Whole prey is best! Instead of measuring out organs, meat and bone, you have it all wrapped together in a nice bundle. Mother Nature loves to make it easy for us raw feeders. Waverli eats whole 3 week quail, XL mice, L-XL guinea pigs and weanling rats from Rodent Pro. They are raised in humane conditions and euthanized with CO2.
Dogs can eat whole prey too! Rabbit is an excellent meat for dogs and cats alike. Whole chickens can be bought from family farms or from people keeping laying hens that have older animals not producing well anymore. These animals are termed "culls" and you can get them for much cheaper than normal market price animals. Culls can include wether goats, lambs, ewes/rams, rabbits, boars/sows, roosters, etc. Animals that are old, not producing well or have aggressive issues are often eliminated from the breeding stock. Instead of wasting these animals, we can use them to nourish our domestic carnivores.
Small dogs 20-30 lbs or so can eat rats, chicks, quail and guinea pigs as well but for large dogs, it can get quite expensive to feed their daily amount in small critters. Adding them in for variety is nice, but not necessary.
When buying whole prey, research the source thoroughly. Afterall, you are buying these critters for the health of your dog, cat or ferret. If buying from local pet stores, make sure the animals are fed appropriately, housed adequately with proper bedding and not overcrowded. Also find out how they are euthanized. Carbon dioxide is the best method, and painless. Larger animals like rabbits and adult guinea pigs can be killed via cervical dislocation which can be humane if done correctly. Supporting a business that cares about its animals from life until death is not only ethical, it shows other businesses that this is an important point for consumers, and could cause some less than ideal policies to change in order to keep up with competition.