Alvin's Locked in the Bathroom

My mom boiled two whole chickens (show off) and made a rice and chicken concoction for the dogs.  Alvin loves it but it's giving him absolute fits because he can't eat it in mouthfuls and ends up spitting most of out.  Not only does it create a mess but about nine years later, he finally finishes his meal.  Stevie is able to pound the food down and then acts like a crazed lunatic as she approaches Alvin's bowl and lunges for his food.  I have tried every which way to fend her off but it's useless because Alvin takes one little bite, spits it out, and then goes to each piece of rice and tries to eat it again.  It it such a mess that I can't feed him in one of the carpeted bedrooms and so out of desperation, I locked him in the bathroom to finish eating today.  It turns out that there is a huge gap between the bathroom door and floor, which I had never noticed before because I have never been on my hands and knees trying to peak into my own bathroom.  But there I was, craning to see if Alvin was indeed eating or just circling himself silly.  It turned out to be a combination of both.  He must have enjoyed it though because he let out a burp so loud that I think it put a dent in the door.  So, now he will be in the bathroom when eating my mom's home cooking, which ironically is where I often end up after eating my mom's cooking..........ducking now.