A video showing a dog growing from a puppy to full-grown in 40 seconds has clocked up more than a million views on Youtube.

The aah-factor video, starring Dunder the German Shepherd was filmed over ten months as the dog grew up.

Dunder the puppy: Youtube

Dunder is filmed in the same shot for each shot, and as he gets older is sometimes accessorised with sunglasses or a headband.

On Dunder’s birthday he wears a hat and his owner hold up a number one.

Youtube: Puppy to adult video

Youtube viewers have left gushing comments about the dog.

“What a beautiful dog! We watched this a few times, it is so very cute. Thank you!” said catherinealdersey.

German Shepherd Dunder

But amusingly, the ever-dirtier floor has attracted almost as much attention.

“Haha the floor got dirty too! love this video! Dunder is so cute :D” said 29nancie.

While Cyzos1 wrote: “anyone else notice the concrete underneath him slowly got grubbier too?”

Watch Time Lapse: Puppy to adult in 40 seconds