Feta is a brined curd white cheese made in Greece from sheep’s milk or from a mixture of sheep and goat’s milk.
Similar brined white cheeses produced in Europe are often made partly or wholly of cow’s milk, and they are sometimes also called feta.
It is a crumbly aged cheese, commonly produced in blocks, and has a slightly grainy texture.
Feta is used as a table cheese, as well as in salads (e.g. the Greek salad) and pastries.(source)
Can guinea pigs eat feta cheese?
Unfortunately, they can’t eat any kind of dairy product. It is just too much for their stomach and will make them sick if they eat it.
A food to avoid feeding them.
For more foods that guinea pigs can and can’t eat check out our guinea pig food. List