I wish ethics were the issue but seeing some of the mouse studies that "pass" is quite depressing. I expect it's the cost, facilities, and logistics of keeping

I wish ethics were the issue but seeing some of the mouse studies that "pass" is quite depressing. I expect it's the cost, facilities, and logistics of keeping multiple horses for multiple decades. It would literally be proposing the equivalent of starting a long term small business with an up front cost in the low digit millions (you need to purchase a small farm).