Leafy greens are super healthy, right? But then again – you may have heard words of caution against feeding your rats spinach.
So, is spinach safe for pet rats? Should it be fed raw or cooked? And is it true that spinach can cause kidney problems in rats?
Spinach does contain a lot of oxalates, which can cause kidney stones when consumed in large amounts. In healthy rats, feeding a bit of spinach occasionally is not an issue. In fact, spinach has a lot of health benefits!
If you want to find out how much spinach is safe, and what is the best way to prepare it – we’ve summed the research up for you.
Can You Feed Spinach to Your Pet Rat?
Is Spinach Safe for Rats?
Spinach is about 90% water1. Other than that, it consists mainly of fiber. The insoluble fiber contained in spinach can help regulate digestion and the gut microbiome2. Sugars are present in pretty much negligible amounts in spinach.
Spinach boasts a few great micronutrients, such as vitamin A (or, more accurately, its precursors), vitamin K1, and vitamin C3.
There’s also a substantial amount of iron in spinach, as well as calcium for bone health. Both calcium and iron, though, show a lower bioavailability in spinach than in meat products, which means that even though spinach contains a lot of these nutrients on paper, not all of them can be absorbed and utilized by the body4,5.
Still, spinach boasts quite an impressive list of health benefits. It is one of the richest dietary sources of quercetin, a plant compound that decreases inflammation and reduces the risk of cancer6,7. Similar health effects have been shown for kaempferol8.
Lutein and zeaxanthine contained in spinach are linked to improved eye health9. Spinach also contains nitrates, which are good for the heart and vascular system10.
A study performed on hyperlipidemic rats (rats whose bloodstream shows elevated levels of fats) showed that consumption of spinach was linked to antioxidant effects, which helped counteract the negative effects of fat metabolism in the liver11.
These are plenty of good reasons to feed spinach to your pet rats. But what about oxalates and kidney stones, you may ask?
Can Spinach Cause Kidney Stones in Rats?
Spinach contains oxalates. Oxalates are mainly excreted through urine and can accumulate in the urinary tract and form kidney stones12,13.
For this reason, some people will recommend that you completely omit spinach from your rat’s diet. However, there is a grey area.
Just like healthy people can eat copious amounts of spinach without developing kidney stones, a healthy rat will not develop kidney problems if fed a little bit of spinach here and there.
It’s important to look after your rat’s bladder health in different ways: Always offer plenty of fresh, clean drinking water, keep your pet rats at a healthy weight, and make sure that they get plenty of exercise.
If these factors are a given, and if no previous kidney issues are present in your rats, you can feed them a bit of spinach without having to worry. One or two small leaves – or a teaspoon of cooked spinach leaves – per rat once a week is fine.
Can Rats Eat Spinach Stems?
Oxalate contents are actually lower in the stems than in the leaves of spinach14. You can leave the stems on when feeding spinach to your rats.
Older, tougher stems will probably not be very palatable, and your rats might not eat them.
Is Raw or Cooked Spinach Better?
Boiling can reduce oxalate contents by 30-87%15. If you’re worried about your rat’s kidney health, offering boiled spinach is the better alternative.
Steaming is not quite as effective, interestingly.
Generally, leafy greens are very healthy for your rats. Rocket, Swiss chard and kale are all great foods to offer your mischief.
You can experiment to see if your rats prefer their leafy greens cooked or raw.
What Vegetables are Poisonous to Rats?
Some foods should be avoided altogether, and some should only be fed cooked.
Vegetables that should never be fed raw include: Artichokes, beans, potatoes, and sweet potatoes. When cooked, these are all perfectly healthy foods for your pet rats.
Raw cabbage is fine in moderation, but too much can cause bloating and gas.
Although it’s technically a fruit, many people think of avocado as a vegetable. Avocado is safe for your rats to eat, but be sure to remove the skin and the pit.
If any of your rats have a chronic health issue, make sure to check with your veterinarian if there are any specific foods that should be avoided.
To Sum Up
Although it’s often said to avoid it altogether, spinach is perfectly fine for rats in small amounts. It actually boasts a lot of health benefits!
If you’re worried about oxalate content, offer boiled spinach instead of raw or steamed.
Avoid spinach for rats with pre-existing kidney conditions.
1. U.S. Department of Agriculture. FoodData Central – Spinach, mature. 2021. https://fdc.nal.usda.gov/fdc-app.html#/food-details/1999633/nutrients.
2. Bourquin LD, Titgemeyer EC, Fahey GC, Jr. Vegetable fiber fermentation by human fecal bacteria: cell wall polysaccharide disappearance and short-chain fatty acid production during in vitro fermentation and water-holding capacity of unfermented residues. J Nutr 1993;123:860-869. https://pubmed.ncbi.nlm.nih.gov/8387579/.
3. Tang G. Chapter 25 – Spinach and Carrots: Vitamin A and Health In: Watson RR,Preedy VR, eds. Bioactive Foods in Promoting Health. San Diego: Academic Press, 2010;381-392.
4. Heaney RP, Weaver CM, Recker RR. Calcium absorbability from spinach. Am J Clin Nutr 1988;47:707-709. https://pubmed.ncbi.nlm.nih.gov/3354496/.
5. Zhang D, Hendricks DG, Mahoney AW. Bioavailability of total iron from meat, spinach (Spinacea oleracea L.) and meat-spinach mixtures by anaemic and non-anaemic rats. Br J Nutr 1989;61:331-343. https://pubmed.ncbi.nlm.nih.gov/2640540/.
6. Stewart LK, Soileau JL, Ribnicky D, et al. Quercetin transiently increases energy expenditure but persistently decreases circulating markers of inflammation in C57BL/6J mice fed a high-fat diet. Metabolism 2008;57:S39-46. https://pubmed.ncbi.nlm.nih.gov/18555853/.
7. Murakami A, Ashida H, Terao J. Multitargeted cancer prevention by quercetin. Cancer Lett 2008;269:315-325. https://pubmed.ncbi.nlm.nih.gov/18467024/.
8. Chen AY, Chen YC. A review of the dietary flavonoid, kaempferol on human health and cancer chemoprevention. Food Chem 2013;138:2099-2107. https://pubmed.ncbi.nlm.nih.gov/23497863/.
9. Krinsky NI, Landrum JT, Bone RA. Biologic mechanisms of the protective role of lutein and zeaxanthin in the eye. Annu Rev Nutr 2003;23:171-201. https://pubmed.ncbi.nlm.nih.gov/12626691/.
10. Bondonno CP, Yang X, Croft KD, et al. Flavonoid-rich apples and nitrate-rich spinach augment nitric oxide status and improve endothelial function in healthy men and women: a randomized controlled trial. Free Radic Biol Med 2012;52:95-102. https://pubmed.ncbi.nlm.nih.gov/22019438/.
11. Ko SH, Park JH, Kim SY, et al. Antioxidant Effects of Spinach (Spinacia oleracea L.) Supplementation in Hyperlipidemic Rats. Prev Nutr Food Sci 2014;19:19-26. https://pubmed.ncbi.nlm.nih.gov/24772405/.
12. Knight TF, Sansom SC, Senekjian HO, et al. Oxalate secretion in the rat proximal tubule. Am J Physiol 1981;240:F295-298. https://pubmed.ncbi.nlm.nih.gov/7223887/.
13. Massey LK, Roman-Smith H, Sutton RA. Effect of dietary oxalate and calcium on urinary oxalate and risk of formation of calcium oxalate kidney stones. J Am Diet Assoc 1993;93:901-906. https://pubmed.ncbi.nlm.nih.gov/8335871/.
14. Elia A, Santamaria P, Serio F. Nitrogen nutrition, yield and quality of spinach. J Sci Food Agr 1998;76:341-346. https://onlinelibrary.wiley.com/doi/10.1002/(SICI)1097-0010(199803)76:3%3C341::AID-JSFA938%3E3.0.CO;2-4.
15. Chai W, Liebman M. Effect of different cooking methods on vegetable oxalate content. J Agric Food Chem 2005;53:3027-3030. https://pubmed.ncbi.nlm.nih.gov/15826055/.
Nina has a degree from the Veterinary School in Zurich, with a special focus on microbiological research. Nina has a passion for sports, nutrition and the outdoors and she loves all pets, but rats have a special place in her heart. When she’s not working or reading and writing about all things related to pet health, she loves to travel and surf.
As a small animal veterinarian, Nina is your go-to expert on pet health and nutrition.