We really try not to.. We bought some of the Jennie O and it tasted so good we ended up eating too much.
We try to just stick to the occassional serving of turkey bacon, and no more than a couple slices at a time.. It's not on plan, but it's lower in fat and much lower in sodium than the sausages.
And again, it's an occassional treat.. Maybe once every couple of weeks...
I haven't done this myself, but I would google "low sodium turkey sausage" and see what you find..
You can also make your own, using super lean ground turkey, lite salt or "NoSalt" alternative, as well as lots of other spices.. I've done this in the past to make my own patties... Not quite the same, but much better for you!