Are two dogs better than one? What the social support study really shows

Reading time: about 7 min

My first dog lived as an only dog for almost ten years. That seemed perfectly normal until, one day, I brought home a second dog. Only then did I really begin noticing how much dogs can communicate with one another, watch each other and simply spend time together. Looking back, having just one dog somehow seemed sad to me. But that is my feeling, not evidence that every dog necessarily needs another dog alongside it.

When Dr Karen Shaw Becker wrote about a study linking dogs’ health with their social environment, it immediately caught my attention. The idea that another dog might benefit health fitted my own experience. The real question is broader, though: does the study tell us all to get a second dog, or is its message more nuanced?

A study of 21,410 dogs: what association was actually found?

The Dog Aging Project study published in 2023 analysed owner-reported data on 21,410 dogs. The researchers examined five dimensions of the social environment, including financial and household difficulties and social support. In their model, greater social support, one example of which was living with other dogs, was associated with better owner-rated health after accounting for the dog’s age and weight.

The authors noted that the strength of the association with social support was about five times that of financial factors in their analysis. That sounds impressive, but the figure needs to be interpreted correctly. It does not mean that another dog improves your dog’s health five times more than money or veterinary care. It was a comparison of the strength of associations between variables in a statistical model, not a controlled experiment in which one dog was given a companion and another was not.

That is both a strength and a limitation of the study. A very large dataset helps reveal important patterns that smaller studies can miss. However, much of the information relies on owners’ assessments, and other factors may influence the association. People with several dogs, for example, may also differ from single-dog households in their time use, experience or choice of dogs. The study does not establish causation or measure whether every dog enjoys living with other dogs.

What other environmental factors played a part?

The researchers also found associations with household and neighbourhood stability, the owner’s age and living with children. For example, in some analyses, households with children had fewer diagnosed diseases but poorer owner-rated canine health. This may partly reflect differences in access to care, time or reporting habits, but the study cannot definitively identify one explanation.

That is an important reminder for dog owners: the number of diagnoses and actual health are not always the same thing. A dog that attends frequent check-ups may receive more diagnoses precisely because it is monitored more closely. None of these environmental associations makes financial circumstances or regular veterinary care unimportant.

Dogs are social animals, but what company suits them?

I believe that interacting with another dog offers something we cannot provide in quite the same way. Another dog understands body language, invitations to play and signals about resting differently from us. But a social need does not create an obligation to share a home around the clock with an unfamiliar or unsuitable dog.

Some dogs enjoy another dog’s company but need more time alone. Another may be an exuberant player, while a third prefers a quiet sniffing walk and has no wish for a young puppy to jump on its back. Age, past experience, pain, stress and temperament affect compatibility. If an older dog already struggles with mobility, bringing home a very energetic puppy can be difficult for everyone.

Faddy and Oscar: a good match is not automatic

I have been very lucky with Faddy and Oscar. They may sleep with their heads and paws close together, and they have not had serious disputes over food in our home. But I also know families whose dogs need to eat in different corners, sleep separately and have space of their own. That, too, can be a perfectly workable two-dog household when the owner notices the signals and arranges the environment around the dogs’ needs.

I have also noticed that walking together and having individual time do not replace each other. For a while I walked my dogs separately almost every day, which took at least two hours altogether. They were together again on our Sunday forest walks. On an individual walk, one dog can focus on me and I can notice its needs more clearly. That worked very well for our family, but it is not the only possible routine.

Does being the same or opposite sex affect compatibility?

I have usually preferred dogs of the same sex because living with a female and a male during the female’s season can create quite a logistical headache. Dr Becker, by contrast, has highlighted that an opposite-sex companion may suit some dogs better. Those views are not necessarily contradictory: one concerns organising everyday life, the other the potential compatibility of a relationship between dogs.

A study of 38 cases of aggression between dogs in the same household is often cited. In 30 cases, the dogs were of the same sex. However, 68% of cases involved at least one female, not necessarily two females. These cases came from families referred to a clinic for problem behaviour. They therefore cannot establish the probability of conflict among all same-sex dog pairs or demonstrate that opposite-sex dogs always get along better.

Alongside sex, I would give at least equal importance to each dog’s temperament, age, energy, previous relationships with other dogs and the ability to provide safe separate spaces. If both dogs can move away when necessary, preventing tension is already easier.

How do you bring a second dog home?

The first meeting could take place somewhere calm and neutral, where neither dog immediately needs to defend a bed, a bone or the owner’s attention. I prefer parallel walking at first and an opportunity for the dogs to investigate each other at their own pace. There is no need to force them nose to nose. Even a friendly puppy is entitled to space, and an older dog’s patience should not be tested endlessly.

At home, establish separate feeding places, resting areas and rules for valuable chews from the start. Scattering treats over the floor is not always the best way to encourage friendship. If you see freezing, staring, blocking with the body, growling or conflict over resources, increase distance and, if necessary, seek help from a qualified behaviour adviser. Do not punish away warning signals: they provide a chance to respond before a bite occurs.

What if I cannot or do not want to get another dog?

That does not automatically mean your dog is lonely. Suitable social contact can also come from walks with familiar dogs, a calm playgroup or simply meeting a compatible companion. Some dogs’ best friends are people, and their wellbeing is supported by a safe routine, suitable exercise, sniffing and opportunities to rest.

Social support can be very important without being reduced to a single recipe. The question is not whether you have one dog or two, but whether your dog has enough safe relationships, freedom to choose and peace.

Two dogs can be wonderful, but they are not a universal health prescription

I would not trade Faddy and Oscar’s life together for anything. Watching them interact shows me every day how much a good canine companion can offer. But a study of 21,410 dogs does not mean every single-dog household should immediately look for another animal. The evidence tells us that the social environment is associated with health. We still have to build an appropriate life around the individual dog’s needs.

And there is one point on which I completely agree with Dr Becker: if there is not enough time, space or stability at home, a new dog is not the answer. Just as a new child does not solve a couple’s relationship problems, a second dog does not automatically solve the first dog’s loneliness. A good companion is a gift when both dogs feel comfortable in the relationship.

Sources

McCoy, B. M. et al. (2023). Social determinants of health and disease in companion dogs: a cohort study from the Dog Aging Project. Evolution, Medicine, and Public Health.

Wrubel, K. M. et al. (2011). Interdog household aggression: 38 cases (2006–2007). Journal of the American Veterinary Medical Association.

Bark & Whiskers / Karen Shaw Becker (2023). Living With Another Pet Affects Your Dog’s Health.