If inadequate amounts of dietary carbohydrates are available, the body will synthesize glucose from glucogenic amino acids and glycerol. (merckvetmanual.com)
Cats normally use glucogenic amino acids and glycerol to synthesize glucose, which is one reason why cats are classified as true carnivores. (merckvetmanual.com)
In cats, carbohydrates apparently are not essential in the diet when ample protein and fats supply glucogenic amino acids and glycerol. (merckvetmanual.com)