I voted no, no way, but have to add that would depend too...
If it were a financial crisis or serious illness then obviously cutting back would have to be looked at. Serious enough illness then I guess I would have to look at having the horses all gone.
But--if this were just his wishes--he wants to do something different or feels too much time is spent on the horses, or figures the horses are to blame for whatever problem exists in the relationship--then no.
I've seen it happen too many times that one partner insists that the other must give up her interest, be it horses or something else--she goes along with it & gives up the horses. Then not so far down the road /she comes to regret the fact that she gave up her horses. Generally it turns out that the real problem wasn't the horses--that was just the excuse given by the partner. Maybe he was already fooling around with someone else & chose to blame the horses to cover up his own fault/guilt, or perhaps he was just resentful of the time/money spent on the horses and figured if the horses were gone he'd get more attention--those are two scenarios. Usually it doesn't work--the horses are gone and the real underlying problem still exists.