Leave it to Pixar to make us cry. After all, they just took home the Oscar for Best Animated Short Film with Bao, and the animation film studio has been tugging on our heartstrings for decades, with heart-warming films such as Toy Story, Up, and Inside Out – to name a few.

So it's no surprise that their newest short film, Kitbull, produced under its SparkShorts programme, has just gone viral. It's had 13 million views since its release a week ago.

The nine-minute short tells of the unlikely friendship developed between an abused pitbull and a stray kitten. Fair warning, though: when you watch it, you may just find yourself shedding a tear or two (especially if you're an animal-lover).

The film was directed by Rosana Sullivan, who has worked as a storyboard artist with Pixar Animation Studios. Kitbull is a bit different from other Pixar shorts as its created in 2D from hand-drawn animation.

Sullivan explains the inspiration behind the short: “To be honest, it started from a cat video. I loved watching cat videos in times of stress,” she says in another video Pixar posted. “At first, I just wanted to draw something that made me feel good and was fun, but it evolved into something more personal to me eventually.

“Growing up, I was always very sensitive and very shy, and had actually a lot of trouble making connections, making friendships. So I related to this kitten because it never really stepped outside of its comfort zone to be vulnerable and make a connection.”