Can a Chihuahua eat sardines?
Yes, fresh or canned in water.
How much: 1 small sardine once or twice a week, with no large bones or added salt.
Why
An excellent source of omega-3s, calcium and vitamin D. If they're canned, make sure they're packed in water, not in oil with salt.
Sardines 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.