Oh, and forget to mention the "scruff of the neck" test. If you pull the scruff of his neck, it should snap back pretty easily if he is fully hydrated. Dehydrated kitties skin has no elasticity and it sort of slowly retracts afterward. The vets often do this test on them without us noticing. It is an easy indicator of hydration inbetween bloodworks. Try practicing on healthy kitties (if you have another) or on him in a rehydrated state to see what it should do. It is a useful test for seeing if he needs more fluids.
Some of this may be in advance of where you are at the moment but it is good to know later if you get to the point of giving Ringer's drips at home.
Some of this may be in advance of where you are at the moment but it is good to know later if you get to the point of giving Ringer's drips at home.