Introduction

A critical choice and challenge facing wildlife rehabilitators of small rodents (e.g., tree, ground and flying squirrels, chipmunks, rats and mice) is the selection of a suitable diet for weaning and post-weaned animals prior to release. Many rehabilitators have turned to one or more of the commercially available rodent chow products to meet this need. Other rehabilitators have chosen not to use these products.

This paper discusses some of the reasons that rehabilitators indicate they are attracted to use these products, and why some have avoided them. This paper gives an overview of 39 different rodent chow products available from several different manufacturers, including their recommended uses and applications, and product composition and ingredients for those considering rodent chows. Additionally, it discusses certain criteria that can be helpful in selecting which product or products to use in certain situations.

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The first decision facing a wildlife rehabilitator that rehabilitates the small rodent species groups listed above is whether to use rodent chow, or some other weaning and post-weaned diet, or some combination of both. The following presents some of the most commonly cited reasons that rehabilitators use rodent chow or why they do not.

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Reasons Why Rehabilitators Use Rodent Chow Products

Many rehabilitators want a reliable and consistent product that provides the proper nutrition to the animal. Some of the higher quality commercially available rodent chow products have been specifically formulated and manufactured for long-term research applications where a complete and balanced nutrition regime must be maintained under very stringent and controlled conditions.

Using a purchased product precludes the challenges and uncertainties of trying to create a fully balanced and nutritious diet from other food sources. It also results in much less time and effort (and cost!) in attempting to acquire and prepare a fully “natural” or “wild” diet. While rehabilitators certainly place fresh branches, buds and other natural vegetation in the cages, the use of a high quality rodent chow that the wild rodents willingly eat reduces concern that the animals are getting enough, appropriate and balanced nutrition.

Being a dry product, rodent chows are easily transported and stored. They arrive ready to feed, so no daily preparation is required. They are relatively easy to administer and provide to animals in a controlled manner, monitoring how much food is provided and consumed in a given time interval. It is also easy to grind the rodent chow and then moisten and soften with an appropriate formula or water for use with older rodents with mouth or teeth injuries.

Being a relatively hard and solid product, it provides a gnawing source for a rodent’s continuously growing incisors.

The more commonly used rodent chows manufactured by the larger companies are generally readily and rapidly available by ordering online or mail. Some may be available from local feed stores, though the higher quality rodent chows often require special orders and may take longer to arrive. 

The standard products are usually priced in the $.50-$1.75 per pound range when purchased already packaged in quantities of 20-50 pounds, making them a highly cost-effective source of food. Many rehabilitators report that purchasing a high quality rodent chow that the animals eat has reduced the cost of rodent food.

In addition to direct cost reduction for many, using a quality rodent chow has reduced time trying to achieve and shop for a properly balanced and nutritious diet. Rehabilitators also report that there is far less food waste when using a quality rodent chow, thus improving cost effectiveness. Some rehabilitators have mentioned that the rodents eat the rodent chow more completely, and it does not readily spoil like fresh vegetables and fruits they previously fed, resulting in far less time spent cleaning up spoiled and unconsumed food (and the insects attracted to decaying produce) -  thus an indirect time and cost savings. 

Some rehabilitators use a rodent chow product simply because they were told or instructed to use it by the individual who helped train them to become a rehabilitator, offered by a rehabilitation center that provides supplies or was easily available from a particular distributor. As such, a rehabilitator may have given much thought about why they use it or why they feed a particular product over another. Or what the other choices might be.

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Reasons Rodent Chows Are Avoided

Some rehabilitators have expressed concerns about the quality of some of the ingredients used in the manufacture of certain rodent chow products (e.g., low-grade agricultural by-products, animal products, and certain ingredients not generally considered to be healthy for rodent consumption). While certainly possible, some manufacturers are working to address this concern and explain specifics to customers.

Some report that rodents in rehabilitation have refused or been very slow to accept rodent chow. As mentioned earlier, identifying the reasons for reluctance may resolve this - if the rehabilitator wants to consider using it.

Some rehabilitators have expressed concern that a commercially prepared product designed for captive animals (i.e., laboratory or domestic) may not be appropriate for a wild animal. Additionally, being a commercial product, rodent chow is not a food the animal will encounter upon release to the wild. The use of rodent chow as a primary diet does not preclude offering a sample of natural foods from the wild.

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Certain specific rodent chow products may not be readily available in all areas. Absolutely true, though ordering online and having products shipped has improved availability. It does, however, require planning to ensure the product is available when needed.

Rodent chows are too expensive. While some have mentioned this, a closer look shows that rodent chows are highly costs effective when compared to other foods used to feed wildlife, as mentioned above. For those seeking very specific ingredients or formulations, some boutique rodent chows are priced in the $25-30 per pound range - and definitely consider expensive.

While there are probably other factors that may impact a decision, these reasons tend to be more commonly mentioned by rehabilitators discussing weaning and post-weaned diets.

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Types of Rodent Chow Products

Once the decision has been made to use a rodent chow product, it is helpful to understand the different types of products that are available and their intended uses. Many of the larger product lines (e.g., Teklad, LabDiet, Mazuri) are formulated for and targeted for two primary purposes:

Laboratory animals. These are typically sold to breeders of rodents for a variety of purposes and research institutions conducting studies involving laboratory rodents. Accordingly, their products generally fall into one of the following three categories:

- High performance breeding and reproduction – these products tend to be higher in energy content, containing relatively higher percentages of fat.

- Growth or full cycle diets – these products are generally more balanced (protein to fat), intended for normal growth rates and the ability to use the rodent chow in a wider range of applications.

- Maintenance – these products tend to be much leaner with a higher ratio of protein to fat, designed for longer-term captive environments, such as laboratory applications.

Many of these products are also available in an autoclavable formulation if microorganism content is an issue (i.e., some are irradiated, available in a vacuum sealed package). Some products are certified as to not exceeding specified levels of microorganisms and other contaminants (heavy metals, pesticides).

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Domestic animals. Some of the smaller manufacturers (e.g., Oxbow, Kaytee) target their rodent chow products more for domestic rodents (hamsters, mice, and rats). [Although not a rodent chow nor a product designed or formulated to provide a balanced nutritional diet for rodents, the Primate Diet from Zupreem is included in this article as it is used by some rehabilitators (though the manufacturer cautions that this product is not designed for use with rodent species).]

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Table A below presents the primary ingredients (e.g., corn, wheat, soybean, etc.) in each of the 39 rodent chow products studied as indicated in the package labeling. The table does not itemize the many other supplemental vitamins or other trace nutrients that are included in each product.

Table B below presents a comparison of the 39 rodent chow products studied, with the data presented drawn from the guaranteed analysis and typical nutritional analysis for each respective product. The table also indicates the intended use of the product as suggested by the manufacturer.