I have a 20 year old gelding that I started on his first joint supplements just last year. My vet recommended him to be put on an oral and intro muscular injection, due to his high activity level and the fact that I still haul him several times a month. Even though he didn’t show any obvious signs of discomfort or pain.
So he is on every option possible to give him the best comfort possible. I think activity level plays the biggest role in which route you go. I also don’t believe that a young horse should be started on injectables if an oral supplement can get the job done. I will swear up and down that Adequan help my old man in more ways than I thought possible. Although I think his oral supplements really helps with any discomfort after workout. It’s a toss up. Smartpak has an amazing line of oral supplements. If I had a younger horse (say mid teens), I would defiantly go oral supplement first. Sorry, this probably doesn’t help at all, I kinda just rambled on. Haha. Hope you find a good combination!