A 6 month old fila left with total strangers for a week? Who harmed it under who knows what circumstances? (from the dog's perspective, with the e-collar) I absolutely find it believable that in those circumstances an otherwise stable fila puppy would develop major issues. Properly used, I've never heard of an e-collar being used to train dogs under a year old. I don't know if this lady's fila was stable to begin with, but yeah. And correct filas are not typically dog aggressive. They've got a generous dose of bloodhound in their ancestry and are expected to work well with other dogs. They're one of the very few molossers that tend to be fine with other dogs.