July 15, 2026, 2:53 pm | Read time: 8 minutes

The crucial question isn’t “Does the second dog fit?” but “Do I fit?”

Most people considering getting a second dog primarily ask: Is my first dog sociable enough? Does he get along with other dogs? Does he have the right temperament? These aren’t the wrong questions, but they’re not the most important ones. Grewe sums it up: “The moment I feel the right thing, I’ll do the right thing.” What initially sounds almost too simple carries a clear core: The owner’s inner attitude is the foundation on which the entire multi-dog ownership stands or falls.

Of course, owning a second dog is possible, even if the first dog isn’t thrilled with the situation. It’s not a moral failing. “But it means you must be able to manage the resulting dynamics—and not just during the adjustment phase.” This requires clarity about yourself: Am I emotionally stable enough? Am I capable of taking action, even when things get tough? Do I have confidence in myself and my dogs—or am I someone who freezes in conflict situations?

What can go wrong with two dogs?

Owning multiple dogs can be wonderful. But it can also become quite exhausting in ways you hadn’t anticipated. Grewe recommends seriously considering all possibilities, not just the pleasant scenarios. Because the reality of multi-dog ownership sometimes looks like this:

• Walks become more complicated: You might not be able to walk both dogs at the same time—because of a lack of physical strength, because one dog isn’t reliably on a leash yet, or because the dynamic between the animals on the street isn’t stable yet. This means not one or two walks a day, but four or five. And suddenly, a large part of your daily routine revolves around the dogs.
• Illness and incompatibility are real scenarios: What if one dog gets sick and you lack the energy to do justice to both? What if it turns out that one of the dogs simply can’t handle multi-dog ownership—because he’s constantly suppressed, because he suffers, because he can’t thrive? Multi-dog ownership isn’t automatically fair for everyone involved.
• And then the question hardly anyone asks in advance: What do I do if it really doesn’t work out? Which dog do I give up, and where to? This question sounds harsh—but those who think about it before making a decision are better prepared than those who have to answer it in a crisis situation.
• Genetics play a role: Three Kangal males together statistically have a significantly higher conflict potential than three Shelties. This isn’t discrimination against breeds but a realistic assessment. Anyone bringing a second dog with high aggression or strong hunting instincts into the home—think Malinois or Cane Corso—needs not only experience but expertise.
• The social environment is part of it: Do children regularly visit? Do you share the apartment with people who might be less enthusiastic about a second dog? The question of what a second dog means for all family members is not a minor matter.

And finally: The biggest fear of many owners is aggression between the dogs. This concern is justified—but it doesn’t have to happen. However, there are also people who seek exactly this challenge. Those who want to care for difficult animals, who find joy in complexity. This is also a valid path if chosen honestly.

Also interesting: Do dogs need other dogs as friends?

Which second dog suits you?

If you’ve answered the questions described above and concluded: Yes, I want this, and I’m ready for what may come—then the question of the right second dog arises. Grewe’s recommendation is to orient yourself by the breed and its genetic predisposition. Not because breeds determine everything, but because they provide a reliable indication of what you might be dealing with. A second dog with high aggression or drive isn’t for owners who are still at the beginning of their dog experience.

If the first dog is generally sociable with other dogs outside, that’s a good starting point. Often, that’s all that’s needed at this point. You must be able to trust your own dog—even in moments that initially seem unsettling.

An example: The puppy heads for the old dog’s bed, and the old dog defends it. Many owners’ reflex is to separate the dogs immediately. But according to Grewe, that would be a mistake. The conflict just shifts and builds up. Dogs claim spaces, and the old dog is initially right. He has experience, knows the house, and has a position. Respecting this position isn’t cruel but wise.

Adolescence—when harmony is tested

Those who bring a puppy as a second dog into the home often think about the early days. The adjustment, the first weeks, getting to know each other. But there’s a phase that’s far too rarely considered in advance: the adolescence of the second dog.

“With adolescence, the dynamic between the dogs changes fundamentally. What began as a relaxed relationship can suddenly gain tension—especially between two males or two females. The statistically most harmonious pairing remains between a male and a female.”

But it’s also clear: If there’s a female in the household that goes into heat, you must have solutions ready: Can the male be housed with friends or relatives during this time? Can you handle the situation yourself? Is neutering an option? These questions are part of the preparation—not the crisis reaction.

When a dog trainer can help—and when they’re almost indispensable

If you’re generally unsure whether your first dog is suitable for a second dog, an experienced dog trainer is a wise investment. Grewe recommends involving a trainer from the outset. A good trainer, who has a confident dog themselves, can bring this dog into your home. This way, you can see how your first dog reacts to a strange dog in their own environment—after a joint walk, in a relaxed atmosphere. This gives you valuable information and a sense of what to expect.

Additionally, it can be beneficial to have a trainer accompany the entire process: from the decision-making phase to picking up the puppy and into the first weeks of living together.

More on the topic

Dog Expert Explains Common Mistakes People Make When Choosing a Puppy

Important Decision Should I Get a Second Dog? A Dog Trainer’s Advice

Training in multi-dog ownership: what really matters

Many dog owners think that if the dogs get along, the main work is done. In reality, the actual training work in multi-dog ownership begins at a completely different point.

At least once a day, you should do something individually with each dog. This applies to the old dog—who needs individual attention and routine—just as much as to the puppy. The puppy must learn to be alone. He must learn to pay attention to his human and not just the other dog. He must experience that his human provides security—in new situations, with unfamiliar noises, in unknown terrain. This is the crucial foundation for leading a good life with both dogs later on.

What happens if you don’t do this? A puppy that comes from a pack environment initially orients itself to the other dog. This is natural but can lead to the bond with the owner being weaker than desired. And if something happens to the first dog—due to illness or age—the second dog often suffers significantly. Those who invest in the individual relationship with each dog from the start prevent this.

Grewe also emphasizes that you must be able to influence each dog individually during walks. The training must be reliable; not necessarily perfect, but dependable. Both dogs must know that you make clear decisions and enforce them. This provides security and structure. And that’s what sustains a pack in the long run.

The most important thing in the end: Trust yourself

The advice culture around dogs is vast. Every expert has a different opinion. One recommends breed A, another warns against combination B, a third says you should never keep two females. The danger is great to become a pawn of conflicting experiences and ultimately make a decision that doesn’t feel like your own. Grewe’s advice: “Do what draws you. Decide with your feelings. Don’t decide out of reason, but from your emotions.” This means that those who are aware of their limits and possibilities can and should trust their gut feeling.