"Gluten Free" sausages are made for people with Celiac Sprue, also known as Celiac disease. This is a genetic disease which interferes with the digestion process. When a celiac person eats foods that contain gluten, the immune system responds by damaging the villi in the small intestine. Gluten can be found in wheat, rye, barley, and possibly oats.

These sausages are often made with rice flour. I am under the impression that rice flour is high in carbohydrates.

Here in Melbourne, the Victoria market is far cheaper than the supermarkets but you are taking your chances with foods because nothing is labelled at the butchers. All they will tell you is that the sausages are gluten free and made with rice flour.

If you want low carb sausages then the Polish or Kransky style at the supermarket is an easy choice. However, these generally come smoked (Red in colour) and have a different taste to the traditional pork sausage. The upside of the supermarket is that many of the sausages have nutritional labels, so you may still be able to find a relatively low carb regular sausage.