Dogs experience the world differently from people. Their senses and ways of learning help explain familiar behaviors. Here are ten facts explained.

1. A nose has a detailed surface pattern

The grooves and ridges on a dog's nose form a distinctive pattern. However, a nose photograph should not replace a microchip, identification tag and current contact details when planning how to recover a lost pet.

2. Dogs do sweat

Sweat glands in the paw pads produce moisture, but panting is a major way dogs release heat. Their normal body temperature is generally higher than ours. A warm nose does not measure fever, and no dog should be left in a parked car while an owner relies on an open window to keep it cool.

3. Dim-light vision has advantages

Dogs have many light-sensitive rod cells and a reflective layer behind the retina that helps them use available light. They often detect movement well in dim conditions, but they cannot see in complete darkness.

4. Smell and hearing matter enormously

A dog's sense of smell is highly developed, and dogs can hear higher-frequency sounds than people. Exact performance varies with the task and individual. Claims that all dogs smell a fixed number of times better than humans oversimplify a complex sense.

5. Puppies and adults have different teeth

A typical puppy has 28 baby teeth, while a typical adult has 42 permanent teeth. Missing, retained or damaged teeth can change that count. Introduce gentle toothbrushing and have dental concerns checked rather than assuming chewing toys provide complete dental care.

6. Sleep includes active phases

Dogs experience rapid-eye-movement sleep, and paws or facial muscles may twitch while they rest. This is consistent with dreaming, although we cannot know the contents of an individual dream. Let a sleeping dog rest instead of startling it awake.

7. Heart rate is not one fixed number

Size, age, fitness, excitement and health all affect pulse. A puppy's heartbeat may be faster than a relaxed adult's. A single number from a fact list cannot diagnose illness; weakness, collapse or difficult breathing requires veterinary attention.

8. Smell helps make food appealing

Dogs have fewer taste buds than humans, yet food scent is very important to them. Eagerness to eat a food does not make it nutritionally balanced or safe. Choose a complete diet appropriate to the dog's life stage.

9. Dogs see colors

Dogs are not limited to black and white. Their two types of color-sensitive cone cells give them a different color range, with blue and yellow easier to distinguish than red and green. Contrast and movement also help them locate a toy.

10. Learning differs between individuals

Dogs can learn words, gestures and routines, but there is no universal vocabulary limit or human-age equivalent. Clear cues, timely rewards and practice in different settings help. Train the dog in front of you rather than expecting it to match a record-setting performer.