Every dog is different. Individual allergies and sensitivities are common — always introduce new foods in small amounts and watch for adverse reactions. This site is for informational purposes only and is not veterinary advice. Always consult your vet.
The Full Picture
Grapefruit contains psoralen compounds and essential oils that are toxic to dogs, much like lemons and limes. The peel, seeds, and pith have the highest concentrations, but even the flesh is acidic enough to cause significant gastrointestinal upset including vomiting and diarrhea. While orange flesh is safe for dogs in moderation, grapefruit is too acidic and toxic. Most dogs dislike the bitter taste, but grapefruit should be kept out of reach to prevent accidental ingestion.
What You Should Know
Grapefruit should be kept well away from dogs. If your dog has eaten grapefruit, watch for symptoms such as vomiting, diarrhea, lethargy, or loss of appetite. In an emergency, contact your veterinarian or an animal poison helpline straight away.