Fish4Dog Sea Jerky Fish Knots Low in calories and made with fish skin. Made with pressed fish skin, they are low-calorie treats with a rough texture that will not only help remove tartar from teeth, but thanks to their rich flavour, dogs will love them. Being made with oven-dried fish skin, they are low in calories and will provide additional vitamins and nutrients important for the proper development of the animal. Your dog will love this food because: Cleaning Being hard and rough they help keep teeth clean. Fish Low in calories and rich in Omega 3 acids.