Prepared Tortoise Diets- yes or no?

Not open for further replies.


Well-Known Member
10 Year Member!
Feb 15, 2008
Location (City and/or State)
There is an ongoing debate about the benefits or problems of using a prepared tortoise diet- should you use it, and if so, how?

We need to recognize from the beginning that there are a lot of types of prepared diets- freeze-dried, canned, and so forth. Most of the debate, however, centers around the chows, pellets or kibble types since the other forms are expensive enough that they are usually used as treats. Even within the chows, however, there are a lot of offerings and not all are considered equally useful. The three most commonly recommended chows are:

- Mazuri Tortoise Diet
Comes in 1lb or 25lb bags and costs about $1-2/lb in the larger bag, which is often available at a local feed and grain store. It is a largish pellet made up from a variety of grains and supplements. It is slightly oily and contains vitamins that deteriorate over time, so it should be used before the oils go rancid. It can be frozen for a longer life. It was originally formulated for giant tortoises in zoos. The maker states that it is a complete diet but can be supplemented with fresh food for enrichment and variety.

Availability: The larger bags can generally be bought or ordered from a feed and grain store that carries Purina products. The 1lb bag is often available, sometimes by special order, from pet stores or can be purchased on-line. Some of our members offer convenient sized packs as well and can be found in the For Sale section.

- Zoo-Med Natural Tortoise Food
Available in several sizes from 8.5oz to 50lb. It averages $2/lb in the 50lb bag. This is a smaller pellet, similar to a rabbit chow. It also contains mostly grains but uses many plant sources for nutrients, including long stem fiber which has known benefits. It states 'No artificial preservatives, colors, or flavors' on the label. I do not know if it has an expiration date, although many vitamins do deteriorate over time regardless. Zoo Med has a good reputation for making reptile foods and supplies.

Availability: Widely available in pet stores or on-line.

- Marion Zoological Red Tortoise Sticks
Relative new-comer, it is very similar in many ways to Mazuri, except it comes in different pellet sizes and is colored red, which probably increases the tortoise's interest. Available in 1lb and 25lb bags, although not as widely available as Mazuri. Costs about $2/lb in bulk. Probably has the same shelf life as Mazuri for the same reasons. Marion Zoological has been making high quality bird feed for some time, and has applied that knowledge to a few other categories.

Availability: Coastal Silkworms seems to be the primary retailer- He is also a member and offers it in the For Sale forum.

This does not mean that other chows are bad in any way- these are just the ones most often recommended and used on this forum.

Whether you use a chow or not depends at least somewhat on your philosophy of animal diets, as well as factors like cost, convenience, etc. There are generally 5 main points of view here- and these same thoughts can apply just as well to raising rabbits, fish, birds, or cats and dogs.

People in this group are confident that the makers of the chow have created a solid, balanced, and nutritious diet for the animals, and appreciate the cost and convenience of the prepared diet. Others, however, believe that even the best scientific diets have some weaknesses, such a lacks of micro-nutrients. inadequate vitamin doses, the effects of aging on ingredients (rancid oils, deteriorating vitamins, etc.), lack of variety or enrichments, lack of 'that certain something' present in 'real food' (or the idea that real foods offer subtle, possibly unrecognized benefits not present in prepared foods), and so we have other categories...

This category feeds their animals mostly chows or kibbles, with some fresh foods on the side to add interest, variety, and to help offer micronutrients that may be missing from the chow. Many prepared food makers suggest or recommend this version to some extent.

Recommended by veterinarian Greg D. Harrison to prevent what he calls the 'Improper Diet Cascade'. The idea is that the fresh and prepared foods will balance the weaknesses in the other half. He also points out some things to consider when using prepared diets, such as storing them as to prevent rancidity. (In the interest of disclosure, this is the method I recommend.)

The idea here is that a good diet built on variety, balance, and locally available produce is the best food for most animals, but that prepared chows can offer some benefit as well, so they are used as a supplement to help ensure good nutrition, or when fresh foods are less available.

Self-explanatory. People in this category feel they can buy or grow foods that serve their animal's needs well and/or that there are problems in commercial chows. Just as there are concerns about 'all chow' diets, there are concerns that it is very difficult to correctly simulate a wild diet with locally available produce or plants. It has been suggested that without more research and preparation than most people are willing to do, that it can be very difficult to ensure that the foods offered actually meet the needs of exotic animals.

There are pros and cons with each of these opinions, and plenty of good research and practical experience for each as well. There are some who use one category for baby animals, and another for adults; and some who use one category for this sort of animal and another category for another sort of animal. Others vary according to the seasons or whether their animals are indoors or out. As you consider which category you will use with your animals, here are a few other things to consider:

- Fresh food availability. Depending on where you live, you may have more limited access to buying or growing your own fresh food. It may not grow in your area, there may be a lower demand for it locally, there may be seasonal issues, etc. The less fresh food you have available, the more you may need to at least supplement with prepared chows.

- Suitability. We cannot easily match an animal's wild diet with food we can raise or buy locally. We cannot easily ensure the right mix of calcium, iron, phosphorous, minerals, vitamins, calories, carbs, etc. We can compensate quite a bit by offering the largest variety we can, and offering smart supplements- but this does take some thought and knowledge to do well. Prepared diet supporters claim that this is perhaps more difficult than the typical person can accomplish.

- Inappropriate foods. Fresh food supporters often point at the grains and other ingredients in chows as evidence that they are unsuitable. There is a difference, however, between raw grains (which neither we nor tortoises can easily digest) and processed grains which unlock the nutrients and make them accessible. The use of sweeteners is also often questioned, but they are used to provide carbohydrates and encourage the appetite. There is evidence that tortoises may prefer to eat sweet pellets over natural foods, but withholding the pellets for a while usually seems to put things right.

OK, so what is the bottom line here? Prepared foods, natural foods, or a combination? Truthfully... as far as I can tell... the tortoises do not seem to care. Assuming a decent diet and good cares, it seems that you can safely follow any of these philosophies. The basic question seems to be 'Which one works best for you?'

(By the way- we do this for people too. If you think about pre-prepared foods as a form of 'chows for people', you can see that we generally fall in one of these categories as well as we feed ourselves and our families. Frozen dinners, jarred baby foods, packaged cereals, canned foods, cake mixes (in fact most baked goods), meal bars, and more- few are 100% natural, and most of them contain additives or ingredients that some people feel are bad for us and should be avoided, or should only be used in moderation, etc.)

This thread will be locked to discussions. Discussion is welcome at:
Not open for further replies.