Raw, frozen beef heart chunks. 1kg and 2kg (approx).
Heart is rich in iron and zinc and is a great source of thiamine, vitamin B6 and B12, phosphorus, copper and selenium. However it is high in cholesterol, so don't feed it too often. Organ meat should make up 10% of your dogs diet.
Feed as part of a nutritionally balance diet for working dogs.
Disclaimer: Dogs should be supervised at all times whilst feeding and always provide plenty of fresh water for your dog.