I have seen the most calm well trained horses freak out over treatment.
Anddddd then there are the other horses... like the client that wants you to castrate her 3 year old colt that is in that pasture and had never had even a halter on... good luck trying to sedate it!
From my experience there are less gates and restraints with horses... and I have seen horses that are in veterinary clinics rear up and put holes in the ceilings...
Sometimes its just freak accidents. I have seen someone give a horse penicillin and the horse had an allergic reaction and fell on top of the tech. She was out of work for months.
I know you give cows shots generally in the chute. Its way easier.
But one thing for sure is that I do not want to die trying to treat a horse or a cow....
As someone who works regularly with horses and loves working with cows, I think you are grossly underestimating cows.
I don't like horses. They're too dumb and panicky for my liking (NO OFFENSE TO HORSE LOVERS!!!) But the majority of horses are fine, and easy to work with. The worst injury ive ever sustained is having one accidently stand on my foot. And most of the time, if its getting really bad... chemical restraint is your friend...
Cattle, on the other hand...
I've been slammed against head bails more times than I care to remember. It really knocks the wind out of you and one time I cracked some ribs. I've been kicked heaps - but if I stand close enough to get kicked I always stand right up behind them, so it doesnt hurt. The amount of times I've nearly had my arm/hand crushed trying to inject/eartag/drench etc. In all fairness though, I've done a lot of cattle work on extensive stations in northern australia, where the cattle only see humans once a year, for the muster. These cows dont play nice, lol, and it certainly doesnt matter if they are in a chute! the chute is over 2m tall, and then some of them still jump out!!!
Not only that, but a lot of horse practices have horses come to them, and if you are really in a tight spot with a horse on a farm, you can usually get it transported to your practice where you should have stocks. No such luck for cows - I've preg tested cows in a race before, with no headbails, no kickgate and nothing to even stop the cows going backward and running me over... there was a lot of pushing and grunting and swearing that day!
Either way, big animals are exactly that. Big. no matter how nice they might seem - equine OR bovine - they have the potential to kill ANYONE who works with them. It doesnt matter how big you are or how strong you are - when it comes to restraining 500kg of whatever, if that 500kg decides it wants to go elsewhere, NO human has a chance. Sometimes being small in LA is actually an advantage - small hands, slender arms, and - I'm 6 foot - no awkward sway-backing when you preg test. I love love love cattle work, but after a day preg testing, your arms ache and so does your back. It doesnt matter how strong you are, how big you are, large animal work of any kind is tough on the body. And you have to be prepared to accept that.
NB: I've worked as a SA tech for 6 years. I've got some cracking scars from cats, and I know a lot of people who've suffered significant injuries from dogs (ie, dog bites that have developed into tendonitis). So everything has its risks.