Have you pursued legal action with the company? Did you choose to use Quest this time to try to target a specific parasite? Do you mean that you gave your mare ivermectin routinely, and this was the first time you gave her Quest? Or that she was wormed with ivermectin and then Quest within a day this time? Did you have your vet do fecal counts and then worm them? Or do you worm them on a schedule basis?