I'm a dog. (Ok, no smart-mouth comments.

)
My owner picks me up and puts me in this very confined space. I feel something under my feet I've never felt before. I take a step to test the surface and my owner corrects me and tells me to stand still. I try again because I've never felt this type of flooring before and I want to understand it. My owner is getting upset because I won't stand still. Suddenly this thing starts spraying water.
Ok ... stress, anyone??
Mauser LOVES water. We have a plastic kiddie pools he lives in during the hots months and when we go to the lake it's hard to keep him out of the water.
He LOATHES the bathtub - because I never bothered to teach him it could be a fun place.
Luckily we have a walk-in shower in our first floor bathroom that he's not as afraid of so we use that for the most part. But one of these days I have to
TEACH him that the bathtub can be a fun place.
Mauser loves tennis balls so here's my plan. The bathtub is in the 2nd floor bathroom so I'll grab the ball, tease him with it and get him to chase me up the stairs and to the bathroom door. Then I'll toss him the ball and chase him back down the stairs (he likes being chased).
Repeat, repeat, repeat. After a few of these I'll toss the ball into the bathROOM, wait for him to go get it and then chase him downstairs.
Repeat, repeat, repeat.
Then, while we've got this momentum going I'll run into the bathroom and toss the ball NEXT TO the tub.
Repeat, repeat, repeat.
Then the ball gets tossed into the tub. If he won't willingly jump in and get it I'll reach in, take it and hold it right over the edge of the tub for him to grab.
Repeat, repeat, repeat.
Baby steps!! Getting him more and more comfortable with being in the bathroom, then near the tub, then IN the tub.
Never force the issue or you set yourself back to the beginning.