Do large dogs have larger brains and higher intelligence levels than small dogs?

There is a huge amount of variation in terms of the physical size and appearance of different dog breeds, and obviously, smaller dogs have smaller heads and skulls than their bigger cousins! Each and every breed of dog has specific traits and aptitudes too, due to a combination of their natural path of evolution, and the tasks that they were bred and trained to do by man. Intelligence levels can vary greatly from dog to dog, and looking at it objectively, it is easy to see why you might assume that a larger dog, with a larger brain, may be more intelligent than a tiny little dog.

But is there any truth in this assumption, and are larger dogs actually smarter than small ones? Read on to find out more!

Brain size and variation

The differences between the size of the brain of different dogs come about due to the size of the body and frame, and so a smaller dog will naturally have a physically smaller brain than a large dog. However, in order to accurately measure the size of the brain of any animal, you have to take brain size in relation to the proportion of the build, rather than as a simple sum of the weight and physical mass of the brain.

This means that in terms of proportion of brain size to body size, as dogs get smaller, their brains are actually proportionally much larger compared to their body weight than most large dog breeds.

The size of the brain and its relation to canine intelligence

When you take into account the equation of the size of the brain compared to the size of the body, you might then take the natural path to concluding that the larger the brain proportionate to the body, the brighter the dog will be.

However, the size of the brain itself and the size relative to the body does not dictate canine intelligence, and there is no linear progression that you can follow in terms of brain size being directly related to intelligence in the dog. Taking the metaphor of the brain as a computer, Professor Lars Chittka, speaking in “Science Daily” magazine, said that a large brain might mean a bigger “hard drive,” but that this does not mean it also has better or faster processors than a smaller brain.

Selective breeding and intelligence

Over the history of man’s involvement with the selective breeding of dogs, our input into the evolution of dog breeds has also led to other changes, such as the shape, size and structure of the skull of some breeds, and ergo, the structure of their brains too.

One of the best understood examples of this comes in dogs that are brachycephalic, or that have short, squat muzzles. In dogs of these types, the olfactory lobes of the brain are located near to the base of the skull at the back of the head, while for longer nosed breeds, these lobes are located at the front. Selective breeding for the breed trait of a shortened muzzle has caused this significant change in the position of the lobes, however, the lobes remain the same size and perform the same function across all of the breeds, regardless of position!

Intelligent dog breeds

In the Coren listing of canine intelligence, which ranks the main hundred or so dog breeds from top to bottom in order of intelligence, the dogs that make up the top twenty or so members on the list have very little in common in terms of their size and build. Both small, medium and large dogs rub shoulders across every part of the list, indicating that there really is no brain or head size rule when it comes to measuring canine intelligence.

It is also worth noting that intelligence is not a one size fits all question, and just as with people, dogs can manifest intelligence in a whole range of different ways. Some dogs will be incredibly amenable to training and have an excellent memory, such as the Border Collie, at the top of the canine intelligence rankings. However, other dogs that fall further down the list will also display their own unique talents, such as a superior hunting prowess or greatly heightened sense of smell and ability to scent and track.

Ultimately, how you view canine intelligence and what you class as the manifestation of intelligence will vary from case to case, but brain size and body size are responsible for very little, or possibly even no part of the intelligence of the dog.

When it comes to canine brain size and how smart your dog is, it really is a matter of what they do with their brains, rather than how large their brains are that counts, and even for the smallest of dogs, a large proportion of their mental abilities will lay dormant or unused at any given time.