Intelligence:
Dogs: Anecdotal evidence and scientific research suggest that dogs have a reasonably high intelligence. This intelligence is expressed differently with different breeds and individuals, however. For example, Border Collies are noted for their ability to learn commands, while other breeds may not be so motivated towards obedience, but instead show their cleverness in devising ways to steal food or escape from a yard.
Cats: They are also intelligent animals, and some can be trained or learn by themselves to manipulate simple mechanisms such as lever-handled doors and flush toilets.
Winner: Unknown. People have been debating this one for hundreds of years. Using a toilete is pretty impressive though...
Sight:
Dogs: Dogs may actually see some color, but not to the extent that humans do. Because the lenses of dogs' eyes are flatter than humans', they cannot see as much detail; on the other hand, their eyes are more sensitive to light and motion than humans' eyes. Some breeds, particularly the best sighthounds, have a field of vision up to 270° (compared to 180° for humans), although broad-headed breeds with their eyes set forward have a much narrower field of vision, as low as 180°
Cats: A cat's vision is superior at night. In very bright light, the slit-like iris closes very narrowly over the eye, reducing the amount of light on the sensitive retina, and improving depth of field. The tapetum and other mechanisms give the cat a minimum light detection threshold up to seven times lower than that of humans.
Average cats have a visual field of view estimated at 200°, versus 180° in humans, with a binocular field narrower than that of humans. As with most predators, their eyes face forward, affording depth perception at the expense of field of view. Instead of the fovea which gives humans sharp central vision, cats have a central band known as the visual streak. Cats can apparently differentiate among colors, especially at close range, but without appreciable subtlety.
Cats have a third eyelid, the nictitating membrane, which is a thin cover that closes from the side and appears when the cat's eyelid opens.
Winner: Although some dogs have a wider field of vision, cats' eyes are generally better suited for hunting prey. Night vision and a third eyelid are pretty damn amazing.
Hearing:
Dogs: Able to detect sounds as low as the 16 to 20 Hz frequency range (compared to 20 to 70 Hz for humans) and as high as 70,000 to 100,000 Hz (compared to 20,000 Hz for humans) and in addition have a degree of ear mobility that helps them to rapidly pinpoint the exact location of a sound. Eighteen or more muscles can tilt, rotate and raise or lower a dog's ear. Additionally, a dog can identify a sound's location much faster than a human can, as well as hear sounds up to four times the distance that humans are able to.
Cats: Humans and cats have a similar range of hearing on the low end of the scale, but cats can hear much higher-pitched sounds. Cats can hear 2 octaves higher than humans, and one-half octave higher than dogs. When listening for something, a cat's ears will swivel in that direction; a cat's ear flaps can independently point backwards as well as forwards and sideways to pinpoint the source of the sound. Cats can judge within three inches (7.5 cm) the location of a sound being made one yard (approximately one meter) away.
Winner: Unclear. Cats hear higher frequences and pinpoint sounds maybe more accurately, but dogs may actually have a farther range. What do you think?
Smell:
Dogs: They have nearly 220 million smell-sensitive cells over an area about the size of a pocket handkerchief (compared to 5 million over an area the size of a postage stamp for humans). Dogs can distinguish two different types of scents when trailing, an air scent from some person or thing that has recently passed by, as well as a ground scent that remains detectable for a much longer period. The characteristics and behavior of these two types of scent trail would seem, after some thought, to be quite different, the air scent being intermittent but perhaps less obscured by competing scents, whereas the ground scent would be relatively permanent with respect to careful and repetitive search by the dog, but would seem to be much more contaminated with other scents. In any event, it is established by those who train tracking dogs that it is impossible to teach the dog how to track any better than it does naturally; the object instead is to motivate it properly, and teach it to maintain focus on a single track and ignore any others that might otherwise seem of greater interest to an untrained dog. An intensive search for a scent, for instance searching a ship for contraband, can actually be very fatiguing for a dog, and the dog must be motivated to continue this hard work for a long period of time.
Cats: A domestic cat's sense of smell is about fourteen times stronger than a human's. Cats have twice as many smell-sensitive cells in their noses as people do. Cats also have a scent organ in the roof of their mouths called the vomeronasal, or Jacobson's, organ. When a cat wrinkles its muzzle, lowers its chin, and lets its tongue hang a bit, it is opening the passage to the vomeronasal.
Winner: Dogs. Dogs are the ultimate smellers. They could probably smell a fart before it happens.
Diet:
Dogs: At present, there is an academic discussion as to whether domestic dogs are omnivores or carnivores. The classification in the Order Carnivora does not necessarily mean that a dog's diet must be restricted to meat. Unlike an obligate carnivore, such as a cat, a dog is not dependent on meat protein in order to fulfill its dietary requirements. Dogs are able to healthily digest a variety of foods including vegetables and grains, and in fact can consume a large proportion of these in their diet. Wild canines not only eat available plants to obtain key amino acids, but may also obtain nutrients from vegetable matter from the stomach contents of their herbivorous prey. Domestic dogs can survive healthily on a reasonable and carefully designed vegetarian diet, particularly if eggs and milk products are included.
In the wild, these diets are typically pursued in the absence of available meat. It has also been noted that extremely stressful conditions, such as the Iditarod race and scientific studies of similar conditions, suggest that high-protein diets including meat help prevent damage to muscle tissue. This research is also true of other mammals.
Cats: The domestic cat can hunt and eat about one thousand species.
Cats have highly specialized teeth and a digestive tract suitable to the digestion of meat. The premolar and first molar together compose the carnassial pair on each side of the mouth, which efficiently functions to shear meat like a pair of scissors. While this is present in canines, it is highly developed in felines. The cat's tongue has sharp spines, or papillae, useful for retaining and ripping flesh from a carcass. These papillae are small backward-facing hooks that contain keratin and assist in their grooming. Unlike most carnivores, cats eat almost no vegetable matter apart from that found in the digestive tracts of their prey. However, some domesticated cats are known to like vegetables. Whereas bears and dogs commonly supplement their diet of meat with fruits, berries, roots, and honey when they can get them, cats feed exclusively on meat, usually freshly killed. Cats, including the great cats, have a genetic anomaly that prevents them from tasting sweetness, which is probably related to their meat-only habits.
Winner: Unclear. Dogs survive on a much broader diet, but the cat has a more advanced digestive system for its diet, including a spiked tongue.
Communication:
Dogs: About 10 distinct vocalizations for dogs.
Cats: Capable of about 100 different vocalizations
Winner: Cats may develop language far greater than our own...
Conclusion: The two predators are hard to compare.
