Animal Comparison
Cat vs Dog
Cats (Felis catus) are small obligate carnivores of one fairly uniform size; dogs (Canis familiaris) are pack-descended omnivores ranging from 1.5kg to 90kg. Full comparison.
By the WARN Research & Conservation TeamChecked against IUCN Red List & CITES sourcesLast updated
In brief — Cat vs Dog
Cats are small obligate carnivores of one fairly uniform size; dogs are pack-descended omnivores bred into vastly varied sizes. Different species, different families, both long-domesticated companions.
The clearest difference is diet and body plan: the cat (Felis catus) is a small, solitary obligate carnivore that must eat meat and comes in one fairly uniform size (usually 2.7-4.5 kg), while the dog (Canis familiaris) is a pack-descended, adaptable omnivore selectively bred into an enormous range of shapes and sizes, from a 1.5 kg Chihuahua to a 90 kg mastiff. They are different species in different families and are not close relatives.
See the difference
Cat — small obligate carnivore of fairly uniform size
Image: WARN wildlife library
Dog — pack-descended omnivore, hugely varied in size
Photo: Jakub Hałun / Wikimedia Commons (CC BY-SA 4.0)
Cat vs Dog: At a Glance
| Feature | Cat | Dog |
|---|---|---|
| Scientific name | Felis catus | Canis familiaris (Canis lupus familiaris) |
| Family | Felidae (cats) | Canidae (dogs, wolves, foxes) |
| Wild ancestor | African wildcat (Felis lybica) | Grey wolf (Canis lupus) |
| Typical weight | 2.7-4.5 kg (6-10 lb) | 1.5-90 kg, depending on breed |
| Adult teeth | 30 | 42 |
| Diet | Obligate carnivore (must eat meat) | Omnivore (eats meat and plants) |
| Top sprint speed | Up to ~48 km/h (30 mph) | Up to ~72 km/h (45 mph) in greyhounds |
| Typical lifespan | 13-17 years | 10-13 years (larger breeds shorter) |
| Social structure | Largely solitary hunter | Pack-oriented, cooperative |
| Domesticated | ~10,000 years ago, Near East | At least 15,000 years ago |
| World population | Roughly 600 million+ | Roughly 900 million |
| Conservation status | Domestic; not a threatened species | Domestic; not a threatened species |
Which is bigger & stronger?
The largest dogs are far bigger and stronger: a typical cat weighs 2.7-4.5 kg, while dogs span roughly 1.5 kg to 90 kg, so a big dog can outweigh a cat roughly twentyfold.
Cats and dogs are the two most popular companion animals on Earth, yet they are only distantly related: both belong to the order Carnivora, but the cat sits in the family Felidae and the dog in the family Canidae, lineages that diverged tens of millions of years ago. The dog (Canis familiaris) was the first animal humans domesticated, appearing in the archaeological record at least 15,000 years ago, descended from the grey wolf. The cat (Felis catus) followed much later, domesticating itself in the Near East around 10,000 years ago as wildcats moved into early farming settlements. Those separate origins, one a cooperative pack hunter, the other a solitary ambush predator, still shape almost every difference between them today, from diet and dentition to temperament and trainability.
Size and strength
This is where the two split most dramatically. Cats are strikingly uniform: almost all pet cats weigh between 2.7 and 4.5 kg (6-10 lb), with a head-and-body length around 46 cm and males a little larger than females. Dogs, reshaped by thousands of years of selective breeding, span an extreme range, from a 1.5 kg Chihuahua to giant breeds such as the Great Dane or mastiff at 45-90 kg. So while a cat and a small terrier are comparable, the biggest dogs outweigh a cat roughly twentyfold and are far stronger.
Diet and teeth
Cats are obligate carnivores: they must eat animal tissue to obtain nutrients such as taurine and cannot thrive on a plant-based diet. Their 30 teeth are built almost entirely for gripping and slicing meat, with prominent canines and blade-like carnassials but few grinding surfaces. Dogs are far more flexible omnivores; although descended from wolves, they evolved alongside humans to digest starches and can live on a varied diet. Their mouth holds 42 teeth, including more premolars and molars suited to crushing and chewing a broader range of foods.
Behaviour and trainability
The dog descends from a cooperative pack hunter, and that legacy makes most dogs sociable, hierarchy-aware and highly responsive to training, which is why they work as guides, herders and detection animals. The cat descends from a solitary ambush predator, so it is more independent, territorial and self-directed. Cats can be trained but are less driven to please, hunt alone rather than in groups, and communicate largely through scent, posture and a wide vocal range, including the purr, that dogs do not share.
Range, habitat and lifespan
Both animals now live almost everywhere humans do, on every inhabited continent, as pets, working animals and free-roaming strays. Cats tend to keep smaller home territories and are agile climbers; dogs range more widely and travel further on foot. On lifespan, cats generally live a little longer, commonly 13-17 years and occasionally past 20, while dogs typically reach 10-13 years, with a strong pattern of large breeds ageing faster and dying younger than small ones.
Are they the same animal?
No, and they are not even close relatives. Cats and dogs are separate species in separate families, Felidae and Canidae, which last shared a common ancestor tens of millions of years ago. They cannot interbreed, have different numbers of teeth and chromosomes, and were domesticated separately from different wild ancestors, the African wildcat and the grey wolf. The idea that they are variations on one animal is a common misconception.
Did you know?
Cats domesticated themselves: rather than being deliberately tamed like dogs, wildcats moved into the first farming villages of the Near East around 10,000 years ago to hunt the rodents drawn to stored grain, and the tamest simply stayed, striking up a partnership with humans on their own terms.
Cat vs Dog: FAQs
Which is bigger, a cat or a dog?
Can a cat beat a dog in a fight?
Are cats and dogs the same animal?
How can you tell a cat from a dog?
Which lives longer, cats or dogs?
Are cats or dogs more common in the world?
Why can dogs eat more foods than cats?
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