Extreme dizziness

  When out riding my horse today and fell off due to extreme dizziness as he was trotting up a hill just walking him I was ok with but as I said when he started trotting my whole world went spinning and ended up on the ground on all fours till the spinning stopped

I have been riding him for many years now and had never felt like that before so why is this up and down movement cause me to get the spins like that

[Caliber2005]

Hi,
There are lots of causes for dizziness. True dizziness is something like light headedness. What you would have experienced is balance instability or vertigo kind of thing.
Vertigo is the sensation that the room is moving or spinning, or that the person is moving or spinning within the environment. Symptoms are Sensation of spinning, room spinning sensation, Balance problems, Nausea.
Any ear disorder or eye disorder can also cause balance instability.
I think you should be seeing a physician at earliest and further to be referred to ENT specialist for evaluation.
Hope this helps.
Bye.