8:52 p.m. on October 12, 2011 (EDT)
I have owned and trained purebred, some champion, large breed hunting and working dogs from age 8 to my current age of 65. I have largely specialized in Rottweilers from age 40 to the present and have had my dogs on Canadian Coast Guard Lightstations on remote islands, BC Forest Service fire lookouts and in many other wilderness and stressful environments. I have also been on several long, wilderness horsepack treks for a fortnight in some of North America's most remote mountain wilderness and packed my own horse.
I used to carry loads approaching 150 lbs to 7000 ft. firelookouts in the BC Rockies and have backpacked 100+ lb. loads of meat and gear many times. I can quite easily carry 90 lbs. for hours in most terrain and this is a moderate load in much wilderness backpacking when hunting or working. I need to condition for this as I did not used to bother when younger, but, it is not that difficult and I rather enjoy it.
Otto is right, my current male, just past four years, mighty "Trojan's Diamond in the Ruff", weighs about 125 lbs., went V-1 in his first and only show and can easily carry 75 lbs. My bitch, Canadian Champion Von Kruzenhaus's Quean Lily Lovelyface, can at a good 90 lbs, can pack 50 lbs. and still scamper along like the little scamp she is.
My dogs have ALWAYS lived far longer than those of my friends and colleagues and I constantly receive compliments and questions on them and always have. I DO NOT ABUSE ANIMALS and local breeders of purebred Rottweilers often OFFER me FREE dogs due to the quality of the home I provide and my ability to gently handle even big problem Rotts that others have mishandled...I can document this, of course.
I would NOT pack a big dog, such as a Rott, Bouvier, Pyrenees, Swiss MD or Owcharka, with more than 15% of body weight UNTIL he is past THREE and then slowly work up to what I felt that dog's maximum weight is and that does differ between apparently equal specimens of the same breed as abilities to perform physical activities does among humans...ie, few can fight like Joe Louis.
It takes some actual field experience to learn what really can be done by dogs, horses and even people and a good dog can perform in tough country like no other animal, given the right breeding, care, training and AFFECTION. Mighty Cisco, WANTS to work, all good Rottweilers do just as good hunting breeds want to hunt.....just like the best people.