Much as I'd enjoy blaming Linda's dirt-loving habits on Bernie bin Laden, unfortunately I can't. She's been like this as long as we've had her. As soon as she gets wet, Linda finds the nearest patch of dirt or sand and flops around in it, wallowing and snorting like a pig until she's thoroughly coated from head to toe, which also works it as deep into her fur as possible so we can enjoy it around the house later after she dries off. Then she prances around and looks for someone to jump on so they can get as gloriously grubby as she is.

Max used to look at her with a puzzled expression, trying to figure out why she was doing something that dopey. Then, since he was Max and never worried too much about things he didn't understand, he'd deal with it by biting her in the ass until she got mad enough to stop wallowing and chase him around instead (in addition to being a grimy pig, Linda is easily manipulated).

As many faults as Bernie has, he's a lot cleaner than she is. Achieving Linda's level of sheer filth takes more time than he's willing to invest, since there are so many other things that require his personal destructive attention. I'd like to think that Abby would have had more sense than both of them if they'd ever met.