Coconut is not toxic to cats but offered regularly is unhealthy. Coconut flesh has a high plant-based fat content and can cause diarrhea, as does coconut milk and coconut oil, and often given to your cat can lead to weight gain, fatty liver disease, and pancreatitis. Coconut water on the other hand, although it’s not high in fat, contains too much potassium for your cat and can cause hyperkalemia, a toxic excess of potassium that acidifies your cat’s blood and can cause heart damage. You should not give coconut products to cats with sensitive stomachs, diabetes, or other health conditions like liver or kidney diseases. ASPCA recommends not to let pets drink any coconut water.