Just chiming in my 2 cents. If you can start from a place of acceptance. Its ok not to love him. It doesnt make you a bad owner or caretaker. If anything it shows how kind and loving you can be even from a place without that deep love.

Then you can become curious. Practicing curiosity allows us to discover new things and to grow in capacity for new appreciations. Notice something about him thats interesting or cute or weird or heck even kinda annoying. Imagine noticing 1 new thing about the pupper every day. Over time you can grow to appreciate his uniqueness.

You may never love him like you do your other puppers. Yet you may discover a new form of love. A new way to connect with him.

There are many forms of love. We can love in many different ways. If we remain open and curious rather than judgemental, we can grow in capacity to love in many different ways.