She would probably be eliminating more as well, but just take her to the vet
for a blood test if you are suspicious. Nothing like peace of mind. Nice to
have something to compare against for other times as well.

Karen

Gill,

Try to relax a bit - She doesn't need as much water because she's peeing a
lot less.  Sugar in urine (glycosuria) causes  diuresis, which in turn
causes polyuria (>normal urination).  Polydipisia (>normal water
consumption) in diabetic cats is a compensatory reaction to polyuria to
prevent dehydration.

If I were you, I'd take her back to the vet to check her blood and urine
glucose concentrations and hydration status.  My guess is her urine glucose
is less than before - but that does not mean her blood and urine don't have
to be continuously monitored.  Cats have a high renal threshold for glucose
so her blood glucose can be as high as 300 mg/dl before glucose shows up in
the urine.  Every cat has different renal threshold.

A simple guide (remember, this is just a guide and not the actual water
requirement) for a *normal* cat's daily water needs is about an ounce/pound
of body weight or about 60 ml/kg.  A more accurate "guestimate" of water
needs is based on the cat's daily energy requirement (DER) or about 1
ml/kcal.  IOW, a 4 kg cat with a DER of 45 kcal/kg/day or 180 kcal/day, has
a daily water requirement of about 180 ml/day or about 6 oz.

Calculating daily water needs for diabetic cats is *very* tricky (without
measurements) and is highly dependent on the degree of polyuria.

Are you feeding her canned or dry r/d?  A 5.5 oz can of r/d contains about
140 ml of water or about 4.5 oz.

Phil