Cats can certainly eat grapefruit pulp. Grapefruit pulp is very nutritious and can help supplement vitamins and other nutrients, but it is not recommended to feed it to them frequently.
Feeding cats large amounts of grapefruit pulp can irritate their stomachs. However, it's important to note that cats should not eat common foods such as chocolate, alcohol, or xylitol. If a cat accidentally ingests these substances, it should be taken to the vet immediately.
