I'd like to preface this writing by reminding everyone that I am no horse expert. BUT, I did stay at a Holiday Inn last night, so...
I am now going to espouse my opinions, based on observation. Specifically, I want to address the issue of a horse's cantering, or rather their willingness or reluctance to do so.
Have you ever considered this test? What would your horse do if you caught him from the pasture or stall, picked his hooves and tacked him up, mounted him, and then proceeded to canter the horse away from the barn? This is without any warm up, absolutely "cold back" riding.
Now I'm sure some of you are starting to shudder at the mere thought of trying this test with your horse. And I'm not suggesting you try it. But I'd be interested to hear your response. And I'll tell you what each of my horses would do below.
My 17 year old gelding, Woody, would canter off easily. He might get high-headed for a bit, but there would be no tail swishing, no cow kicks, and no bucking. I consider this the gold standard. This horse is truly good and broke. He side passes both directions, trailer loads and unloads without difficulty, leads well and will trot while led, yields his hindquarters, will cross over his front legs, stops with my seat, rides collected, neck reins, and rides best in a curb bit. He picks up his feet for picking like no horse I've ever seen. His only fault is that he can get high-headed until reminded to flex at the poll, and he has no cow in him. But by every measure, he is a completely broke horse. He has NEVER in the time I have owned him, bucked, cow kicked, or reared when asked to do anything. Enough said.
Now for the another end of the spectrum, my newly acquired, 4 year old gelding Joey. He is a good horse. But if I were to canter him off cold backed, and I hadn't worked him in several days, I would be grabbing for my night latch just in case he might buck. He's not a bad horse, but he isn't completely broke. He might buck, he might not. But I don't have the confidence in him that I do in Woody. Joey is only fair (but getting better) at trailer loading. But I can't say that I've successfully loaded him in every kind of trailer. He picks up his feet well, without any tail swishing. He side passes well. But he still has trouble with lead departures and he tends to lift his head when changing gaits. In other words, he has great potential, but he still has a lot to learn, and therefore I don't consider him completely broke.
My other two horses are in the middle of the spectrum, but closer to truly broke.
My point is that too often I hear people making excuses for why their horse cow kicks going into the canter. Or a horse that bucks when asked to canter. Or is reluctant to canter. I'll bet you good money that those same horses don't do a LOT of things well. It would be a rare horse that can do everything that my horse Woody can do AND still cow kicks or bucks going into the canter. To me, showing tail swishing, cow kicking, bucking going into the canter, are all just signs of willful disobedience (assuming always that health issues have been eliminated).
Now don't get me wrong; it's not that I think the horse that shows reluctance to canter is a "bad" horse. In the case of my horse Joey, he's just young. He sometimes goes too long between riding, and he has to have the "fresh" worked off him before he performs at his best and gets "right in his head" and submits to my leadership. But I do NOT imagine for one second that he isn't a potentially dangerous horse, or that he is safe as my bed at home and a truly broke horse. He is NOT.
And just because a horse is older does NOT mean they are truly broke. Older horses can be as dangerous as young ones. But I DO think even the best of young horses cannot be considered truly broke until they have some age and miles on them. It's just that they don't have enough experience. A 4 year old that shows great temperament MIGHT be a future Woody, but I can't say that at 4 years of age. Too much can still go wrong, there are too many new experiences that might overwhelm a younger horse.
So if your horse can't do all the things that Woody can do, if you can't jump on your horse cold back and canter away from the barn, then stop fooling yourself that you have a dead broke, safe as your bed at home horse. What you have is a horse that is still dangerous, and needs your work and attention.
So what are you going to do to make your horse super broke? Do you even care if your horse does the occasional cow kick or buck going into the canter? Have you given up on cantering because you fear what will come next? Have you become satisfied with walking and trotting only?
Like I warned at the beginning of this post, I am not a horse expert. But I am stating firmly, in my opinion, unless your horse canters without any expression of reluctance, you have work to do with your horse.