Yes, you can. Carrots are essential when it comes to the teeth, they control the alignment and grow of your cavy's teeth. However, the liver of the guinea pig is very delicate and excessive feeding of carrot may cause liver problems. Guinea pigs consume different vegetables and they break down all the minerals and vitamins specially C and A if they have the appropiate amount of vitamin A, and you feed an extra every day, it could lead to excessive vitamin A, and might damage the piggy's liver. Please feed your cavy carrot every 3-4 days, to keep them healthy.