Growing up my in-laws would not allow their children to have pets. They said it was because MIL was allergic. I grew up with two giant slobbering beasts. My brothers. The three of us each had a dog. We lived on a working farm and it was sort of expected of us.
I met my wife in university and the first time I met her parents she made me wash everything I was going to wear and keep it separate from my other clothes so it would not affect her mom.
Long story short. Her mom just hated animals. Not allergic at all. We have two children and unfortunately the complications from our last child means that she will literally be our last child unless we adopt.
Our baby just went into grade one and my wife works from home. She is lonely during the day and she said she wanted a dog.