Cats may not be technically insane but they will start acting funny on occasions. Being a Tim cat (my term for a neutered tom), there could be another cat nearby that has stirred up territorial instincts in him, which can lead to the window screen being slashed, sudden attention on humans, and vocalizations. Could also be his way of saying that he wants a different type of catfood.
My Nipper (female spayed dog) is the same way with me as you state your dog is with your mother. I go to the bathroom, she follows me in there more times than not. I go to bed, she jumps right in, I head out to feed the chickens, she leads the way to the run. I leave on a three day vacation, she sits out there where I park my truck and only comes in at night to get up on my bed, snuggle down on my pillow, and growls at anyone who bothers her. She doesn't mope quite as much if my hubby stays home as she does when we both leave, but she does express her sadness I left without her. It can be pouring down rain and sleet but if I head out the door Nipper, who cuddles under a blanket when it drops to 72 degrees, will head out there with me and give me big sad eyes for not being smart enough to stay in the house. She has a bond and I am her charge to be protected. If your mom is the one that stays home the most, is the one who dispenses the food and water the most, and happens to be the one that did most of the housebreaking, your dog has probably latched hold of her as the one to be protected and the alpha of the pack. Not OCD but plain ol' doggy sense.
