Personally, I don't use Nurti-Cal at all. I use light karo syrup. I wouldn't recommend against the Nutri-Cal but I have gotten away from it. My vet has told me that karo gets into their system faster (5 minutes vs 20 minutes for Nutri-Cal). Since my primary concern is getting something into their system fast, I opt for the karo.
I already stated I don't think a healthy pup that is eating well needs added sugar. Giving too much added glucose can interfere with the body's ability to produce its own. Glucose supplements can be a life saver but are no substitute for a dog eating well.
Here's a link to an article that explains some of the processes....
Metabolic Functions of the Liver