"Ohhh... oh dear..." Gertrude mutters as she climbs back to her feet. "I must be dreaming... I knew I shouldn't have eaten that leftover casserole..."
"No, you're not dreaming..." Mary says as she idly leans against the fence, thinking quickly for an excuse, or at least quickly relative to her cowlike mind. "I'm a... a... were-cow, like a werewolf, but a cow, see... and this happens every once in a while. It's no big deal, but you have to keep it secret, promise?" Knowing the gabby old lady, Mary figures this is an unlikely promise for her to keep, but either way she's not terribly worried.
"Oh... I... yes, I promise. I'll keep it secret. Your secret is safe with me! No need to worry..."
"Yeah, thanks." Mary nods her head and hops down from the fence to all fours to continue grazing some more. She got hungry again, so she might as well eat. Having multiple stomachs will do that to a girl.