Cats can eat cucumbers safely in small amounts. Cucumbers are non-toxic to cats, low in calories, and mainly composed of water, which can provide hydration. However, cucumbers do not offer the essential nutrients cats need as obligate carnivores, so they should only be an occasional treat and not a regular part of their diet. It is also recommended to peel the cucumber before giving it to cats to reduce fiber intake that might upset their digestion. Pickled cucumbers or cucumbers with added seasonings should be avoided due to potential toxicity or digestive issues. Overall, a small slice or two occasionally is considered safe and can be a crunchy, hydrating snack for cats.