I am living in an apartment and my neighbor and I share the same washing machine and dyer. They were keeping their friend’s dog for a few days in their house. Today after taking my clothes out of the dryer, I found a few of the dog’s hairs on my clothes and I am certain they belong to the dog (the hairs are thick and same color as the dog). It is obvious that my neighbor had washed their clothes with dog hairs on them therefore making my washing machine and dryer najis. I could say perhaps these hairs were stuck to their clothes they were wearing and fell off and ended up in the dryer when they were taking their clothes out although this is not very likely. I will not be comfortable even saying there is doubt in this case because it is obvious an extremely high probability of najasa and it will affect the purity of all of my clothes from now on when I wash them in the washing machine.