If you've been following the posts here on Facebook, you probably know that I feed a variety of mixed veggies each day, and sometimes fruit detailed in "Today on the Menu." Veggies are an important part of guinea pig health, to supplement the additional Vitamin C your guinea pig needs. I particularly choose things that are high in Vitamin C, like bell peppers, to feed each day. Choosing your guinea pigs daily menu is a bit more complicated when you dig into it, and I actually put a good amount of thought into the selections I make. I'm going to share what I know here and try to keep it simple.
First, you should know about Oxalic Acid (oxatales) which are commonly present in the veggies we and our guinea pigs eat. It is a natural chemical that can become toxic at high levels. At normal levels, people and animals will pass it in urine without issues. Guinea pigs, especially those with a history of urinary complications, can have probelms with oxatales crystallizing. Kidney stones may occur. Since prevention is best, I limit foods that are high in Oxalic Acid. Young veggies, like baby spinach or baby carrots, will have a smaller amounts of Oxalic Acid than more mature veggies.
Calcium is something else that you need to keep in mind. It is important to all life, however too much of it can also create bladder stones. If your guinea pig is prone to urinary blockages, you should monitor calcium and oxalic acid in the diet carefully.
Vitamin C, as mentioned above, is very important to guinea pigs. This is because they cannot create it within the body, so pick veggies that are good sources. The fresher your veggies are, the better the vitamin content will be. When the leaves turn yellow, it's doubtful they hold much nutritional value and should be tossed.
Fruits are very much appreciated by your guinea pigs as treats, but they are high in sugars and should be fed in moderation.
Keeping in mind all of this information, I look for foods that are high in Vitamin C, and fairly low in calcium and oxalic acid for my daily staples. These are my favorites:
#1. Bell Peppers - green, yellow, orange, or red. The more orange/red they are, the more vitamin C they carry but also contain more sugar. I rotate feeding different color varieties.
#3. Romaine lettuce, red or green leaf lettuce, butterhead lettuce, or other lettuces
#4. Kale - red or green, fed a little less often than the lettuce varieties above
#1. Baby spring mix - these baby greens are likely to have lower amounts of oxalic acid
#2. Green seedless grapes - generally lower sugar than the sweeter purple kinds, and my pigs love them! I usually only give one or two grapes per guinea pig weekly and they're chopped in half.
#3. Green apples - also lower in sugar generally than the sweeter red varieties, and my guinea pigs love them too! I chop the slices up into smaller pieces and limit how much they get each week.
#4. Parsley - given in smaller portions due to high oxalic acid, but this is also very high in Vitamin C
#5. Carrots - not great for nutrition, but my guinea pigs love them, so I offer a small amount a couple times a week, keeping in mind it's high in oxalic acid. Here's why I don't buy baby carrots.
#6. Baby spinach - high in vitamin C, but also high in oxalic acid and calcium so I feed a couple times a month in smaller amounts. Baby spinach should be slightly lower in oxalic acid.
#7. Cucumber - not a great source of nutrition, contains some oxalic acid, but the pigs love it so it is fed in moderation too.
They key to feeding is variety and moderation. Your guinea pigs love trying new things and are excited to see what's coming next. If you'd like to know what veggies contain what, the charts on Guinea Lynx are phenomenal, in fact, you should check out the entire site if you haven't already.
I hope this helps simplify your menu choices.