As someone who know practically nothing about horses, it does seem horses are the most delecate things on earth and how they have survived in the wild is beyond me. I have learned that horse vets must be millionaires. If we had listened to all the armchair Vets, cinny would be dead by now! Cinny has been dianosed by other non-vet horse owners as "lame" he has "arthritis" and dozens of other ailments! But it seems he is fine. Cinny slipped and did the splits with his rear end some time ago and he stood up and lifted one of his rear legs. His leg was heated and we helped him "walk-off" his mishap. Now he is perfectly fine. I do give Cinnys Whinny a raised eyebrow now and then when she comes out with "he could die" or "he can colic" or he can "go lame". What the hell is going on with these "glass horses"?
I know this thread is a little "aged" but I thought I would answer you a little bit. Yes, horses have survived in the wild for years. Yes cowboys put them through some pretty rough stuff and to an extent, they did survive. However, the average life expectancy of a horse in those times was roughly about 10 years. Why, because they would suffer illnesses, injuries, etc and either die of said injury or illness, or die because of it leaving them vulnerable to a predator who would find them and have them for lunch (and I don't mean as a guest).
Nowdays, horses in captivity have it good BECAUSE they have caring people who keep injuries from becoming causes of death. In the wild a horse would eat something bad, and chances were they would die a horrible death of colic or poisoning within a day or so. Nowdays, we prevent them from eating bad things, and in case they do a vet can give it something to help it get over the poisoning or colic. Back then a horse would come up lame, and that was the kiss of death. Today we have medicine to not only prevent it, but to help the horse when something bad happens.
Back then, we treated horses as if they weren't expected to live long, and as if they were a little more disposable. They were tools, vehicles to get a job done. When they broke down, they were replaced. Today, horses are a family member, we love them, and we want the best for them. They are no longer replaceable so we take better care of them. Today horses have a life expectancy at least twice what it used to be and still, it's nothing to hear of a 25 YO horse these days, even 30.
Oh, and sorry for hijacking the thread...