What Getting a Second Dog Actually Does to Your First Dog

We told ourselves Penny was lonely.

Looking back, I think we were projecting. Penny is a six-year-old Dachshund who had been the sole recipient of our attention, the only animal in the house, and the clear organizing principle of our household for six years. The idea that she was lonely was our narrative, not hers.

We adopted Rufus — ten months old, also a Dachshund — and brought him home on a Saturday.

Penny's response to Rufus was not heartwarming. It was a low, sustained grumble that she maintained for approximately four days whenever he came within six feet of her. She moved her bed to the other side of the room. She ate with her back to him. She glared at us with an expression that communicated clearly: this was not agreed upon.

Rufus, for his part, thought Penny was the most interesting thing in the house and expressed this through constant proximity attempts that she did not appreciate.

Our trainer, Dani, was not surprised. "You've just upended the entire social structure of her home," she said. "She's the resource guarder. She has no say in this new arrival. She needs time and space."

We had introduced them in our home — Penny's established territory — rather than neutral ground. We had allowed Rufus to follow Penny continuously instead of managing his access. We had compensated by giving Penny extra attention when Rufus was nearby, which accidentally reinforced her grumbling (attention = reward = keep grumbling).

Dani redirected us: separate spaces, controlled parallel time, reward Penny for calm behavior near Rufus, give her consistent "dog-free zones" where Rufus was not permitted.

By month three, Penny was tolerating Rufus at normal distance without comment. By month four, she was occasionally choosing to sleep on the same couch — not touching, but adjacent.

Month six: they played together for the first time. Rufus initiated. Penny participated for approximately ninety seconds, then walked away with the satisfaction of an animal who has decided when an interaction is over.

They are not best friends. They are housemates who have reached a workable arrangement. Penny is no longer grumbling. Rufus has learned to read her signals.

We would do it again, knowing what we know now — starting neutral, managing access, and letting the relationship develop at Penny's pace, not ours.

Multi-dog introductions require neutral territory and managed early interactions. Read our breed guide on Dachshunds for more on this breed's territorial tendencies.

The useful question isn't "would my dog like a friend?" It's "who is my resident dog, and does a second dog actually suit her?" The instinct that drove Heather and Tom — Penny must be lonely — is the single most common reason people adopt a second dog, and it is usually about the owner, not the dog.

Breed temperament is where the honest answer begins. Our Dachshund breed profile is blunt: the breed is bold, stubborn and "devoted to its people," bonds intensely — "sometimes to one person" — and on the site's own data is rated not reliably good with other pets. A dog wired to guard resources and attach to one human doesn't experience a new arrival as a gift; it experiences it as a competitor for the two things it values most, you and its stuff. That doesn't mean a second dog can't work — it means the resident dog's disposition, not your guilt, should drive the decision. (If you're leaning toward a different breed as the newcomer, our dog breed guides are the place to check compatibility first.) Penny, the resource guarder, was a textbook case: four days of grumbling was her stating exactly that.

Nearly every early failure traces back to the same avoidable mistakes — the ones the Blakes made. Well-established professional guidance is consistent on the fundamentals:

"Jealousy" is the human word; what you're actually watching is competition over resources and attention, which is why separating food, toys and space does more than reassurance ever will. Expect the adjustment in weeks to months, not days. Penny needed roughly four days to stop actively objecting, three months to tolerate Rufus calmly, and six to play — a realistic arc, not a slow one. Progress is rarely linear, and the target isn't instant best friends; many multi-dog homes settle into exactly what the Blakes got, respectful housemates. One breed-specific caution braids in here: the Dachshund profile flags a roughly one-in-four lifetime risk of spinal disc disease and warns against jumping and rough play, so an excited young dog egging the resident dog into leaping and wrestling is a genuine injury risk for this long-backed breed, not just noise. Watch, too, for signs that need a behavior professional rather than more time: stiff freezing, hard stares, snapping over food or space, or a resident dog that stops eating or hides.

This is the hope behind a lot of second-dog adoptions, and it's largely a myth. Separation anxiety is distress at being apart from a person, so a canine housemate usually doesn't resolve it — an anxious dog left alone tends to be just as anxious with another dog in the room. Our dog separation anxiety guide treats it as its own training problem built on gradual desensitisation to departures, not on providing a roommate. Adopt a second dog because it suits your household, never as a therapy prescription for the first, or you can end up managing two anxious dogs instead of one.

Heather and Tom's honest verdict — "we would do it again, knowing what we know now" — is the real lesson, and it isn't that Penny needed a friend. It's that the second dog worked only once they stopped managing their own guilt and started managing Penny: neutral introductions, controlled access, guarded resources, and a pace set by the six-year-old on the couch rather than by the ten-month-old who wanted to play. Six months in, Penny and Rufus aren't best friends; they're housemates with a workable arrangement, and for a devoted, territorial Dachshund who never asked for a roommate, that is a genuine success. If you're weighing a second dog, borrow their correction: choose for the dog you already have.