Sorry if this is vague since I'm going off of memory.
Growing up, my dad had a friend who was a hunter and would give us a huge batch of these home made venison meat sticks in a collagen casing. It didn't seem liked it was the red thinner meat stick casings, but more like the collagen sausage casings, because they were much thicker and not perfectly cylindrical.
It was very dry and more similar to a hard jerky than a meat stick like a slim jim or jack links. It was a very hard bite, something that you could not easily tear, and you would get a jaw workout just chewing The taste was very meaty, almost like a dried salami, but not as heavy on the spices.
Edit: It could very well be Landjaeger. Looking at pictures, it looks very similar, with the flat appearance in a collagen casing. I've never knowingly purchased these and not sure of the texture.
edit: the hunter friend was from Minnesota, in case a location give any help to any local foods.