Red Kongs are recommended for dogs with an average chewing temperament. Medium Kong - Cocker Spaniel, Beagle, Sheltie, Lhasa Apso, Standard Schnauzer, etc. Large Kong - Lab, Golden Retriever, Dalmatian, Collie, Chow, Boxer, etc. King Kong - Rottweiler, Mastiff, Bull Terrier, St. Bernard, etc.
Proper sizing is more dependent on chewing temperament than on breed.
When in doubt choose a larger size. These are FREE and available at your local retail pet store. The last one-third can be filled with canned food or food roll mixed with more nuggets or biscuits. Birds love the challenge of unstuffing their Kong. Begin with a mixture of nuts, fruit and manufactured bird treats and fill the cavity.