with humans, this can be a sign of diabetes. Often this starts with low blood sugar attacks before the higher blood sugars start.
Humans can also have nightmares at night when the blood sugar falls. Normally the liver detects this and starts converting amino acids to glucose (gluconeogenesis), but then the pancreas over-reacts and makes too much insulin and the net result is LOW blood sugar. The shiverings echo the shaking humans get.
Try giving her some food before bedtime. See what happens then. It may not show up clearly in blood work... as it often does not in humans either!
It is just a thought.
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All truths are easy to understand once they are discovered; the point is to discover them.-- Galileo Galilei
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Weezie looking at petunias 8.25.2017
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