For every fact about dogs out there, there's a litter of dog myths running around. So, when someone tells you something about your pet, how do you know what to believe? Here's a list of the five most common misconceptions related to our furry friends.

1. Dogs See in Black, White and Gray

One of the most common dog myths is that dogs are colorblind. They can see some color, but the spectrum is limited compared to human color vision, says the American Kennel Club. This is because our canine pals are dichromatic, meaning their eyes only have two kinds of the cone cells that control color perception. Humans and most other primates have three kinds of cones, making us trichromatic. For an approximation of how your dog sees the world (similar to a person with red-green color blindness, scientists think) you can check out the Dog Vision online tool. That orange squeaky toy just might look blue to your pooch!

2. Dogs Age in Human Years

While dogs comparatively age much faster than humans, one of the common misconceptions about dogs is that in one year of their life equals exactly seven human years. This fuzzy formula would mean a ten-year-old dog is comparable to a seventy-year-old human. According to Priceonomics, this myth has been around since at least the thirteenth century! Your pup grows up and ages very quickly, but the rule of seven (or three for cats) isn't precise. What truly affects your dog's age in human years is his size, breed and genetic makeup. Wondering how old your dog is right now compared to your brother or grandpa? Pet Health Network® has a great chart based on weight and age to help you figure out how your pooch ages over time.

3. Dogs with Warm, Dry Noses Are Sick

It's often believed that a healthy dog has a cold, wet nose. However, warm or dry noses are completely normal for dogs and shouldn't be taken as a sign you should worry about your pet's health. Petful writes that everything from dry air to allergies to simply taking a nap can affect the wetness of your dog's nose. However, while nose health isn't normally concerning, if you notice your pet's nose is constantly dry, cracking or running (not simply wet), make an appointment with your veterinarian.

4. Dogs Have Clean Mouths

Yuck. Of all the dog myths you hear, don't believe this one. Dogs explore their world with their mouths and noses, and because of that, there's no telling what's been in your pet's mouth that very day. (Remember, some dogs enjoy eating their own poop.) If dental hygiene is important to you, commit to a daily teeth-brushing routine. As far as getting sick from a doggy kiss, the New York Times reports that the germs in your dog's mouth are typically specific to dogs. Some pathogens like salmonella and certain rare bacteria strains can be passed on to humans in dog saliva, but serious infections are relatively rare. So don't stress too much over the occasional lick.

5. Dogs Wag Their Tails When They're Happy

Think your pup is showing you how pleased he is that you're home when he slaps his tail from side to side? You may be right, but a wag represents a lot more than happiness. A wagging tail can also be a sign of anxiety, frustration, or nervousness, says PawCulture. So how do you know whether your dog is happy or apprehensive when he sees you? Pay attention to his overall body language. Pet Health Network suggests looking at a dog's stance, the position of his ears and the look in his eyes before you approach him.

6. Dogs Should Eat Like Wolves

While it is true that dogs and wolves share a genetic ancestral line, dogs and wolves are from the same animal. Dogs have evolved over thousands of years from strict carnivores that wolves are, to be omnivores — meaning that a raw meat-based meal can actually have very negative health consequences for your dog. In addition, to being a domicile pet rather than a wild beast of the forest, wolves tend to only live around six years — much shorter than dogs, of which proper nutrition has been shown to play a role. So, don't buy the hype when pet food companies tell you to feed your dog a "wolf-like" diet; rather look for one that is balanced with a dog's specific biologic makeup in mind.