Can a Chihuahua eat coconut?
Yes, in a very small amount.
How much: 1-2 small pieces of fresh or dried unsweetened coconut meat.
Why
Coconut provides healthy fats and lauric acid. Too much causes diarrhea because of the fat. Avoid coconut water in any quantity: it is high in potassium and sugar for a dog this small.
Coconut in a Chihuahua's diet
Keep in mind how tiny the portions are for this breed: an adult Chihuahua eats roughly 1 to 2.3 ounces (25-65 g) of food a day depending on his weight, and treats shouldn't go over 10% of his daily calories. That's only a small fraction of an ounce. What looks like "a little bite" to us can be half a meal for him.
This information is for general guidance and is not a substitute for advice from a licensed veterinarian. Every Chihuahua can react differently; if in doubt, always check with a professional.