I want to start with a confession.

A few winters ago, I stood in a pet shop for approximately twenty-five minutes holding a $179 quilted dog jacket in one hand and my Border Collie, Bob, sitting beside me, while Bob stared at me with the specific expression dogs reserve for moments when they have correctly diagnosed their owner as being unhinged.

I bought the jacket.

Bob wore it once, on a walk during which he shook himself violently approximately every forty seconds in an attempt to remove it, and then sat down in a puddle with the deliberate energy of a creature who has decided to ruin something. I took it off, carried it home in my other hand, and never spoke of it again.

The jacket currently lives in the cupboard under the stairs, next to a collection of other well-intentioned dog purchases that Bob and I disagreed about.

So I come to this topic not as a detached observer but as someone with skin – and $179 – in the game.

The science: are dogs actually cold?

The answer, it turns out, is both simpler and more nuanced than either camp in the great dog coat debate tends to acknowledge.

Dogs do feel cold. They are not, as some people assume, equipped with some magical biological system that renders temperature irrelevant. But – and this is the part that matters – different dogs experience cold very differently, and the gap between a dog who genuinely needs a coat and a dog whose owner needs the dog to wear a coat is wider than the pet fashion industry would have you believe.

The key factors are breed, size, age, body composition and coat type.

A Siberian Husky or an Alaskan Malamute, bred to work in temperatures that would hospitalise most humans, has a dense double coat with an insulating undercoat specifically evolved for cold conditions. Dressing a Husky in a winter jacket is not protecting it from the cold. It is making the dog hot and the owner feel better about themselves.

A Greyhound, however, is a completely different proposition. Greyhounds have almost no body fat, a very fine single-layer coat and a skeletal build that means they lose body heat rapidly. They feel the cold quickly and genuinely. The same is true of Whippets, Italian Greyhounds, Miniature Pinschers, Chihuahuas, Dachshunds and most other fine-coated, lean-bodied small breeds. These dogs are not wearing coats because their owners are anthropomorphising them. They are wearing coats because they need them.

Puppies and senior dogs are also more vulnerable to cold regardless of breed – puppies because their thermoregulatory systems are still developing, older dogs because muscle mass, mobility and circulation tend to decrease with age. A 12-year-old Labrador who would have romped happily through a winter morning at age four may now genuinely appreciate some extra warmth.

Body size matters too. Smaller dogs lose heat faster than larger ones – it is simple physics, the surface area to volume ratio that means a small body radiates heat more quickly relative to its mass. A tiny Maltese standing on a cold footpath in July is losing heat through its paws at a rate that a Great Dane simply does not experience.

So when does a dog actually need a coat?

The indicators are less mystical than you might think. Shivering is the obvious one – though worth noting that some dogs shiver from anxiety rather than cold, so context matters. Slowing down on walks, reluctance to go outside, hunching the back, tucking the tail, seeking to return home earlier than usual, curling tightly into a ball – these are all signs a dog is feeling the cold and would benefit from a little help.

A useful rule of thumb used by many veterinarians is this: if you are cold standing outside in a light jacket, a thin-coated or small dog is probably cold too. If you are comfortable in a T-shirt, your dog almost certainly does not need a coat.

The paw question is also worth addressing. Dogs do not lose the majority of their heat through their paws in the way humans lose heat through their heads – that particular piece of folk wisdom has been largely debunked. However, cold footpaths, ice and road salt can irritate and damage paw pads. Dog boots exist for a reason, and that reason is legitimate, even if getting them onto a cooperative dog remains one of life’s great challenges.

What about the $200 jacket specifically?

I want to gently suggest that the price of a dog coat tells you almost nothing about whether it is appropriate for your dog and very little about its thermal effectiveness. A $20 fleece from a discount pet store will warm a cold Whippet just as reliably as a quilted $200 designer number. What you are paying for at the higher end is, largely, aesthetics – which is fine if you enjoy aesthetics, less fine if you have convinced yourself you are making a medically sound investment.

The dogs who most benefit from coats do not care about the branding. They care about warmth and, rather importantly, about being able to move freely and not having the coat flapping against their legs. A well-fitted, practical waterproof fleece that the dog can actually walk in comfortably is worth more than an Instagram-friendly fashion piece that inhibits movement.

Fit matters considerably. A coat that restricts movement at the shoulders, rubs under the armpits or catches in the legs will cause discomfort regardless of how warm it is. Most dogs take some time to adjust to wearing anything – a gradual introduction, starting with short periods indoors, is far less traumatic for the dog than being bundled into a coat at the gate and expected to get on with it.

The honest answer

Some dogs need a coat. Most medium and large dogs with normal coats do not. Small dogs, fine-coated dogs, elderly dogs, very young dogs and dogs who have had recent surgery or illness are the candidates for genuine thermal assistance.

The rest of us – and I include myself here, standing in that pet shop with Bob’s deeply sceptical face looking up at me – are at least partly dressing our dogs for our own benefit. We are cold. We assume they are cold. We find the miniature puffer jacket endearing in a way that makes us feel something uncomplicated and good.

This is not a crime. It is, in fact, quite human.

Just make sure you can tell the difference between the coat your dog needs and the coat that is mainly for you. And if your dog sits in a puddle while wearing it, take it as a review.

Ali Crisp writes about pets and the people who love them.