Nutrition and safety of celtuce leaves (a-choy)

[AviN4]

After several months of empty nest syndrome, my wife and I adopted 3 female guinea pigs in July 2025, Stevie, Carli, and Frankie. We prefer to order groceries online, but it's been an ongoing struggle to consistently acquire green leaf or red leaf lettuce. At times, celtuce leaves, a cultivar of lettuce also known as a-choy, are more readily available and/or less expensive for us. I've reviewed the nutritional content of celtuce, and it does seem appropriate for guinea pigs, comparable to green leaf lettuce. We've fed celtuce leaves to the trio and they usually devour it within minutes. However, I still have a few concerns:

1. I am aware of anecdotes that romaine lettuce causes calcium deposits in urine, even though there's nothing in romaine lettuce nutritional information that explains it. Does anyone know whether this may apply to celtuce leaves too? With the paper bedding we use, it's difficult for us to see what's coming out of their urine.
2. I'm unsure if the USDA nutritional information about celtuce refers to the large edible stem, the leaves, or some kind of average of the entire plant. I also haven't been able to find any other reliable sources with detailed nutritional information.

Does anyone have any experience or knowledge about the nutrition and safety of feeding celtuce leaves to guinea pigs?

[Lynx]

Congratulations on adopting three guinea pigs! I think that is a good number - and hope they get along well and live good healthy lives!

I was completely unfamiliar with this veg. Glad you found info on the USDA website.

My first question was if it might cause gas. That does not seem to be an issue. Asking questions about calcium excretion is reasonable. Leaving deposits on heavy cotton cloths was how I made the romaine connection. You may have to experiment yourself to get an answer.

For me, the piles of calcium deposits showed up perhaps an hour after eating the romaine. Later the urine turned clear.

Let us know what you find out.

[Renonvsparky]

I can only speak to my experience with romaine lettuce. I use fleece bedding with wood bedding pellets underneath, so it's very easy to see if there's an issue with their urine. My younger guinea pigs didn't seem to have issues with romaine lettuce causing calcium deposits, while the older ones did. It started somewhere around the 3 year old mark. I've tried a few types of lettuce, including what I've grown for them in my greenhouse. Bibb, Simpson, savanna and different mixes. None of them caused any issues and the guinea pigs of all ages loved them.

If you have the means, I highly recommend growing your own lettuce. With a greenhouse, you can grow year round. Mine are 10 by 30, 10 by 20 and 9 by 16 foot. If you're challenged for space, they have those small ones that can go pretty much anywhere. Sorry I can't be of more help.

[Sef]

I don't know anything about that lettuce. We feed green leaf and butter/Boston lettuce. An idea to help track calcium deposits on paper bedding is to have a small area with some fleece that they can sleep on/pee on.

[Lynx]

I second Sef's suggestion of using a small area of fleece (dark material helps the calcium deposits stand out).

[AviN4]

Thanks all for the suggestions. We'll try to run an experiment this weekend and report back with any findings.

[AviN4]

We gave the 3 guinea pigs a lot of celtuce leaves throughout the day, placed them all on darkish gray towels outside the cage, and gave them even more celtuce leaves to encourage urination. My wife told me she observed them urinating a lot. Among the 3 towels, we were able to find many wet areas, but only 2 small spots in those areas with white residue.



This doesn't seem like a lot of white to me, but I'm not sure?

We could try a control experiment with green leaf lettuce next week.

We could also try again with an even darker towel or other cotton cloth. We'd have to see what we have or if we need to buy something for the experiment.

[Lynx]

If they were on these towels for several hours and got a bunch of celtuce, that sounds like a decent experiment and it appears this veg will likely not be a problem.

[AviN4]

Oh, it was only for about 30 min, while I was cleaning their cage. So maybe it wasn't long enough.

[Lynx]

I think you need a longer test period then. Say you give them several leaves and within 15 minutes or so put them on the towels for a minimum of an hour. Wet leaves. Ideally it would be longer (unsure precisely how long transit time would be).