DOG TRAINING TIPS:
When Friendly Dogs become Predators: Predatory Drift
Call it "predatory drift” or just typical dog predatory aggression, dog owners need to keep this concept in mind before allowing dogs of different size/weight play together. The rule of thumb is no more than double the weight of the smaller dog.
Predatory drift or predatory aggression happens when a large dog who is friendly and playing with a small dog suddenly perceives the small dog as a prey animal. The dog’s brain will one moment be in play mode then instantly switch to it’s ancient predatory instincts to hunt and kill. It can be triggered by a dog who is much smaller and looks, sounds or acts like prey. The larger dog may grab and shake the small dog like they would a toy. This predatory drift situation can occur even in a dog who has never before been aggressive.
Sounds pretty scary especially since it happens without warning. It can happen with casual doggy friends or even members of the same household.
You can avoid this predatory aggression/drift situation from happening by not allowing large dogs to play with much smaller sized dogs. Doggy Daycares should avoid mixing large and small dog breeds together. Off-leash “dog parks” may not separate dogs by size, so either avoid them or only use them if only the dogs present are of a similar size to yours.