I've seen some in real as well while driving through an industrial area. I believe it's the effect of chemical hue and temporary. It's not serious for dogs. Also it's not from inside but because dogs go and sit ihe water that's flowing out of copper factories. Not dangerous for animals.

No! This is more interesting. 
Edit: Oh, it's also as a result of chemical pollution? 

siggy47

Have you not listened that Blue Dogs are not very rare in India.

https://youtu.be/Y69ri7_TiZQ?si=66SHTle_yRqQ_5zQ

Animal_World

Experts Baffled By Blue Dogs

Thanks for sharing. 
Have you not listened that Blue Dogs are not very rare in India.
https://youtu.be/Y69ri7_TiZQ?si=66SHTle_yRqQ_5zQ