How many grams is your snake?
If you are feeding her mice I must assume she is under 100g as most hatchlings can pound a pinkie rat with no problem.
If she is a small snake, I'm surprised you trusted her around a dog basically unsupervised.
If she's big and eating mice, there's your answer. She is underfed and hungry for Mexican.
Definitely scary, though. Glad no injuries came out of it.
EDIT #1:
Just reread the post. Curious as to why she is eating mice at 900g. Picky eater? I would recommend ASF as an alternative to ensure she is getting the proper nutrients.. Mice are very poor in nutrients.......