What are the main differences between cats and dogs that we don't know?
The cat (Felis silvestris catus) is a collective name for the smaller members of the cat family (Felidae), but usually refers to the domestic cat (Felis silvestris catus), a subspecies descended from the wildcat.
In North America and Europe there are more pet cats than dogs – over 175 million. The first domestic cat appeared 6,000 years ago. The cat's history is best documented in Ancient Egypt, where cats were used to protect stored grain from mice and other rodents.
Domestic cats are among the finest predators. This is backed up by a number of anatomical features.
Teeth and jaw
Kittens are born with 26 needle-sharp teeth. By 6 months of age, these are replaced by 30 permanent ones. Unlike a dog's, which eats a more varied diet, a cat's jaw has more limited movement.
Skull
Cats' eyes are fully adapted for hunting. A cat's pupil can dilate by up to 90%, letting the maximum amount of light into the eye and improving night vision. The pupil also widens when a cat is frightened.
Limbs
Cats have claws designed for gripping and holding onto prey, while a dog's claws play a secondary role.
Feeding
Cats also have certain physiological and metabolic features typical of true predators. Their metabolism is characterised by unusually high protein needs (25%) compared with dogs' needs (17%). This increased protein requirement isn't down to a greater need for any particular amino acid, but to high enzyme activity in the liver. The activity of these enzymes can't be regulated if the protein content of the food is low. Cats are extremely sensitive to a deficiency of the amino acid arginine. Affected animals show acute signs of poisoning and can die.
Taurine is a beta-amino sulfonic acid that must be present in cats' food, since unlike other species, they can't synthesise it themselves. Chronic taurine deficiency causes blindness, reduced reproductive ability, developmental abnormalities in kittens and heart damage. Plant-based foods are low in taurine, so cats shouldn't be fed mainly on them.
Did you know why cats and dogs need different amounts of water? Cats' ancestors lived in the deserts of North Africa and adapted to that environment.
That's why domestic cats produce much more concentrated urine than dogs and can survive on less water. This, however, makes them more prone to forming urinary stones. If we feed our cat a typical ready-made dry food, they'll drink 1.5–2 ml of water per gram of dry food, a ratio of 2:1. If we feed them wet food instead, they'll drink far less water.
Regardless of how much food they eat or how little water they need, we should always make sure they have access to their water bowl.
