When I first got my ferrets, I wondered what food would be best to feed them. The breeder I got my first ferrets from recommended a good quality cat food with high protein or 8 and 1 Ferret Food. 10 years ago, there were not as many types of ferret foods available as today. If you do not have a good variety of ferret food at your local pet store, you can feed ferrets cat food instead.
When analyzing processed dry cat foods unfortunately, the nutritional analysis doesn’t tell the whole story. You must also analyze the ingredient list as the quality and availability of the proteins and fats can vary widely. However, even ingredient lists can be misleading. The foods listed first are the highest proportion of the diet, but you have no idea exactly what proportion. Be aware of ingredient splitting, which can push similar but less desirable items down the list, but if added together might make up a high proportion of the diet (e.g. soy flour and soy meal). A good rule of thumb for protein content is between 60-80%.
Protein Sources: Look for meat and meat meals as opposed to “by-products.” Meat and poultry by-products are the bits that don’t make it into human foods, and may be low in digestibility and therefore not really a useful protein source. Eggs are also a high-quality protein source. Look for meat or meat meals or eggs to make up the first three ingredients (you’ll find very few foods that make this requirement – but definitely avoid any that do not have high-quality proteins or fats as at least most of the first 6 ingredients). Beware the use of corn gluten, soy meal, rice gluten and other vegetable or grain-based proteins that may boost the protein content, but are not useful to ferrets. Also watch for added sugars (sucrose, fructose, corn syrup, etc). Just a note: ferrets may not like the taste of foods high in fish (and they may make the litter box pretty smelly too), though some cold water fish such as salmon is an excellent source of fat.
For many years, the common recommendation was to feed the premium dry cat or kitten food, but that recommendation is now considered out-of-date. As the science of ferret nutrition improves, there is little doubt that premium ferret diets are now the best to feed ferrets. Still, if you are unable to find a good quality ferret food (consider ordering online if nothing else) you may have to settle for cat food. If so, make sure it is a premium diet (e.g. Use a kitten food, high in protein (60-80%), but as your ferret gets a bit older (4 years or so), switch to adult food. Again, you must check labels, and pick foods with only high-quality animal proteins at the top of the ingredient list, and make sure they are high in fat and very low in grains, sugar, and fiber. Avoid generic or “grocery store” brands at all costs, as these are typically very poor choices for ferrets.