Verdict: In moderation
While plain, cooked tuna in moderation is generally safe for dogs, regular or large consumption, especially of canned tuna in oil or brine, can lead to health issues. High mercury levels in tuna are a concern for long-term health, and excessive salt or fat can cause gastrointestinal upset or pancreatitis.
Mercury bioaccumulates and is a neurotoxin; excessive sodium can lead to hypernatremia; high fat can trigger pancreatitis.
Mercury, Sodium, Fat