The worst pony book title ever
I would think it has to be Myrtle Green's "A Pony - Doctor's Orders" which succeeds in sounding like a breathless Mills and Boon. I can see it now. The tweed suited vet, his dark face twisted in a handsome sneer, tells the beautiful but bedraggled groom, hanging on desperately to the head of the plunging thoroughbred, completely failing to hold him steady as the vet does something Extremely Important: "A pony - that's all you're fit for. You'll never be woman enough for a horse. Or for me."