Gosta the narcoleptic cocker spaniel puppy melts hearts after falling asleep mid-play in viral TikTok videos

Gosta had barely started the journey to his new home when his owners realised something was very wrong.

The nine-week-old cocker spaniel had just been collected from his breeder when he suddenly collapsed.

Three days later, they had a diagnosis.

The tiny black-and-white puppy had narcolepsy with cataplexy — a rare neurological condition that can cause sudden sleep and a loss of muscle control.

Now 15 weeks old, Gosta has gone from frightening his owners with his sudden collapses to melting hearts around the world.

His family, who live in Sweden, have been documenting his extraordinary life on TikTok where footage of him running and playing — then suddenly keeling over — has attracted millions of views.

“Too cute!” one follower wrote.

Another simply posted a string of love-heart emojis, while others described the puppy as adorable.

But for Gosta’s owners, the videos are about more than cute puppy content.

They want people to understand what narcolepsy and cataplexy actually look like — because to an unsuspecting stranger, Gosta can appear to be in serious trouble.

He can be charging around on a walk, playing, eating or investigating something exciting before his legs suddenly give way.

Sometimes, he falls asleep. Sometimes, he remains awake but loses control of his muscles — a symptom known as cataplexy.

Then, just as suddenly, the episode passes and Gosta is back to being a puppy.

His owners say they picked him up from the breeder at nine weeks old and he began showing symptoms that very same day.

The condition can be triggered by excitement, with eating, playing and walks among the activities that can sometimes send Gosta into an unexpected nap.

But it doesn’t happen every time. And his owners are determined that his condition will not define him.

Gosta still runs through the woods, carries sticks far too big for him, plays with his brother Sam and even manages to “help” around the house.

One of his videos shows the energetic puppy charging along before suddenly stopping and lying down.

It had attracted about 1.6 million views within days.

His TikTok account has since become a global curiosity, with thousands of people following his daily adventures and leaving messages of support.

Some viewers have admitted they initially thought something terrible had happened when they saw him collapse. Others have simply fallen in love.

But Gosta’s family want the focus to remain on the life he is living between the naps.

They have explained that the dramatic collapses are only a small part of his existence — and that he is still a happy, playful puppy.

“Sometimes eating can trigger cataplexy, sometimes it doesn’t,” they wrote.

“Sometimes play can trigger an episode, and sometimes it doesn’t.

“He doesn’t just have narcolepsy, he has a life.”

That life, judging by the reaction online, has already attracted quite an audience.

Gosta’s owners say they hope that sharing his story will help people recognise canine narcolepsy and understand that what can look terrifying is not necessarily an emergency.