I have a Mini Schnauzer and a Border Collie-Heeler mix, both rescues, and they just turned three. I got them around the same time, though it wasn’t planned—they kind of just ended up with us. Ever since we got the bigger dog, our Mini Schnauzer has had a habit of going into a “red zone” whenever he gets hurt. For example, if someone accidentally steps on his paw and he yelps, he’ll go after our other dog. The same happens if the other dog is throwing up. Other than those moments, they’re perfectly fine together—they eat in the same room, and they even cuddle all the time. We’ve been working on correcting this behavior by putting the Schnauzer in time-out and it’s improving, but I’m still confused as to why it happens. Besides this, neither dog is aggressive, and the bigger one is probably the most submissive dog I’ve ever owned. They used to play together all the time, but now, since the Mini Schnauzer started attacking after getting hurt by the bigger one by accident, they don’t play anymore.
That sounds tough. It could be redirected aggression stemming from frustration or pain. Have you considered consulting a behaviorist? It could help get to the root of the problem before it worsens.
It might be a good idea to record the behaviors and talk them over with a vet, trainer, or behavior specialist. When describing the dog’s actions, try to be specific rather than using broad terms like “red zone” or “go at,” since these may not be clear to someone who hasn’t seen the behavior firsthand.
Did your mini schnauzer bite your other dog aggressively?
How did you break up the fight?
What steps did you take to treat the injury?
How did your other dog react to the attack?
How did you manage the schnauzer afterward?
How long have you had both dogs?
Were they from the same household before you adopted them?
Has the larger dog ever stomped on the Schnauzer? I have a maltese and a boxer mix, and the maltese is wary of the boxer because of this, despite the fact that they get along well normally.