You can get supplements which really help, for example Equine America really helped my horse! Supplements with glucosamine are the best (I think it’s glucosamine anyway!) but it made a huge difference 🙂
There are many types of arthritis. There are natural treatments to relieve it, veterinarian treatments too, in osteopathy you have to deal with the horse in its integrality.
The horse has to stay balanced, so you have to rebalance with chosen choices.