Table of Contents

Hamster Pellets and Lab Blocks

What is a pelleted diet?

A pelleted diet is the most common form of feed used in laboratory animals. It is easy to store and handle, is considered less wasteful, and prevents hamsters from selecting their favorite ingredients. They are convenient and require little to no preparation.

Pelleted diets are also considered to be “nutritionally complete and well-balanced”, which assures people that their hamster will at least be consuming a combination of fats, proteins, fiber, carbs, vitamins, and minerals that meet their nutritional needs. Hamsters can be raised and maintained successfully on a pelleted diet.

The main problem with a diet that is mainly pellets is the fact that there is no variety. Pelleted diets that are used in labs tend to be very high quality due to the fact that they need to ensure that there are no variables in terms of nutrition. Purified and chemically defined diets are very expensive to produce because of the quality of ingredients used.

However, not all pellets are created equally. According to Dr. Patrick Mahaney, a holistic veterinarian, feed-grade ingredients have a higher allowance for toxins (such as mold-produced mycotoxins) than human-grade food. Some of the ingredients used in lower-quality pellets may also be questionable or dangerous to your hamster. Some of these ingredients are food dyes, BHA, BHT, Propylene Glycol, and Ethoxyquin.

Pelleted food that has corn gluten, wheat gluten, and meal by-products may be indicators of a lower-quality food. If a pellet is not durable, it could also be a sign that it’s low quality.

There are different kinds of pelleted diets, we name and describe them below.

Natural Ingredient Diet

A natural diet is any pellet that is formulated using agricultural products using ingredients such as whole grains (like ground corn and ground wheat), mill by-products (wheat bran, corn gluten meal), high protein meals (soybean, fishmeal), and other livestock feed ingredients (dried molasses, alfalfa meal). Most diets that are commercially sold are natural ingredient diets and these are usually inexpensive to manufacture.

However, with natural ingredient diets, no two batches are identical as soil and weather conditions, fertilizers, harvesting and storage procedures, and other factors can influence the composition of the pellet. Because of this, the nutritional factors that are listed are typically their minimum value.

Purified Diet

These diets are typically formulated with a more refined set of ingredients and only relatively pure and invariant ingredients are used in these formulations (such as casein, sugar and starch, vegetable oil, and lard). The nutrient concentrations in these diets are usually less varied and are more easily controlled. They also tend to be more expensive to manufacture.

Chemically Defined Diet

These diets are made with the most elemental ingredients available such as specific sugars and vitamins. They tend to be used in studies with strict control over nutrient concentration and thus are typically more expensive to manufacture.

What is a lab block?

A lab block, also known as rodent chow, is the food specifically formulated for rodents kept in a laboratory. These blocks were formulated in order to provide the essential nutrients needed for the lab animals and sustain their health during research. Some of the higher-quality lab blocks have also been found to sustain rodents for long-term research.

According to Purina, rodent laboratory chow has been the standard of bio-medical research for about 5 decades. Many lab blocks such as Envigo-Harlan Teklad, Mazuri Rat and Mouse, and Rodent Laboratory Chow are designed to accommodate various species of rodents.

According to, a resource for wildlife rehabilitation, lab blocks also have three respective categories:

  1. High-Performance Breeding And Reproduction - Contain relatively higher percentages of fat and are higher in energy content.
  2. Growth or Full Cycle Diets - Have a more balanced protein-to-fat ratio and are intended for normal growth rates.
  3. Maintenance - Have a higher protein-to-fat ratio and are designed for longer-term captive environments.

Benefits of a Pelleted Diet for hamsters

Pellets provide reliable and consistent nutrition
Scientists, wildlife rehabilitators, shelter owners, and rodent keepers gravitate towards pellets and lab blocks because they want food to be reliable and consistent while still giving the animals the nutrition they need to survive.

Pellets can Prevent Obesity and Limit Gastrointestinal Issues In Hamsters
In 2021, Baldrey stated that a complete pelleted diet should be the predominant foods for hamsters. The reason for this is that hamsters may become selective when given muesli mixes, which can lead to dietary imbalances and obesity.

Pellets are cost-effective and widely available
Pellets, especially when purchased in bulk, are relatively cheap when compared to other commercial options available. For people who care for many hamsters, such as shelter owners, pelleted food gives their hamsters the nutrition they need to survive at a low cost. Pellets and blocks are also widely available and can be purchased online, at pet stores, or directly from the manufacturers in bulk.

Pellets are convenient
Because they are a block food, they require little to no preparation. You simply scoop it up, distribute it, and wait for your hamster to consume it.

Pellets are easy to store and transport and have a long lifespan
Since pellets are dry, they are easy to store and transport. As long as the container is kept clean and dry, pellets can also last a long time.

Pellets can be used as emergency or hospital food
When your hamster is sick and diet is the one thing you want to rule out, providing a hamster with a high-quality block diet can sustain them while giving them consistent non-varied food. People have also found success with turning lab blocks into mush to give to their hamsters as an emergency food mix in substitute for other emergency food like critical care. This mush can also be used for older hamsters who may have a harder time chewing

Pellets provide hamsters with gnawing enrichment
Since pellets are solid, hard, and a bit coarse, they can help wear down your hamster’s teeth and provide them with chewing enrichment.

Drawbacks of a Pelleted Diet for hamsters

There have been quality concerns with pellets
One of the concerns people have regarding pellets is the quality of ingredients put into pellets. Some of these ingredients in question are low-grade agricultural by-products, animal products, and ingredients not considered to be healthy or potentially dangerous for hamsters to consume.

Serving only pelleted food means less variety
Having only pelleted food often means depriving your hamsters of a variety of food which can be frustrating for your hamster.

Some hamsters do not like pelleted food
Many hamster keepers have reported that their hamsters have refused to eat pelleted food. Many hamsters do not like pelleted food or have been slow to accept it. Hamsters and other rodents in shelters or under rehabilitation facilities have also been found to reject pelleted food.

Pelleted food does not offer a sample of natural foods hamsters may find in the wild
Lab blocks aren’t the kinds of foods that hamsters would naturally find in the wild and do not do much to replicate their natural diets. The use of pellets and blocks doesn’t really offer your hamster even a sample of the natural foods they may be able to get in the wild.

Higher quality pelleted food may not be available in all areas
While there are many hamster pellets available, not all of them are built equally. While low-quality rodent feed may be easily accessible, this may not be enough to healthily sustain a hamster throughout their entire life.

Higher quality pelleted food can get very expensive
For those seeking specific lab blocks, or pellets with particular ingredients and formulations, it may cost much more to acquire them. In some countries, access to high-quality lab blocks is only available by importing them at a very high cost.

Are pellet-free diets dangerous for hamsters?

Pellet-free diets are not dangerous in the same way that pellet-exclusive diets are also not dangerous. Hamsters could be successfully sustained on both feeding approaches. What matters is that your hamster meets their daily nutritional requirements.

Diet-related deaths and illnesses are often caused by feeding unbalanced diets or food with questionable, inappropriate, or dangerous ingredients.

Why do we only recommend feeding hamsters pellets specifically designed for hamsters?

Hamsters are not dogs, chickens, rabbits, etc!

Dog kibble and chicken pellets are the most commonly used block-food supplements given to hamsters that aren’t hamster or rodent pellets. These are normally used because of their accessibility—dog kibble and chicken feed are both cheap on the market and can be bought at most major grocery stores or feed shops.

What if the ingredients all look like they’re safe for hamsters to consume?

While hamster pellets and chicken pellets/ dog kibble/ rabbit pellets, etc. may share similarities, it’s really important to understand that these animals have significantly different dietary requirements.

Hamsters are omnivorous rodents that primarily eat a diet consisting of grains, seeds, and insects. Dogs are opportunistic carnivores with a different set of dietary requirements such as a significantly higher protein intake. Rabbits are herbivores and their pellets are richer in fiber and are usually made of hay. Chicken pellets are specifically formulated to meet the needs of chickens which includes high protein contents and specific vitamins and minerals.

Feeding hamsters these inappropriate pellets could lead to imbalances in their diet, potentially causing nutritional deficiencies and long-term health issues.

Dangers of Inadequate Nutrition from Inappropriate Pellets for Hamsters

Perhaps the most important case is that pellets for other animals, such as dogs or chickens, were specifically formulated to meet the needs of those particular animals which have different nutritional needs than those of a hamster.

We reached out to Dr. Leo Almelor RN DVM, an exotic vet based in the Philippines (where it is common for people to feed their hamsters species-inappropriate pellets). He stated that there are dangers to feeding hamsters low-quality and species-inappropriate food. He says chicken pellets (notably the cockfighting pellets) often contain high fat and high protein that can lead to kidney and liver problems in hamsters. He also notes that there are very limited medicines for vets in the Philippines to use when treating hamsters with these problems.

According to the Ontario Hamster Club, many Syrian hamsters experience kidney failure towards the end of their lives. Feeding your hamster pellets with excessive sugars and high protein can place more stress on the kidneys and exacerbate any existing kidney issues. It’s absolutely vital that we feed them the appropriate food throughout their lives to reduce any suffering and prevent diseases.

Pellets formulated for other animals also have varying vitamin requirements that may not be suitable for your hamster. If your hamster has excess vitamins or is deficient in certain vitamins, it can be dangerous for their health. For example, having too much Vitamin A can cause serious liver problems in your hamster and they can even die from it. If they were deficient in vitamin A, they could develop painful stomach ulcers that could be fatal.

An improper diet can also lead to fluctuations in blood sugar levels causing hamsters with diabetes to struggle to maintain stable glucose levels. Many hamster keepers are already concerned with their dwarf hamsters getting diabetes.

In an interview with The Hamingway, Dr. Almelor emphasized, “We should avoid low-quality diets and focus more on healthy and balanced diet for hamsters. Recently we have emerging diseases with diabetes in hamsters also. So it’s really important to provide the best diet for them to prevent these diseases.”

But wouldn’t it be okay if it’s only part of the mix and we aren’t exclusively feeding them that?

We strongly advise against including these species-inappropriate pellets (aka dog kibble / chicken / rabbit / etc pellets) as part of their mix. In theory, while one pellet or bad ingredient may not lead to any long-term consequences, continuing to feed your hamster these pellets as part of their long-term diet may have ill effects in the future.

One of the given “advice” I hear with these pellets is that if hamsters are not eating them, you should deprive them of their seed mix to force hamsters to consume their pellets. Hamsters being left to exclusively feed on food that is not designed for them may have negative consequences for their health.

There are other appropriate and hamster-designed and tested foods on the market. Please do not use food formulated for other creatures just because it’s cheap!

Not all pellets made for other rodents are safe for hamsters!

Labs have reported feeding hamsters (specifically Syrian hamsters) pelleted diets intended for mice and rats, and they have shown normal growth and reproduction. However, it has also been reported that hamsters grew very poorly and failed to survive on diets that were good for rats. It is important to note that because of their biology, they have different requirements from other rodents.

When adding a pellet to your diet, we recommend using pellets that are formulated specifically for hamsters. Pellets created for rodents that also fulfill a hamster's nutritional needs are also appropriate. You can see the pellets we highly recommend in our database, but some examples of these are the Envigo Harlan Teklad pellets, and the Mazuri Rat and Mouse blocks.

Stay away from hay-based pellets!

Some pellets, such as the Oxbow pellets, are made primarily of hay. While hay does provide hamsters with some fiber, it doesn’t give hamsters the nutrition they need. Hay based pellets are usually very high in fiber and not much else.

Why we don’t recommend only feeding your hamsters pellets

While hamsters can be successfully maintained on a diet comprised of only hamster pellets, we do not recommend doing this. We believe that variety is important for your hamsters, and with their already short lifespans, we believe that it is important that they get to experience diverse textures, flavors, and other nutrients your hamster can get from a food mix with lots of variety.

If you choose to add a pellet to your food mix, we advise choosing a high-quality pellet.


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