Husband suddenly abusive towards dog

Six years ago my husband and I adopted a puppy from the shelter, she was from a puppy mill and had scarring from neglect at only 6 weeks old. She was our baby. She has never been an easy dog but my husband has always been her “person”. She loves him most. The past six months or so my husband has been really aggravated and and mean to her. Our kids love her and give her hugs and for some reason this bothers him because he says she’s “dirty”. But he has completely stopped bathing her. She is a really big strong dog and I have difficulties bathing her but I do so anyway. I misplaced her flea and tick meds and I was like “can you help me find them? She’s due.” And he was like “I don’t care, she’s a dog. That medicine is expensive.” Lately he’s also been smacking her on her rear end if she goes in the kitchen. And yesterday he was trying to mow the grass and got pissed off there was poop everywhere and was complaining that she doesn’t poop in just one spot but goes all over the yard. I’m thinking to myself, well then do a better job at picking up the poop! When she comes over to greet him he always tells her to get and leave him alone. It’s like he randomly hates her and he never acted like this before. Idk what to do.