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Surprisingly Safe and Unsafe Rat Treats

An Explanation

Rat digestive systems differ greatly from dogs, cats, rabbits, and other animals. This allows rats to eat things they can not. However, some foods are still toxic. Knowing what your rat can and can not have is lifesaving.

Safe Rat Treat Giving Practice

Keep in mind while these foods are safe for your rat to eat, moderation is key. Too much of anything is bad for you, and this goes for your rats and mice as well. I wrote this article with the intention of these foods being used as treats only. Limit foods which are very fatty, high in sugar, or otherwise unhealthy.

Rat Treat Cross Contamination

Dog doing research
I’m reading up on how to take the best care of my human.

Do a mental check if you are thinking of giving your pets something off your plate. What are all the ingredients in this food? Are any of those ingredients toxic? Is there a potential of cross contamination from something else on my plate which is toxic for them? If something harmful may have touched otherwise safe food for that species of animal, don’t risk it. Rats are much smaller, and it takes much less of something bad before it harms them.

With dogs, if they get into something like THC or chocolate but it’s only a little, they can be monitored and might not need a vet visit depending on what your vet says during the phone call. But with small animals, like rats with garlic, there is a higher amount of toxin by ratio of weight to them, and that margin for error is too small to risk. The smaller the pet by weight, the less of a toxin it takes to harm them. Always err on the safe side, because there will be better opportunities to give your pets a treat.

A Healthy Main Diet

Ensuring your rats live a long, healthy life requires a healthy daily diet of a food block or moderated food mix, with fasting aiding an increased lifespan. Making your own mix takes more than balancing protein, fat, and fiber. If all micronutrients like iron, magnesium, and many others are unbalanced as well, your pets could get sick from too much or too little of something in their diet. I do not condone or recommend using this list to make your own mix.

Surprisingly Safe Rat Treats

Some foods they can eat may be surprising, because most are not safe for many other animals. However, rats are different, allowing them to chew and digest in ways which allow them to enjoy these foods as well.

Bones

Rats can have all bones, raw and cooked, because of how they chew. Instead of bones being crushed and swallowed in sharp chunks, they are powderized by a rat’s powerful jaws. This eliminates any chance of bowel perforation, which would be a concern with cats and dogs. 

Chocolate

Rats can not only have chocolate, but it can be good for them in certain situations. Peruvian dark chocolate has some evidence of helping your rat(s) with respiratory infections by opening airways. Keep in mind milk chocolate is still high sugar, and should only be an occasional treat.

Dairy

Most cheeses are safe rat treats. The rat got the cheese on this one! Rats and some other rodents, like hamsters and mice, are not lactose intolerant. Milk, many cheeses, dairy-based treats, and more are all okay!

My research on this one makes a good point in moderation, however. While rats can tolerate up to 25% lactose just fine, 30% is too much. Note this study fed 30% lactose in their diet daily for an extended period you typically would not see in a pet keeping situation. Don’t feed your rats a lot of dairy every day, as it is poorly digested in high, prolonged amounts. According to page two of a study by Riggs and Beaty, rats showed pot bellies and/or diarrhea when fed a diet of 30% or more lactose, but showed no negative symptoms with a diet containing no more than 15% lactose.

Citrus

To some, the fact rats and other rodents can have citrus may be surprising, because a scientific study suggesting it is toxic to them gained popularity. However, this scientific experiment gave rats so much citrus that if humans ate the same ratio amount by weight, we’d get sick from it, too! All the study proved is something we already know; too much of anything is bad for you. 

Fortunately, science can be self correcting. Since then, more scientific studies have published data showing citrus is nontoxic, even at relatively high concentrations. So lemons, oranges, pineapples, grapefruit, limes, and other citrus are still on the menu. 

Garlic, Onion, and Other Alliums

Onions are unsafe rat treats when given too much or too often. Most animals can get anemic (have low blood cell count) if they eat too much of a plant from the allium family. However, rats can have small amounts of raw and cooked onions with no issue. The breeder, Isamu rats, specifies only 1 tsp of raw onion or 1 garlic clove, with more being tolerated if they’re cooked.

Garlic and onions have some health benefits when fed to rats, however, those benefits become adverse effects when fed too much or too often. More research is necessary to determine at what dose this flip occurs, but for now, feeding occasionally in small amounts is probably okay.

Safe Foods

If I were to make a complete list of this, it would be as long as a chapter book. Rats can have most foods humans can. However, this does not make all of those foods good for them. Therefore, it is important to avoid unhealthy foods except on special occasions (birthdays and last days) to ensure your rat has a long, healthy life. 

Do not take this paragraph as an excuse to feed your rat whatever without checking, however. Humans can eat some things rats can not, and some are common.

Unsafe Foods

I do not mean this unsafe foods list to cover everything. The best advice I can give you is to never assume something is safe for your pet. If it is a product from the store, read all the ingredients. Read the spice mix labels and take mental note of everything in it before giving a food you made to your rats. If you’re not sure about the food item, look it up and don’t take the first answer in google as fact. Never assume or guess it will be okay. 

Don’t fall into dangerous assumptions like mint is okay, so catnip is too, because it is also in the mint family. Catnip is toxic to rats. Many plants and foods are related, but one can be toxic where the other is not. One example is tomatoes and deadly nightshade, both in the nightshade family. The only part of a tomato plant which is edible is the tomato itself. The roots, leaves, and stem of a tomato plant are toxic. With deadly nightshade, the entire plant is toxic. 

If the food is not toxic, think of other ways it could be a hazard. Is it sticky and gummy, like peanut butter? Is it soft and moldable, causing potential for choking, like soft bread? Should you limit how much you give due to sugar and/or fat content? The more you know, the safer your pets are.

Catnip

When looking for toys and treats made for other species to give to rats, avoid anything with catnip in it. The effect of catnip on rats is much stronger and more sedative, with detrimental effects like increased susceptibility to seizures.

Licorice

Licorice contains neurotoxins in significant enough amounts to harm your rat’s brain and should be avoided. 

I believe it is important to note, most black licorice you can buy today is made with anise because real black licorice is toxic in amounts low enough to be accidentally over-ingested by humans. Licorice lowers potassium in the body, causing heart issues and heart failure in high enough doses. In humans, 2 ounces per day every day for 2 weeks is enough to cause heart arrhythmias in people over 40 years old. However, some foods do still have real black licorice. With symptomatic amounts being low enough to cause symptoms bad enough to put a human in the hospital on accident for licorice lovers, an overdose in a rat is likely also very easy.

Moldy, Soured, or Expired Foods

Rats have a reputation of being disgusting things who eat anything off the streets, out of dumpsters, ext… While wild rats will eat whatever is available to survive, and in cities it often is human trash, this diet is still not safe or ideal for them. If it is not something you would eat yourself because of an off smell, mold, or anything else, don’t give it to your rats. Yeah, they might eat it, but they can’t vomit, and they can get sick from the toxins mold creates. They’re trusting you to give them good food. In fact, many baby rats rely on instinct. With every unfamiliar food, they will eat a tiny piece, wait a few hours, and if they still feel okay, they will eat some more. But they will gain trust as they get to know you and none of the foods you give make them sick. Eventually, they will take a new food from you and eat it without pause.

Blue-Veined Cheeses

Blue cheese on wooden board with assorted nuts scattered around.
Do them a solid and pass on this one.

As I was doing my research, I found blue cheese on multiple lists of toxic foods for rats, with no explanation why. So, I did some more digging and found a scientific article. An important thing to add, which many articles left out, is the mold used in the cheese’s creation is the problem, not the cheese itself. The mold, called Penicillium roqueforti, produces mycotoxins and is also found in gorgonzola, danablu, gorgonzola, stilton, and roque-fort cheeses. 

What Science Says

The study says blue cheese contains mycotoxins, like PR toxin, botryodiploidin, penicillic acid, isofumigaclavin C, roquefortine, and Patulin. PR toxin has notable amounts during processing. Of these, PR toxin is the most concerning, causing slowed breathing, abdominal writhing, loss of coordination, paralysis, hind leg paralysis and/or weakness, stumbling, and clumsy movements. Liver, heart, brain, and other damage can also occur.

Companies often age blue cheese 90 days before being packaged for sale. The aging process significantly depletes PR toxin, being almost entirely gone by 120 days of aging. However, PR toxin is not regulated in food or production, as quoted in another study, “Since, the level of this mycotoxin in food and feed products are not regulated, the contamination of P. roqueforti in grass silages, grains, or other food and feedstuffs could have a safety risk, and could not be deteriorated using normal cooking processes, therefore, potentially have both health and economic impacts.” What it decays into, PR acid and PR-imine, are still unsafe, although less so. Cooking also does not affect its deterioration in the cheese. Even with PR toxin depleted after 120 days, the other mycotoxins left, and the toxins created from the decay of PR toxin are still concerning enough to side with caution and avoid feeding hard blue cheeses ripened with P. roqueforti.

Wild Bugs

Rats are opportunistic predators. If a bug gets into their cage and they catch it, they’ll eat it… However, catching and feeding your rats wild bugs is risky. Wild bugs can carry parasites and disease. Some are venomous or toxic by nature. If you want to feed your rats insects, get dubia roaches, crickets, mealworms, super worms, or ext… from the reptile section of the pet store.

Conclusion

A rat’s digestive system is different from a cat’s or a dog’s, allowing them to eat many things they can’t. Bones, chocolate, dairy, grapes, raisins, citrus, and more are all safe for your rat to eat in reasonable amounts. However, rats are not bombproof, nor are they trash disposals. If you wouldn’t eat the food because of its quality, don’t give it to your rat, and don’t feed them wild bugs. While many foods are fine, licorice, catnip, and blue-veined or moldy cheeses are toxic and should be avoided. Always err on the side of caution with foods you aren’t sure about. You’d rather your rat miss out on one opportunity for a treat than get sick and suffer from something harmful.

APA Formatted References For Scientific Articles

(1997). Attachment I–final Risk Assessment Penicillium Roqueforti.

Carlson, A. J., & Hoelzel, F. (1946). Apparent prolongation of the life span of rats by intermittent fasting. The Journal of nutrition, 31, 363–375. https://doi.org/10.1093/jn/31.3.363

Atkinson, R.L., Kratzer, F.H., & Stewart, G.F. (1957). Lactose in animal and human feeding: A review. Journal of Dairy Science, 40(9), 1114-1132. https://doi.org/10.3168/jds.S0022-0302(57)94603-9

Gałęcki, R., & Sokół, R. (2019). A parasitological evaluation of edible insects and their role in the transmission of parasitic diseases to humans and animals. PLoS One, 14(7), e0219303. https://doi.org/10.1371/journal.pone.0219303

Massoco, C. O., Silva, M. R., Gorniak, S. L., Spinosa, M. S., & Bernardi, M. M. (1995). Behavioral effects of acute and long-term administration of catnip (Nepeta cataria) in mice. Veterinary and human toxicology, 37(6), 530–533.

Najman, K., Leontowicz, H., & Leontowicz, M. (2021). The Influence of Plants from the Alliaceae Family on Morphological Parameters of the Intestine in Atherogenic Rats. Nutrients13(11), 3876. https://doi.org/10.3390/nu13113876

Omar, H. R., Komarova, I., El-Ghonemi, M., Fathy, A., Rashad, R., Abdelmalak, H. D., Yerramadha, M. R., Ali, Y., Helal, E., & Camporesi, E. M. (2012). Licorice abuse: time to send a warning message. Therapeutic advances in endocrinology and metabolism3(4), 125–138. https://doi.org/10.1177/2042018812454322

Oyebadejo, S. A., & Solomon, I. P. (2019). Toxicological Evaluation of Citrus Limon Juice on Sprague Dawley Rats: Acute and Sub-Acute Studies. East African Scholars Journal of Biotechnology and Genetics, 1(2), 25-32.

Périz, M., Pérez-Cano, F. J., Cambras, T., Franch, À., Best, I., Pastor-Soplin, S., Castell, M., & Massot-Cladera, M. (2020). Attenuating Effect of Peruvian Cocoa Populations on the Acute Asthmatic Response in Brown Norway Rats. Nutrients12(8), 2301. https://doi.org/10.3390/nu12082301

Polonelli, L., Morace, G., delle Monache, F., & Samson, R. A. (1978). Studies on the PR toxin of Penicillium roqueforti. Mycopathologia, 66(1-2), 99–104. https://doi.org/10.1007/BF00429600

Van de Heijning, B. J., Kegler, D., Schipper, L., Voogd, E., Oosting, A., & van der Beek, E. M. (2015). Acute and Chronic Effects of Dietary Lactose in Adult Rats Are not Explained by Residual Intestinal Lactase Activity. Nutrients, 7(7), 5542–5555. https://doi.org/10.3390/nu7075237