do not shave it. it will ruin the hair shaft and the fur will be ruined and bristley. the dog has long hair for a reason, it actually keeps the heat out. shaving it will make the dog hotter because the sun will be able to touch the dogs skin. just because the dog pants doesnt mean its uncomfortable, thats just how they sweat. most groomers wont shave a dog like that.

(personal experence, i work at a groom shop)