Dogs are colour blind, they eat grass when they're unwell and our furry friends have wet noses when they're healthy - here are seven myths that every pet owner should know.

Whether you're a seasoned dog parent or you're looking into getting a pooch of your own, many of us will be guilty of buying into at least one or two of these myths.

Vet Dr Ciara Clark is setting the record straight by tackling some of the biggest misconceptions that we have about our pups.

Butternut Box’s in-house Dr Clark has rounded up seven of the most common beliefs and reveals whether there’s actually any truth behind them.

This is why you should never feed chocolate to your dogs

Why do dogs wag their tails?

It's actually a myth that dogs just wag their tails when they're happy or excited.

While a wagging tail can indicate happiness and excitement, it can also mean that a dog is feeling fear, anxiousness or agitation.

Dr Clark explained: “Dogs may not be able to talk, but if we listen, or rather, watch, we learn a lot about what they are trying to communicate to us and to each other.

"Tail position can indicate a number of things from agitation to negotiation, aggression, insecurity to friendliness, excitement, happiness and curiosity.

“Even the direction your dog’s tail is wagging in can be significant. For example, studies reveal that dogs wag their tails to the right when they are happy or confident and to the left when they are frightened.”

Clydebank Post: 7 common dog myths that every owner should know. ( Getty Images)7 common dog myths that every owner should know. ( Getty Images) (Image: Getty Images)

Is a wet nose a sign that your dog is healthy?

It's actually a myth that if your dog's nose is wet it means it's healthy.

The truth of the matter is a wet nose is normal, but that does not mean that a dry nose is abnormal.

“The idea that a healthy dog will always have a cool, wet nose and a sick pup has a warm, dry one is not always true and, actually, a dog’s nose isn’t always a good indicator of how healthy they are," Dr Clark commented.

"Some healthy dogs naturally have dryer noses and, likewise, sick dogs can have wet noses.

"If your dog’s nose is hot and dry, but they’re acting normally, there isn’t a cause for concern as the temperature of a dog’s nose is not an accurate measurement of overall body temperature.

“However, if a dry nose is present alongside other signs of illness such as loss of appetite, the skin around the nose becomes red or cracked or if there is a noticeable thick or discoloured mucus (green or yellow) around the nose then you should consult your dog’s vet.”

Do dogs eat grass when they're unwell?

One of the most common myths out there is that dogs eat grass when they’re feeling unwell but in reality, we still don’t fully understand why dogs eat grass

Dr Clark went on to say: “While eating odd non-food items such as grass may be a sign your dog’s diet is deficient in nutrients, vitamins or minerals, many dogs, with a well-balanced diet and who aren’t nutrient deficient, will still chew on grass.

"A common assumption is that dogs will eat grass in order to relieve an upset stomach or to be sick.

"Some dogs will eat grass and then vomit shortly afterwards, however, studies have shown that less than 25% of dogs will get sick after eating it.

“That said, grass can be a good source of fibre that can help gut movement. Plus, there’s the simple reason that dogs might actually like it. Some enjoy the texture and taste of grass, so will always have a tendency to eat it.”

Can you give your dog a cold and can you get a cold off your dog?

It's not true that you can pass a cold or a virus on to your dog and vice versa.

Dr Clarke said: “The cold virus is usually a rhinovirus and these are specific only to humans. They cannot be passed on to animals in the same way that a virus a dog or cat has cannot be passed on to humans.”

Are dogs colourblind?

Your pup can actually see in shades of yellow, blue and grey so this is also a myth.

“The retina of the eye has two main types of cells, rods to detect light levels and motion, and cones to differentiate colours," Dr Clark explained.

She added: "While humans have three types of cones allowing them to see different colour combinations of red, blue and green, dogs only have two types of cones: blue and yellow.

"While humans see more colours and brighter colours, dogs possess more rods than humans allowing them to see more clearly in low light and identify moving objects

“Dogs are able to perceive different colours, but it might not be the ‘true’ colour of an object.

"This means that dogs won’t necessarily be able to tell the difference between different colour balls they play with, but due to their great sense of smell, they can usually identify their own ball compared to another dog’s while in the park.

"They also have a greater range of peripheral vision than humans do and are better at detecting the smallest of movements at greater distances.”

Do dogs need variety in their diet?

One of the most common myths is that your pooch doesn't need a range of different foods but there are actually a lot of health benefits to them having a varied diet.

Dr Clark commented: “Dogs have fewer taste receptors than humans and can become bored with the smell, flavour and texture of their food.

"Their sense of smell is way more powerful than their taste, so it’s not surprising that dogs focus more on the scent of the food they’re eating.

"This is why dogs can find a varied and freshly cooked diet a lot more appealing. A varied diet is also great for your dog’s gut health and ensuring they are getting a good source of good bacteria which helps with digestion.

Dr Clark also made some suggestions for what you should do if you have a fussy pet.

“Dogs are drawn to novelty when given the choice," she said.

"Instead of kibble, offer more meaty variety, gently heat the food to create a stronger smell or add cooked ingredients or foods like Butternut Box, which include varied fibre-rich ingredients that act as prebiotics - which good bacteria thrive upon.

"This will awaken those sensitive noses and make an old dish more exciting.”

Does dry dog food keep their teeth clean?

Kibble or dry dog food doesn’t prevent dental disease and pet owners need to give their pooches' teeth a good brushing to combat it.

Dr Clark advised: “According to research, there’s nothing better for your dog’s teeth than good old brushing.

"It’s three times better than giving your dog dental chews and proven to be better than dry dog food.

"Brushing your dog’s teeth regularly is key for good dental care, but not always the most practical or possible. If not, combining both brushing and dental chews, like Butternut Box’s Smile Sticks, is a good alternative and can help freshen bad breath.”