But, it is really hard to know whether those new kinds of foods are good for your pet. However, remember that all the available fruits that are nutritious for us may not be recommendable for your pets. Watermelon is one of those fruits that guinea pig owners generally choose to offer their furry pets. There are different views on the issue- Can guinea pigs safely consume watermelon? In the following article, you can find information on how watermelon can benefit your pet and how much amount of the fruit is to be given to your cavy. Watermelons are harmless for your guinea pig as it contains a huge amount of water.