Please keep us posted!!!
What is very important for bathing a rabbit probably really applies to your dog. When we bathe a rabbit (only when absolutely necessary as they can be traumatized and get sick from it) it's important to go slowly and calmly, and use warm water (not scalding, check on your wrist, but make sure it's warm enough that you'd get in it)-lather and rinse. Then towel dry several times-and then wrap in a nice fluffy dry towel and keep them
warm until they are fully dry-often I've seen people's newly bathed pets (dogs, cats etc) shivering after a bath.
With a senior this is important-make sure he stays warm until he's very dry!
I'm sending some {{Healing Vibes}} for Tiger and some {{Easy Bath}} vibes for you

Keep us posted and good luck!