik; 01-11-2013 at 02:31 PM.