Why Is Grapefruit Harmful for Pets?

Grapefruit contains furanocoumarins that interfere with drug metabolism enzymes, plus extreme acidity causing vomiting, diarrhea, GI ulceration, liver toxicity, and hypersensitivity reactions especially dangerous for pets on medications. Symptoms escalate to weakness, tremors, kidney strain, and photosensitivity dermatitis. Dogs, cats, and rabbits react strongly; even juice or peels toxic. Flush the system with plenty of water under vet guidance, avoid all citrus entirely, and monitor for drug interactions if your pet takes heartworm preventives or pain meds.