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  • Regardless of whether you own a pet that barks or purrs, you still have probably heard a myth or two about them. Here are some truths, facts and falsehoods about the top 11 most common myths about dogs and cats.

    Image: A one-year-old white Sapsaree named Sulhee plays in Gyeongsan
    Hyungwon Kang  /  Reuters file
    When a dog wags its tail, does it mean it's happy? Sometimes it does and sometimes it doesn't.
  • 1. Dogs are color blind

    The origin: The basis for this myth is not known.

    The truth: Dogs do see in color. However, they see differently than most people do and are less able to distinguish between colors. Veterinary ophthalmologists have determined that dogs see like people who have red/green color blindness. Dogs’ eyes have receptors for blue and green shades, but not for red shades. As a result, it appears that dogs cannot easily distinguish between yellow, green and red, but they can identify different shades of blue, purple and gray. Color is only one of many visual stimuli that dogs detect in their environment. Brightness, contrast, and especially motion, are extremely important to a dog’s interpretation of what it sees.

  • 2. Cats always land on their feet

    The origin: In the feline world, the most popular cliche is, "Cats always land on their feet." In reality, although cats do instinctively try to fall feet first, they commonly break bones or suffer other injury when falling from heights.

    The truth: This is perhaps one of the most widely known and dangerous of all myths regarding cats, because unfortunately many children have tried to prove that it is true. It is not. Cats are indeed very athletic and agile animals, and they do have a unique instinctive ability to twist themselves around in mid-air to correct their position during a fall. However, if a cat is surprised, sick, disoriented or injured, it is unlikely to be able to adjust its position to land feet-first. Of course, if it falls from a great height, a cat’s ability to reposition itself will not matter, because the force of the fall will cause serious injury or even death whether the cat’s feet hit the ground first or not. Moreover, if a cat falls from a short height, it may not have enough time to twist around and land on its feet.

  • 3. If a dog's nose is warm, it means it's sick

    The origin: There is no identifiable origin for this myth. People just seem to think that a dog with a warm and/or dry nose is sick, and that a dog with a cold wet nose is well.

    The truth: If a dog has a dry or warm nose, it means that he has a dry or warm nose. A dry nose or a mildly warm nose has nothing to do with the overall health of a dog.

  • 4. If a dog is wagging its tail, it is happy

    The origin: Most dogs do wag their tails when they are happy. As a result, people associate a wagging tail with a happy dog.

    The truth: In many cases, a dog that is wagging its tail is happy, or at least is expressing excitement or pleasure. Tail-wagging certainly does express a strong state of emotion, much like a smile does in people. However, just like a human smile, a dog’s wagging tail does not necessarily reflect happiness or something positive. Dogs frequently wag their tails when they are agitated, irritated, tense, anxious, annoyed, frightened, angry or aggressive. Interestingly, researchers have found that dogs do not normally wag their tails when they are alone, even if they apparently are happy or are in a pleasant situation. Tail-wagging seems to be a behavior that is reserved for times when the dog is in the company of others.

  • 5. Cats have nine lives

    The origin: This myth probably stems from the fact that cats are very supple and resilient animals, even when they are ill or injured. Cats have a keen ability to get out of situations that would probably be the death of lesser animals. There are many reports of cats surviving for lengthy periods of time in very harsh conditions, even without easily accessible food or water. The related myth that cats always land on their feet may also contribute to the myth that cats have nine lives. Nine is considered by many to be a lucky number. In some cultures, the myth is that cats have seven lives. Either way, cats are considered to be lucky.

    The truth: Of course, cats do not “have nine lives.” Cats are mortal. However, they do tend to be very healthy, hearty animals that can take care of themselves in most any situation, whether indoors or out. They are nimble, intelligent and resourceful. But, like all other mammals, cats only have one life to live.

  • 6. A dog's mouth is cleaner than a human's mouth

    The origin: Dog saliva was once believed to be antiseptic, and some people still believe it has healing properties. The basis for this belief is not known.

    The truth: A dog’s mouth is not “cleaner” than a person’s mouth. Dog saliva can be toxic to some bacteria, but it carries its own population of bacteria and other infectious organisms. That population is just different from the assortment of bacteria and other “germs” in the human mouth, based largely upon differences in diet. There is a reason for the term, “dog breath.” People with weakened immune systems and young children probably should not have direct contact with dog or cat saliva.

  • 7. One year of a dog's life is equal to 7 years of a human's life

    The origin: The basis for this myth remains a mystery. It probably comes from simple math: an average life span for dogs is 10 to 12 years, and multiplying this by seven equals 70 to 74 years, roughly the average life span for people today.

    The truth: Contrary to popular belief, there is no exact formula to gauge how much a dog develops or ages in comparison to so-called “people years.” Aging is as individual for dogs as it is for people. Taking a dog’s age and multiplying it by 7 is an overly simplistic formula and does not reflect a dog’s actual developmental status. A more accurate rough guide is as follows:

    • 1-year-old-dog equals a 15-year-old human
    • 2-year-old-dog equals a 24-year-old human
    • 4-year-old-dog equals a 32-year-old human
    • 7-year-old-dog equals a 45-year-old human
    • 10-year-old-dog equals a 56-year-old human
    • 15-year-old-dog equals a 76-year-old human
    • 20-year-old-dog equals a 98-year-old human

    Of course, there is a distinct difference in aging between small dogs and giant breed dogs. Large dogs have a significantly shorter life span than do small dogs. Their development in the early years is about the same as other breeds; however, large and giant breed dogs developmentally are much older than smaller breeds in their later years, starting at about 7 years of age.

  • 8. You can't teach an old dog new tricks

    The origin: This myth probably started with someone who wasn’t able to get his older dog to sit, roll over, come or stay. It is one of the most common (albeit false) clichés about domestic dogs.

    The truth: You can teach an old dog new tricks. Dogs can learn new tricks, skills and commands within their physical capabilities until the day they pass away. What’s more, they usually want to learn. Their minds need stimulation, just like ours. With patience, kindness, persistence and consistency, owners can teach their older dogs all sorts of new tricks, such as sit, bark when the doorbell rings, fetch, lie down, roll over, play dead and shake or “high five.” As long as a dog is bright, alert, responsive and healthy, there is no reason that he cannot keep learning new things throughout his life.

  • 9. Cats purr because they are happy

    The origin: This myth, like many others, doesn’t have a precise origin. It probably comes from the fact that most cats do purr in the presence of their owners when they are being petted, which we interpret as a sign of happiness.

    The truth: Most cats do purr when they are happy. However, that is not the only time they purr. Cats will sometimes purr when they are sick, stressed, injured, frightened or in pain. They also can purr when they are giving birth, and even as they are dying. Purring seems to be more an expression of some strong emotion - whether positive or negative - than it is an expression of any particular emotion, including happiness. Purring by a cat might be similar to humming or whistling by a human: it commonly is done out of happiness, but it may also be done as a result of stress, fright or discomfort.

  • 10. Cats can see in the dark

    The origin: This myth probably originates from people observing cats navigating at night. Cats are often active at night and do tend to get around very well in the dark.

    The truth: Although cats do see better in semi-darkness than people, they cannot see in total darkness. The pupils of their eyes open much wider in dim light than those of people, letting in more light during the normal hunting hours of dawn and dusk. But again, cats cannot see in complete darkness.

  • 11. Dogs eat grass to throw up

    The origin: This myth originates from people observing their dogs eating grass and then vomiting.

    The truth: There actually appear to be two distinct types of grass-eating behavior in domestic dogs. Some dogs graze casually, taking only a few nibbles of grass at a time, while others chow down on grass vigorously and with a purpose. Dogs who wolf down their grass tend to vomit it (and other stomach contents) within a matter of minutes. Dogs that graze slowly usually do not throw up. So, eating grass does not necessarily mean that a dog has an upset stomach.

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