Dogs can see blue, yellow, and grey, but not red and green.
Dogs have been domesticated for over 10,000 years.
A puppy will go through infancy, childhood, and adolescence in about one year.
When a dog flicks his tongue repeatedly, it usually means he's uncertain.
Dogs stick their heads out car windows to feel and smell the wind against their faces.
There are more than 200 million scent-receiving cells in a dog's nose.
Dogs will never wag their tails without another living being there to see it.
A dogs' average body temperature is about 4°F higher than a human's.
Dogs have been proven to respond to more than 60 words.
It's a myth that touching your dog's nose can tell you whether he's healthy.
Dogs use up to 30% of their daily protein requirement to maintain a healthy hair coat.
Dogs view their families as a pack, and are happiest when they're the lowest of the pack.
The best time of day for dogs to track a smell is in the morning.
Dogs can live for weeks with little food, but will die without water within a few days.
Dogs can hear a sound 250 yards away—that's over two football fields!
Chocolate is toxic for dogs because they can't metabolize theobromine.
Dogs are omnivores. That's why they have flat molars for grinding vegetation.
A typical human skeleton has 206 bones, but a domestic dog's has about 321.
A puppy's "milk" teeth come in at three to five weeks of age.
By two years old, puppies will increase their birth weight by 40-50 times.
Onions can cause hemolytic anemia, a condition that destroys a dog's blood cells.
There are more than 500 breeds of dogs in the world.
A puppy's eyes remain closed for the first seven to ten days of life.
80% of a puppy's body weight and 50-60% of an adult dog's body weight is water.
You can winterize your dog's dry skin by using moisturizer and a humidifier.
Cats can see blue, yellow, and grey, but not red and green.
Some experts say a cat's purr can help her bones when she's had an injury.
Purring sounds come from two membrane folds behind a cat's vocal chords.
Some cats put their toys in their water or food dish to mark "their territory."
Road engineers have copied the startling reflection of a cat's eye for highway markings.
The pad behind a cat's leg, called a "carpal pad," protects her from crash landings.
Cats can't be vegetarian—they desperately need specific nutrients found only in meat.
Cats rarely meow for other cats; it's believed to be a learned response.
A normal kitten's weight practically triples during her first three weeks.
On average, outdoor cats live about 8 years while indoor cats live 14 or more.
If your cat is three years old in "people years" she's 23 years old in "cat years."
Cats have been domesticated since at least 1600 BC.
Descended from desert animals, cats don't have a strong drive to drink water.
Cats are the only mammals unable to taste sweetness.
A cat's nose is ridged in a unique pattern, much like a human fingerprint.
Some cats are more responsive to feminine voices with high sound frequencies.
Cats prefer to eat up to 23 small meals a day consisting of about 25 calories each.
A human's average body temperature is 98.6°F and a cat's ranges from of 101°F - 102.2°F.
Cats can produce roughly 100 vocal sounds, versus a dog's limited vocabulary of 10 sounds.
Dog food isn't necessarily suited for a cat's nutritional requirements, and vice versa.
Cats spend an estimated 1/3 of their waking hours grooming themselves.
A blindfolded cat can orient herself just by using input from her whiskers.
A cat's hearing is about two octaves higher than yours, up to 60 or 70 kHz.
When a cat wags her tail, it often means she's contemplating a decision.
Cats use special glands on their lips, chin and tail to mark objects with their scent.
Many cats are lactose intolerant, which means cow's milk will give them a bellyache.
In semi-darkness, cats' eyes can scoop up even the smallest scrap of available light.
Most cats dislike the smell of vinegar, onions, and strong citrus scents.
Cats can only sweat through their paws.
Cats are extremely flexible; they have twice as many spinal vertebrae as humans.
A cat's third eyelid slides over her eye to protect the surface.
Cats don't need added Vitamin C in their diets.
50% of a cat's immune system is found in the digestive tract.
Cats can build up a tolerance to catnip.
While canine memory lasts no more than 5 minutes, a cat's recall can last as long as 16 hours.
Cats "knead" to show pleasure or contentment.
Cats place each hind paw directly in the print of their forepaws when they walk.
A domestic cat's sense of smell is about fourteen times as strong as a human's.
Cats groom themselves more in warm weather because saliva acts as a cooling mechanism.
The longest living cat on record lived until her 36th birthday.