I'm sorry... But there are people here who are saying "Aww! Poor wolf!" Two things... 1 I highly doubt these wolves would let the average citizen, or anyone really, close enough to spray paint them. That brings me to two... As before this is probably to mark them for something. Probably by the zookeepers. It's also more than likely non toxic such as food coloring. So relax. And if it is graffiti... the zoo will find who ever did it, and take care of them, and shave the fur off so that the paint does not harm the animal.
I think this time they used the colour to mark the wolves who were supposed to stay in the ZOO and divide them from those who were supposed to travel to other ZOO but yes, they also use the spray to recognized already vaccinated pups from those who have not gotten their shot yet!
May I use this for an anatomy tutorial? I will be using other references too, and this picture will never be directly used. Only mentioned. A small sketch made by me for reference within the Tutorial may be uploaded, but not for money or points. Just covering my bases and making sure you ok with it before I start.