Islam considers certain animals impure, notably dogs and pigs. This is not a “cultural” thing, it’s a “religious” thing: the Koran says this explicitly and repeatedly.
There have already been many cases of Muslim taxi and bus drivers who have refused to accept even blind passengers with guide dogs, because they consider the animals impure. This makes you wonder: what future will dogs have in a Muslim-majority UK, or Holland, or Germany, or Italy and so on?
Generally speaking, what will be the future of all animals, not just dogs, in a Muslim-majority Europe? Will the conquests (albeit small but still conquests) already made for the animals continue, will they be maintained or will they be eroded?
I very much doubt that we can be optimistic, if we look at how animals are treated in the rest of the world.