Cats cannot eat oranges
1. Do not feed oranges to cats. Cats dislike the smell of orange peel, and the orange flesh also has some of the peel's smell, so oranges are not a favorite food for cats. Owners can try peeling an orange next to their cat. When the cat smells the orange peel, it will usually squint, back away, and then run away.
2. The essential oils in oranges can irritate a cat's stomach and intestines, causing discomfort and, in severe cases, vomiting and diarrhea. If your cat has eaten citrus fruits, carefully observe its condition. If it exhibits any adverse reactions, take it to the vet immediately for examination. 
Orange's undesirable behavior towards the cat is as follows:
While oranges may be beneficial to humans due to their high vitamin C content, it's a completely different story for cats. The essential oils in oranges are toxic to cats, so they should absolutely be avoided. Cats that eat oranges can experience very severe diarrhea. They may also begin vomiting because the citric acid in oranges disrupts their stomachs. In some cases, eating oranges has actually been shown to cause depression in cats and even lead to hypersensitivity to photosensitivity.
