Your dog's "smile" could actually be a sign of a health issue, according to an expert.

are intelligent animals. Not only can they respond to commands, with dogs, on average, understanding around 89 words. They can also understand and respond to human emotions - though not necessarily with the same depth of understanding that we might have.

This might make you think that dogs can also mimic our facial expressions to show their own emotions, and while that might be true for some emotions, it's definitely not the case for all of them.

If you've ever seen your "grinning" with an open and relaxed mouth, that actually does indicate happiness most of the time. However, if your dog looks like they're "smiling" with their mouth closed, this could mean something very different.

In fact, this expression could be a signal that something is wrong and an early indicator of a health issue.

The meaning behind a closed-mouth smile was shared on after a person posted a video of their Golden Retriever turning to look at them with a "terrifying" smile.

While some commenters were quick to joke that the dog, named Bowie, smiled like the Grinch from the popular Dr Seuss Christmas tale, others pointed out that there might be something wrong with the pooch.

One person said: "My dog does this just before throwing up." Another added: "The smiling could be a sign of nausea."

The information was also shared in a post on the forum Life Pro Tips, where some said: "If your dog looks like it's smiling with its mouth closed, it's probably about to vomit. They look like the f***ing Grinch. It looks adorable like they love you and are smiling at you, and for a moment, you'll believe it. But really, they're about to vomit, and it's probably too late."

Dogs can vomit for many reasons - and not all of them are serious. Alongside the closed-mouth smile, which may happen just before your dog is sick, you may spot the following signs:

• Lip licking and swallowing
• Dribbling more than usual
• Restlessness and pacing
• A reduced appetite

It's not always necessary to see a vet if your dog has vomited once, especially if it seems fine in itself. However, the PDSA recommends monitoring it closely and calling your vet for advice if it vomits again or develops any of the following symptoms:

• Retching (trying to vomit but not bringing anything up)
• Low energy (lethargy)
• A bloated tummy
• A painful abdomen
• Vomiting for more than 24 hours
• Vomiting constantly with no breaks
• Vomiting and is very young or very old
• Vomiting and is otherwise unwell/has other illness
• Blood in their vomit
• Signs of dehydration (sticky gums or sunken eyes)
• Disorientation or collapse

If your dog is repeatedly trying to vomit but not bringing anything up (retching), you should contact your vet immediately, especially if they also have a bloated stomach. This could be a sign of a condition called twisted stomach, which can be life-threatening.

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