Pet Rat Nutrition & Diet Guide
Welcome to our updated nutrition and diet guide for the pet rat!
Introduction to Balanced Nutrition
The first step to understanding, formulating an implementing the right diet is to understand how the rat's metabolic systems work and what the needed daily nutrient requirements are. Both wild and our domesticate pet rats are omnivores, that is they eat plant and animal matter to provide them with substance. As rat pet owners, we can provide our rats with a diet that contains both by providing a staple diet as well as fresh whole foods for added benefit and variety. When providing fresh foods, pet owners need to keep in mind that, like humans, rats will often prefer some foods over others- typically these are foods that taste better but are not necessarily nutritionally good. We will discuss providing fresh foods below.
The daily daily nutrient requirements of the rat are very similar to that of a human - with a few exceptions of rats needing 130% of calcium, 130% of manganese, 490% of vitamin K, and 290% of vitamin B12 more than we do. A listing of the estimated Nutrient Requirements for Maintenance, Growth, and Reproduction of Rats can be found HERE. Depending on the life cycle stage of a rat, they may need a different requirement, usually by adding additional nutrients and vitamins/minerals to the current standard diet and increasing/reducing percentages within the diets. These stages of "special" diets generally are for rats in the reproductive cycles (actively breeding, pregnant, nursing), in the early development cycle (about 3 weeks to 5 months) and in the later years cycle (about 1.5 years till death).
The Staple Diet
The "staple" portion of the diet should be at least 50% of the overall diet. Some sources and experts advise a 80% proportion of the diet being the staple food. Generally, the staple is a complete rat diet that is formulated by nutritionists specifically for rats, usually this is only commerical products. This is usually easily provided through a high grade lab block that is heavily-fortified and formulated for the specific, complete and balanced needs of rats in all the life cycles. Ultimately, these complete block diets meet all the nutrition requirements for a rat and can be feed as a single diet. This cannot, however, necessarily be said for homemade diets until further scientific or nutriton studies can be done for each type of homemade diet.
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Feeding your pet rat a diet that is complete, healthy and balanced plays a very large part in the overall health and life span of your rat as well as their own well-being, happiness, how they look and even can play a hand in temperament. Good nutrition starts with implementing a health, well balanced diet geared towards a rat's needs and one that meets all of the minimum daily nutrient requirements. With so many commercial and homemade diets out there, its hard to know what is best for them. This guide is aimed to help rat owners from old to new make informative decisions about what diet they implement for their rats. The information here is gathered from various information sources and from my own experience of owning rats since 1999 - please note that I am not personally a nutritionist, work within the pet food industry or a lab nor am I a vet. As science and technology become more advanced, so to does our understanding of diet and nutrition. Because of this, we will be continuously updating this portion of the Phoenix Gate Rattery site. Currently, until more information is gained in this area to be able to formulate a complete diet, we will not be covering diets that are 100% organic, though many of the fresh foods can be safely substituted for organic ones.
For the new printable version of this article, go HERE!

Related Links
Rat Diet at the AFRMA Beginners' Corner - contains the Nutrient Requirements of Rats from the National Research Council (1978)
Diet at the Rat Care Guide on The Rat Guide - a wonderful overall layman's guide to diet
Rat Health Food from the Rat Report  - The Rat Report (The Rat Fan Club) by Debbie "The Rat Lady" Ducommun, updated 1/18/08
Nutrient Requirements of Laboratory Animals, 4th Revised Ed., 1995 - Estimated Nutrient Requirements for Maintenance, Growth, and Reproduction of Rats
The "SueBee Rat Diet" - homemade diet by SueBee
Currently there are only a handful of brands on the market that are suitable. Some can be found in pet stores, some can be purchased online in bulk and some can only be purchased through designated distribution dealers. Here is a review of currently available block and pellets along with a :
Harlan Teklad - The best block currently on the market is the Harlan Teklad blocks and they can be purchased in bulk from the manufacturer at This block can be harder to get but there are now some online sites and rat organizations that sell smaller quantities that can be shipped to you. Harlan also sells their trademark formula diets under the name Native Earth commercially to the public. Harlan makes the following formulas:
  • Native Earth 18% Protein 4018 Rodent Diet - formerly Harlan (40-lb bag) - "4018 is a fixed formula diet containing 18% protein and 5% fat." Top ingredients: Ground wheat, ground corn, wheat middlings, soybean meal, corn gluten meal, soybean oil.
Mazuri - As a suitable alternative, Purina Mills produces Mazuri which can also be purchased in bulk at the Mazuri website: Mazuri tends to be more commercially available than Harlan (PetSmart now carries it) but it also contains a higher percentage of protein and fat. Purina Mills makes a couple of different lab block formulas
  • The Mazuri Rodent Pellets - has a hefty 23% protein level and a crude fat level of 6.5%. with the first 5 ingredients listed as dehulled soybean meal, ground corn, wheat middlings, ground wheat, soybean oil.
  • The Mazuri Rodent Breeder forumulas (6F, 9F) - contain Crude protein of 16.0%, Crude fat of 9.0%, Crude fiber of 6.0% with the first 5 ingredient of ground corn, dehulled soybean meal, ground oats, porcine animal fat preserved with BHA, cane molasses
LabDiet -  Available through PMI Nutrition International Certified LabDiet Dealers. This block is included as a possible alternative source but it should be noted that the main ingredient for these formulas is corn. I have included the formulas that I have personally been able to order from a distributor in the past. More information at their website
  • Laboratory Rodent Diet 5001 - Crude Protein (min.) 23.9%; Crude Fat (min.) 4.5%; Crude Fiber (max.) 7.0% and the main ingredients of ground corn, dehulled soybean meal, dried beet pulp, fish meal
  • Certified Rodent Diet 5002 - Crude Protein (min.) 20.0%; Crude Fat (min.) 4.5%; Crude Fiber (max.) 5.5% and the main ingredients of ground corn, dehulled soybean meal, dried beet pulp, fish meal
  • Rat Diet 5012 - Crude Protein (min.) 22.0%; Crude Fat (min.) 4.0%; Crude Fiber (max.) 5.0% and the main ingredients of ground corn, dehulled soybean meal, dried beet pulp, fish meal
Oxbow - Available through online pet food sellers, occasionally in pet stores. An apple flavored block designed as a low-fat, low-protein diet with no corn. Debbie "The Rat Lady" Ducommun states that the Regal Rat Oxbow rat diet is designed only for adult rats and would not give females the Oxbow diet because a diet higher in soybean meal helps to prevent mammary tumors.  And not use the Oxbow diet for males until they are at least a year old.
  • Oxbow Regal Rat Food (3-lb bag/40-lb box) - Crude Protein 14.00% (Min), Crude Fat 4.00% (Min), Crude Fiber 7.50% (Max), Calcium 1.20% (Max); Main ingredients are Whole Brown Rice, Oat Groats, Wheat Bran, Wheat, Soybean Meal, Menhaden Fish Meal, Soybean Hulls
Sun Seed - Available through online pet food sellers, occasionally in pet stores. This is marketed mostly as a high-protein or supplemental treat. The high protein percentage and corn being the main ingredient make this not a suitable block for long term complete and balanced diet.
  • Sunthing Special Critter Cubes (32 oz) - Crude Protein 22.0% min, Crude Fat 6.0% min, Crude Fiber 6.0% max, Moisture 15.0% max. Main ingredients of Ground Yellow Corn, Soybean Meal, Ground Wheat, Fish Meal, Wheat Middlings, Animal Fat Preserved with BHA

There are a handful of other blocks that are generally not suggested for rats:
  • Kaytee Rat & Mouse block - Crude Protein (min.) 21.0%; Crude Fat (min.) 4.5%; Crude Fiber (max.) 6.0% and the main ingredient of ground yellow corn.
  • Local mills often produce their own formula's of rodent chow or block. Many times, these blocks include mostly corn, very high percentages of protein and fat, can contain foreign and non-digestable ingredients and are not stored and produced in a clean, moisture free, insect free location.

Providing Fresh Foods
Along with a daily serving of a complete balanced lab block, you will want to provide additional fresh healthy foods for variety and additional nutritional benefits. This will also help owners not over feed treats and other high calorie foods when they beg- feeding too many treats and the wrong kind of treats seems to be the biggest contributor besides incorrect serving sizes that lead to overweight issues. So when you feel inclined to give them a treat, instead give them a piece of fruit or vegetable instead. In Table 1 at the bottom of the page I have outlined a daily menu of fresh fruits and vegetables to feed along with a complete quality lob block (suggest Harlan) or rat pellet food (as an alternative). This is based on what the diet plan I have in place for my rats after years of trying diets that just did not work completely and Debbie "The Rat Lady" Ducommun's homemade diet. Table 2 has a list of foods to feed in moderation and foods not to ever be fed. These fresh foods should be provided ias fresh as possible and only in washed raw or cooked in low-fat cooking options like steamed, boiled, baked, etc.
Depending on where the rat is in its lifecycle, you may want to provide a specialized diet to support their changing needs.
For Pregnant and Lactating Females - Because they are supporting additional lives, female rat moms need additional nutrients during this life cycle like extra protein and fat in the diet. It is important to provide these additional needed essentials for their well-being and the growing needs of the babies. It is amazing the difference in the overall health, size, body condition and energy levels of these rats when the right amount of need nutrients are recieved. Pregant and nursing females should be feed only a high quality block and can be supplemented with a balanced grain mix. The block should not have a protein percentage any lower than 18%. There are some breeders who support the idea of providing cat or dog food during this time for the additional needs but there are some who believe that this leads to mean and aggressive tendencies as well. Ultimately, there are plenty of other options to provide this additional requirement she needs. Additional protein can be provided by giving soy milk, cooked tofu, cooked meats like chicken, beef and fish, eggs (can be cooked with butter to add fat). Oatmeal mixed with whole milk, goat's milk or soy milk is good for her as well. She should have plenty of clean water available to her at all times.
Older Rats - As a rat ages, his metablisms slows and they will eat less and less. Becuase of this, its important that the food they do eat is highly nutritious and geared towards their activity level, health level and overall body condition. Extra calories as well as a vitamin and mineral supplement will help ensure muscle condition and they are getting all of their nutrional requirements. You may want to provide pureed or soft foods that don't require being held to eat or sitting up if your rat has hind end paraylsis. This can be baby food, pureed fruits and veggies, the lab blocks that are soaked in soy or water, fresh foods higher in calories like avocados. Nutrical is a high calorie paste that can be purchased at pet stores or online to provided instant calories. They enjoy hot cereals such as oatmeal or cream of wheat prepared with milk, added fat such as butter or margarine. High calorie breads and straches include: quick bread (banana bread or zucchini bread), whole grain bread. Other high calories options are granola and cereals with dried fruit and nuts, cheese, crackers.
Low Sodium Diet - This is for rats who have certain health issues like congestive heart failure. Use low sodium lab blocks and only use fresh fruits and vegetables (no canned foods and check salt contient on frozen foods). Watch salt intake and cut out all salty, baked and processed foods as well as any dairy products. Use distilled water instead of tap water.

Homemade Diets
Homemade diets are non-commercial formulated diets that are implemented at home- whether you use a currently developed recipe or one you formulate yourself. A word of caution about these diets is that it is very difficult for one to ensure that they are complete in supplying all the nutrients needed.  Because of this, it is suggested that many of the homemade diets be supported buy providing add some lab block to it. It is also important that the dishes and bowls are checked to ensure that the rats are actually eating what they are given, not stashing. It is generally not suggested that owners try to implement a strictly vegetarian homemade diet or try to formulate their own diets. With any homemade diet, it is best to do your research and do not assume diets advertised on the Internet are necessarily a complete or suitable diet.
There are a a few pre-formulated homemade diets that are known online:
  • SueBee's Rat Diet - A very popular and well known homemade diet plan but is not considered a complete rat diet - use as a supplement with a staple diet already in place like Harlan lab blocks or Regal Rat by Oxbow.

Grain Diets and Dry Mixes
Grain mixes, also called dry mixes, are a type of homemade diet or supplement diet that center around using bulk grain ingredients, generally what you can find at a local supermarket. This diet is only suggested to be used in moderation with small servings and along with a staple lab block or rodent pellet. From my personal experience and research, I have found these mixes can be too high in carbohydrates,calories, sugars and should only be provided as a treat or 3 times a week at most or in very small servings. If you think about it, a Cheerio is about the size of a rat's paw. One Cheerio for a rat is like us eating a Cheerio the size of our hands - one would only eat one of these a day if that were the case. I have also found that the cheaper the product, the less in quality and quantity it is - so be sure to thoroughly compare the nutrition and essentials between brands. If you can afford it, I suggest buying top quality brands here. Once the ingredients are mixed, you will want to store in an air tight container in a cool, dry place. Suggested ingredients are:
  • Dry rolled oats (Brand: Quaker) - should be non-flavored. Do not overfeed as this is a binding food and can cause constipation
  • Puffed wheat cereal (Brands: Malt-O-Meal, Quaker or Kashi)- should be plain, unflavored and contain no sugar. Inexpensive and well liked. Cheerios can be used as an alternative but limit due to the added sugar content.
  • Puffed rice cereal (Brand: Quaker) - should be plain, unflavored and contain no sugar. Inexpensive and well liked.
  • Total Cereal - great source of vitamins and minerals that comes highly recommended by The Rat Fan Club
  • Soy Nuts - unsalted, roasted only. Great source of protein, vitamin K and helps ward of cancer.
  • Dried Fruits - Things like dried bananas, mango, cranberries, raisins (white and red), pineapple. Dried bananas should be just dried (Just Bananas) with no sugar added, not fried. This part of the mix can also be provided as a fresh fruit salad as a less expensive alternative. Fruit should make up a smaller portion of any diet or mix due to the sugar content of fruit but it should not be excluded in a diet either. Use with common sense and in controlled amounts.
  • Dry Pasta - provides carbohydrates, feed in moderation or limited. You may want to use healthy alternative pastas like tri-colored flavored pastas and wheat pastas.
  • Seeds & Nuts - Sunflower & pumpkin, should be unsalted and roasted, feed in limited amounts due to the amount of fat and protein added to the diet. Stay away from peanuts.
  • Muesli - Good alternative to the rolled oats, offers variety but use sparingly due to sugar content.

Diets Not Recommended
Seed Mixes - Generally, commercial seed and grain mixes are not recommended as these mixes contain too much corn, seed or filler ingredients. These mixes are generally not nutritionally complete and balanced as rats will tend to pick out the higher fatty contents that taste better and waste the rest. There have also been some reports of these mixes containing trace amounts of a pesticide called ethoxyquin which is known to cause cancer in humans as a preservative. The dried corn in these mixes can contain high levels of fungal contaminates, nitrates and amines which has been shown to cause liver cancer in rats and form nitrosamines which are carcinogenic in the stomach.
Dog/Other Pet Food Based Homemade Diets - A diet that is commonly tried but is not recommended are homemade diets based on dog food or other pet food as a protein source. Dog food, bird mixes, cat food, etc are nutritionally formulated specifically for that type of animal, not for rats. Because they are formulated for the metabolic needs of a completely different species they often contain incorrect levels of fat, proteins and important nutrients and do not provide a complete balanced diet. One particular issue with dog and cat foods is that these foods contain very high amounts of protein needed for a mostly carnivore type and has been known to cause skin issues, increased dominance/hormones and possible aggression issues in rats.
Unsupported Homemade Diets - A diet with a word of caution are homemade diets feed with no staple lab block or rodent pellet. It is critical that the right amount of nutrients and essential needs are meet in a complete and balanced way, thus this is not a suggested diet. These diets need to be implemented with caution and with daily observation and attention. It is suggested that owners keep weekly weight charts on each rat to ensure they are staying within a healthy weight range and closely monitor health, body condition and activity levels. When feeding the lose homemade diets, make sure that the rats are eating all of their food after each feeding. Do not top off bowls and remove any fresh foods that may spoil within 6 hours. When implementing a homemade diet, be sure to offer fresh fruits and veggies at the very least three times a week.
Unhealthy Foods -  This includes fried foods, greasy or oily foods, foods high in fat, sugar, calories, etc. Use common sense when deciding what youc an feed your rat- if a food is unhealthy for humans, its definately going to be unhealthy for rats.  Also, only a few healthy choice table scraps at day at most should be fed.

Food Storage
How long and at what temperature feed is stored before opening and use affect the nutrient quality of a diet. Most commercial feeds have a shelf life of 6 months but the longer feed is stored and if stored in a hot damp environment, nutrients within the feed will be lost. The duration of storage and the temperature at which feeds are stored prior to use affect the nutritive quality of diets. Commercial diets are formulated to have a shelf life of up to 6 months. Milling dates should be identified on bags and containers to ensure freshness. Store feed bags in a cool, dry area with temperatures less than 64 F, store on pallets (off the ground) if possible and away from strong-smelling products such as oil or disinfectants. Blocks can also be frozen in airtight Ziploc bags for a longer shelf life. Harlan Teklad lab blocks have a shelf life of six to eight months if kept in the freezer.

Interesting Facts
  • Rats do not need a salt nor a mineral lick as these are provided in their complete diet. Salt licks are only needed by strict herbivores.
  • A rat's body will generate all the vitamin C they need - only Guinea pigs and primates must get their vitamin C from a food source.
  • Rats cannot vomit or burp due to a flap in their stomach that covers the esophagus. Because of this, according to the Rat Guide, veterinarians (for most surgical procedures) do not require that you withhold food or water prior to surgery. An exception to this may be when surgery involves the gut or abdomen, and even then withholding food or water should be of short duration due to their rapid rate of metabolism.
Table 1 ~ Suggested Daily Menu
Daily Vegetable
(choose 3 for each day)
  • Kale
  • Broccoli
  • Bok Choy
  • Peas
  • Sprouts
  • Tomato
  • Squash
  • Carrot
  • Parsley
  • Sweet potatoes
  • Corn (only feed once a week)
Daily Fruit
(choose 1 for each day)
  • Berries
  • Banana
  • Grape or raisin
  • Plum or prunes
  • Apple
  • Melon
Daily Protein/Legumes
(choose 1 for each day)
  • Beans (cooked)
  • Liver (cooked, unseasoned)
  • Lean meats (cooked)
  • soy/almond/rice milk
  • tofu (cooked)
  • soy yogurt
  • TVP (textured vegatable protien)
Daily Staple
  • Quality lab block
I chose to separate this section out and go into detail specifically about lab blocks as this has become the most widely accepted staple diet for rats both in the lab and in our homes. However, many commercial manufactures and mills have picked up on this and are making their own formulated blocks for sale on the market. Realizing that not all blocks are created equally and knowing which block is best can be difficult. Also, an emerging wave of manufactures and mills are coming up with similar rodent pellets to meet the market needs of a complete fortified commercially available rodent food.
The general rule of thumb by which to determine block suitability is by the protein % and the main ingredients. It is now generally believed that the percentage of protein of a block should be kept at 14% - 18% for a regular maintenance diet for an adult rat not actively in a reproductive cycle or later years cycle. For those in an active breeding cycle or in the early development years cycle, the percentage should be a minimum of 18% to about 22%. The main ingredients (listed first on the nutrient bars or each block) should be either soy or wheat, not corn which is a fatty filler. There are some indications that rat feed a diet high in soy may be less prone to mammary tumors and decrease pain perception, though this soybean meal is not as beneficial for males it seems but a staple diet of a 14% protein block is best for older males.
Lab Blocks and Rodent Pellets
Things to Feed in Moderation-
  • plain popped popcorn
  • Vitakraft yogurt drops
  • avocado
  • chocolate
  • chicken or beef bones (cooked or boiled)
  • Kaytee chew biscuits
  • fruit Nutra*Puffs
  • vegetable Nutra*Puffs
  • dried corn
  • Nylabones for chewing
  • Foods high in nitrates: beets, celery, eggplant, lettuce, cucumber,
  • radishes, spinach, collards and turnip greens
  • coffee
  • soy *there is some contraversy with how much soy is too much for rats, I have personally choose to moderate the amounts but not to totally remove from the diet as it is still out for debate and is a useful source of substitute protein.*

Table 2 ~ Restrictive and Special Foods
Things To Never Feed-
  • carbonated/fizzy drinks
  • foods (in excess) that cause gas
  • Orange Peels/Orange Juice (for males) - Pieces of the orange "fruit" are okay after washing
  • raw dry beans/Peanuts (contain anti-nutrients that destroy Vit. A
  • & digestion enzymes, causes red blood cell clumping)
  • raw sweet potato
  • green bananas (inhibits digestion of starch)
  • green potato skin and eyes (contains a toxin)
  • wild insects
  • raw bulk tofu
  • moldy cheese
  • licorice (suspicions of neurological poisoning)
  • raw red cabbage (contains anti-nutrients that destroys thiamin)
  • raw artichokes (inhibits digestion of protein)
  • raw oysters/clams 

This page was last updated: May 18, 2011