Introducing puppy to bigger dog in home

[Danica Liebold]

I have a 50 pound 9 m old puppy and will be getting a 6 pound 10 week old puppy in couple of weeks and am concerned about larger dog playing to rough or sitting, laying on her. How do I train larger pup to be easy with her. I have another older small dog that keeps him in line and 2 cats that let him rough house with them and they keep initiating the play but don’t want new smallest puppy to get run over. 

[Adrienne Farricelli]

Hi there,

Welcome to the forums!

A nine-month-old, 50-lb adolescent dog and a ten-week-old, 6-lb puppy are operating on very different physical and neurological settings. The older dog is in the canine equivalent of the teenage phase, that is high arousal, strong play drive, and still learning impulse control, whereas, the younger puppy is developmentally fragile and lacks the coordination to protect herself. The concern you’re raising is therefore legitimate; injuries between puppies in this kind of size mismatch are entirely possible, but usually occur accidentally rather than through aggression.

The first principle is management, not training. The older puppy should not have free access to the smaller one during the first weeks. Use barriers such as baby gates, exercise pens, or crates so the dogs can see and smell each other without physical contact. This prevents the older dog from rehearsing overwhelming play while the small puppy is still settling in.

Controlled introductions should be brief and structured. Keep the larger dog on leash initially and allow the puppies to interact for only a few seconds at a time before calling the older dog away and reinforcing calm behavior. The goal is to teach that disengaging from the puppy earns reinforcement. Many young dogs can play appropriately, but they need frequent interruptions because their arousal escalates quickly.

Teach the older puppy a few specific impulse-control skills before the new puppy arrives. A reliable “go to mat,” “leave it,” and a recall away from play are extremely useful here. When the small puppy moves around the room, reinforce the older dog for choosing calm behaviors such as lying down, sitting, or observing quietly. This builds a habit of settling rather than charging toward movement.

Supervise all play sessions closely. Healthy puppy play includes loose bodies, frequent pauses, role reversals, and self-handicapping from the larger dog (for example lying down or reducing intensity). If the larger dog begins to chase, body-slam, pin, or ignore the smaller puppy’s attempts to disengage, calmly separate them and allow both dogs to reset.

Do not rely on the older small dog or the cats to regulate the adolescent dog’s behavior. While some adult animals will correct a youngster, it is not fair or safe to expect them to manage interactions with a vulnerable puppy. Human supervision should be the primary control system.

Finally, remember that fatigue and excitement both increase the risk of rough play. Short training sessions, sniffing activities, food puzzles, and walks for the older puppy will lower baseline arousal and make gentle interactions more likely.

With careful management and reinforcement of calm behavior, most adolescent dogs learn surprisingly quickly that the tiny newcomer is not a wrestling partner but a fragile member of the social group. The important piece is preventing the older dog from practicing overly rough play during those early weeks while the small puppy is still physically delicate.

I hope this helps!

Happy training!