Yes dogs can eat pineapple but just don't give the dog too much pineapple at one time because it might give the dog diarrhea or an upset stomach.
But feeding the dog a cup of pineapple per day is okay and the pineapple is healthy for the dog just like the pineapple is healthy for us humans.
My dog likes pineapple and whenever I eat pineapple he has to eat some pineapple along with me.
The pineapple is a great treat for dogs and even cats.
My cat loves to eat some pineapple as well and the cat also likes to eat cantaloupe too.
Dogs and cats can eat several of the fruits that we humans eat and it's much healthier for the dog and cat than dog and cat food is.