Can my guinea pig eat only romaine lettuce daily with other veggies?

You should feed about one cup of fresh vegetables for each guinea pig every day. Leafy greens vegetables like romaine lettuce, spinach, kale or parsley are the best. Add carrots, baby tomatoes, zucchini and sweet potato a few times a week. Fresh vegetables provide them with a wide range of essential vitamins and minerals, including vitamin C.

It's OK for him to eat spinach everyday, but it should not be a major component of his diet, because it is too concentrated. The major component of his diet should be a high fiber pellet and high quality hay. Fruits and vegetables are also good to give on a daily basis, but they should not be the majority of the food he is eating. It's best to have variety, but if he has a few leaves of spinach each day, then I see no problem with that. I hope that helps and all is well with Mellow.

I do not think the pellets are bad but should be given in moderation. These are high in fat and can cause obesity. I recommend a large amount of roughage like Timothy hay all day long with moderate amount of veggies and small amount of pellets. The roughage is really good for their teeth too.

Fresh grass along with some green vegetables are a fine substitution for most small herbivore species like guinea pigs and rabbits, but any food change must be done gradually to avoid diarrhea. If you can get fresh grass year-round, this is a fine option, but make sure to stay away from legumes like alfalfa as this is too fattening for guinea pigs long-term and should only be used as a treat. Don't forget to add vitamin C either to the water or as a food supplement as this is required for pigs!

Hay is not a bad diet for guinea pigs but the do have an absolute requirement for vitamin C - this can be from vegetables/fruits (sych as peppers, dark leafy greens, brocolli or squashes), supplemented pellets or in Rose's case vitsamin C srops for her water may be helpful also

This article should clarify things for you: ( https://www.petcoach.co/article/the-best-way-to-care-for-and-feed-your-guinea-pig/ ) The diet should be mostly hay (Timothy) and only a very small amount of pellets and other foods. ( https://www.amazon.co.uk/Petlife-Oxbow-Western-Timothy-Small/dp/B000WFKF9O/ref=sr_1_3?crid=36258PZZT5VOO&keywords=oxbow+hay+timothy&qid=1557744772&s=gateway&sprefix=oxbow+hay%2Caps%2C773&sr=8-3 ) ( https://www.amazon.co.uk/Petlife-Cavy-Cuisine-Complete-Guinea/dp/B0017JFIDC/ref=sr_1_1?keywords=oxbow+pellets&qid=1557744806&s=gateway&sr=8-1 )

They need approximately 10mg of Vitamin C a day. It is best to give them through fresh fruits and vegetables. Below are some suggested serving sizes of foods that are high in Vitamin C. These serving sizes provide approximately 10mg of Vitamin C. Green Bell Peppers - 1/7 of a pepper Kale - 1/8 cup Kiwis - 1/8 cup Parsley - 1/8 cup Red Bell Peppers - 1/14 of a pepper Oranges - 1/7 of a fruit (~2-5/8 inch diameter fruit) I hope this helps!