I see my mom often, but I make excuses to see my mom just so I can walk her dog
Explain what you mean by making excuses to see your mom?
I really enjoy walking her dog.
It's okay to want to spend time with your mom's dog, but there is no need to make excuses. You can spend time with the dog and your mom, both of which are positive things that everyone probably enjoys.
It's pathetic, isn't it? I can't help but make excuses. I'm just so looking forward to the walks that I can't deal with any other reasons.
It is a tough habit to break, but you are acknowledging it and that is a good start.   Just tell you mom how much you enjoy walking the dog.   Make it a routine and also use it as a chance to spend time with her.