What age is right to adopt a dog?

For a puppy, never before 8 weeks (2 months) : that's the legal minimum age in France, and those weeks with its mother are decisive for its balance. An adult dog, on the other hand, can be adopted at any age, and training stays possible for life.

Is a shelter adult dog already trained?

Not necessarily: 'adult = already trained' is a myth, many arrive with no basics at all. The good news is that a dog learns at any age. You start gently, 'like a puppy', to find out what they already know and guide them through the rest.

Male or female, puppy or adult?

Choosing and welcoming my dogPart of · Choosing and welcoming my dog

Male or female, puppy or adult?

Q: Should you get a male or female dog?

Neither on principle: character depends mostly on the individual and the training, not the sex. Aim for a sociable dog who fits your lifestyle, male or female. If you already have a dog, a male-female pairing is statistically the easiest to live with.

Q: How do you choose a male or female dog?

Look at the individual first (sociability, energy, excitement threshold) rather than the sex label. With an unspayed female, plan for two seasons a year. Spaying or neutering is decided with your vet , for health reasons, not to 'control' behaviour.

Q: Puppy or adult dog: which to choose?

A puppy means everything to build (house-training, being left alone, socialisation) and a lot of energy: plan for several weeks at home when they arrive. An adult gives you a character that's already in place and lets you skip the most physical phase. Neither is better, one simply fits your life better.

Q: Male or female for a second dog?

Male-female is the easiest combination statistically; two males or two females is possible but trickier. Above all: if your first dog is reactive with other dogs, don't get a second one before you've sorted that out with a trainer.

6 min read

We often expect a male to be "dominant" and a female to be "gentle". The figures say otherwise: a 2022 study of nearly 18,000 dogs shows that breed explains only about 9% of the behavioural differences between dogs, and that within a single breed, or a single sex, the gaps are huge. Sex brings a few hormone-related tendencies; for the rest, your dog is shaped by their experiences and by the way you raise them.

Male or female: what really changes day to day

You are welcoming your very first dog

Sex is not the right first criterion. Aim above all for a sociable, settled dog who does not get wound up over nothing, male or female. Character differences linked to sex are small and vary hugely from one dog to the next.
The real criterion is the individual dog in front of you. At a rescue centre or at a breeder's, ask to meet them, watch whether they come towards you and how quickly they recover from a surprise. One specific dog will tell you more than any generality about their breed.

You already have a dog at home

Male and female is the easiest pairing to live with; two males or two females is possible, but it calls for more care.
If your current dog is reactive with other dogs, do not take on a second dog before you have sorted that out.

You are hesitating about an unspayed female

Expect two seasons a year, two to three weeks each, with extra vigilance around escapes and accidental matings.
That is no reason to rule out a female: it simply needs planning for, and a conversation with your vet.

Puppy or adult: two adventures, neither one better

With a puppy, everything is still to be built: house-training, being left alone, discovering the world, and energy that spills over everywhere. With an adult, often from a rescue centre, you can already see who they are, sometimes with a few basics in place, and you skip the hardest phase. Yet "adult means already trained" remains a myth: many arrive with no basics at all, though a dog can learn at any age.

A puppy will suit you if…

You can be around for several weeks when they arrive, for house-training and the first routines.
You have the energy for very frequent outings and for socialisation that starts on day one.
You accept that house-training takes weeks, not days.

An adult is for you if…

You want a character that is already there (energy, sociability) rather than a blank page.
You would rather skip the puppy phase, intense and physical: rescue centres are full of wonderful adults.
You accept starting again from scratch, "like a puppy", while you find out what they already know.

In France, a puppy cannot be separated from their mother or sold before 8 weeks (2 months): those weeks with mother and littermates are decisive for their balance. A puppy offered younger, "available right away" and without papers, is a red flag.

Morrill et al. — Ancestry-inclusive dog genomics challenges popular breed stereotypes (Science) (2022)
Hart et al. — Assisting Decision-Making on Age of Neutering for 35 Breeds of Dogs (Frontiers in Veterinary Science) (2020)
Transfer of a pet animal: minimum age of 8 weeks, commitment certificate and cooling-off period, Service-public.fr / Code rural

Keep going

guideWhich dog is right for me?Even before sex or age, this guide helps you pin down the dog that fits your lifestyle.Read the guide guideShelter, private seller or breeder: where to adopt?Once the profile is clear, you still need the right front door: rescue centre, animal charity, private seller or breeder.Read the guide guideSpaying or neutering your dogSex matters less than you think: spaying or neutering weighs far more on their health and behaviour. Here is how to decide.Read the guide guideChoosing to adopt an adult dog (shelter or rescue)Leaning towards an adult rather than a puppy? This guide walks you through that adoption.Read the guide guideGetting ready for your puppy's arrivalGoing for a puppy instead? Everything you need to get the house ready before they arrive.Read the guide guideSize, coat, energyLike sex and age, breed alone does not tell the whole story: learn to read the real traits behind the label.Read the guide

Frequently asked questions

Should I get a male or a female dog?

Neither one as a matter of principle: character depends mostly on the individual dog and on their upbringing, not on sex. Aim for a sociable dog who fits your lifestyle, male or female. If you already have a dog, a male and female pairing is the easiest to live with.

How do I choose between a male and a female dog?

Look first at the individual dog (sociability, energy, tendency to get wound up) rather than the sex label. With an unspayed female, plan for two seasons a year. Spaying or neutering is decided with your vet, for health reasons, not to "control" a behaviour.

What age should I adopt a dog at?

For a puppy, never before 8 weeks (2 months): that is the legal minimum age in France, and those weeks with their mother are decisive for their balance. An adult dog, on the other hand, can be adopted at any age, and training stays possible for life.

Puppy or adult dog: which one should I choose?

With a puppy, everything is still to be built (house-training, being left alone, socialisation) and there is a lot of energy: plan for several weeks at home when they arrive. An adult gives you a character that is already in place and lets you skip the most physical phase. Neither is better, one simply fits your life better.

Is an adult rescue dog already trained?

Not necessarily: "adult means already trained" is a myth, and many arrive with no basics at all. The good news is that a dog can learn at any age. You pick things up gently, "like a puppy", to find out what they already know and help them with the rest.

Male or female for a second dog?

Male and female is the easiest combination; two males or two females is possible but trickier. Above all: if your first dog is reactive with other dogs, do not take on a second one before sorting that out with a trainer.

Updated on July 11, 2026Sources

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