Wether some one chooses to listen to people here ,or take the advise of a vet who has had at least eight years of advanced education
Then do I count? I get to have a DVM behind my name now. Though I don't do much with exotics; I'm currently dog-and-cat only, but I had a lot of equine and exotics as part of my elective education, and I hope to add those into my practice eventually.
I wouldn't use Nutrical or anything similar in a hindgut fermenter, such as a horse or a chinchilla. This is mostly because of the high fat and sugar content; the last thing a sick hindgut fermenter needs is disruption of its GI flora. I might use Nutrical as a very infrequent treat (but there are so many other better things out there - I certainly am not recommending this by any means). Is it safe? in small quantities, yeah. Is it advised? probably not.
I wouldn't use a lot of things that are labelled for dogs and cats in a chinchilla. Even if the packaging doesn't say "carnivore," it does say "dogs and cats." I might use Nutrical in a ferret; ferrets certainly love the stuff. But I wouldn't even give that much to a ferret - there's other options for supportive feeding in them, and too much'll give 'em diarrhea (they don't have the greatest digestive systems).
In this day and age, we have Critical Care, which is an excellent source of fiber, nutrients and calories for a sick chinchilla. Oxbow even makes a large animal version (though I doubt it's economical for a critter the size of a horse). For very young kits, Nutrical might be a better choice than Critical Care (if the kit hasn't developed the ability to digest fiber well yet), but even so... we have better options for them as well.
IMO, Nutrical hasn't got a place in herbivore medicine. It may have a place in carnivore medicine, but not much of one.