Well, there is certainly sugar listed in the ingredient list....why not the nutrition label? Could be 2 reasons;
1- serving size
2- manufacturer error
My guess is serving size requirements. If the serving size portion of food isn't large enough to require by law the carb counting of it's individual ingredients then they can be skipped. In this case the quantity of sugar per serving size could be less than required reporting standards.
The easiest thing to do is to take a moment at the store and check the ingredient lists of what you buy. The truth is we find "favorite" products and we stick with them, it's human nature. Once you find a product you really like that's FTS friendly the work is behind you.
Fresh sausage from the butcher is always an option. Ask your meat man to grind you up some pork, beef or turkey and instruct him or her how you want it spiced and what size links you want. You'll be amazed how much better the sausage tastes when you call the ingredient shots.