We all wish we could just talk to our dogs and ask them how they're feeling - but unfortunately we can't, so we need to find other ways to understand their emotions.
Canine behaviourist and trainer, Adem Fehmi, from Barking Heads, says it's all in the body language and knowing your pet's patterns of behaviour.
From posture to tail position and eye contact, Adem lets us in on how dogs express themselves - so we'll always be able to spot the tell-sale signs that they are happy or sad.
He told The Mirror : "Dogs are social mammals and, like us, communicate their needs and emotions in a variety of ways.
"Our dogs obviously cannot speak, so they rely heavily on their body language, actions and vocals to communicate both positive and negative needs or emotions.
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"As owners, it is important that we take the time to understand our individual 'dog's language' and help them to navigate our modern world with as little stress as possible, whilst also fulfilling their needs and keeping them happy and content."
Adem explains common signs that a dog is not comfortable or perhaps fearful and anxious include: trying to avoid physical contact, displaying whale eye (where you can see the whites of the eye), lip licking, yawning, heavy panting, lip curling, growling or even attempting to bite.
Body posture
If your dog has a relaxed body posture, it's a sign they are feeling happy. But if their head position is low and their ears are back, it's likely they're worried and uncomfortable.
Adem said: "The main way in which dogs communicate with us is through their body language. You should be able to see if they look relaxed or tense as an overall indicator of their emotions. This is a good starting point."
Tail
In the same way that tears don't always mean we're sad, a wagging tail doesn't always mean your dog is happy.
But generally, a tucked tail indicates your dog is feeling sad or scared.
Adem explained: "Tails can be tricky to read if you don’t know what you’re looking at. Whilst a tail between their legs signifies that a dog is maybe unsure, anxious, or worried, a wagging tail could indicate happiness but also be a sign of uncertainty, fear, or submission to name a few."
Getting to know your dog's tail and observing their reaction to things like treats and training can help.
Eye contact
If your dog is avoiding eye contact with you, it's likely they are worried or nervous.
If they are staring at you and expressing other typical signs of happiness, such as a wagging tail, it's likely they want attention.
Adem said: "Some dogs may stare at an owner to instigate play, affection or even perhaps being fed. Others however may stare fearfully as a sign that they do not want to be approached or touched.
"It is important to consider a dog's body language, rather than one indicator to gain a true reflection of their overall happiness and needs."
Adem says some breeds can be easier to read than others and display clearer body language, such as collies and Labradors.
Others are slightly harder to understand due to their physiology, for example some short snouted and tailed breeds.
He added: "It is important to know your individual dog, and if you are unsure, a certified behaviourist will be able to assist."
Do you have a dog story to tell? Contact nia.dalton@reachplc.com.