Why Rhubarb Leaves Are More Dangerous Than the Stalks
Rhubarb (Rheum rhabarbarum) leaves contain water‑soluble calcium oxalate crystals, which are absent in the edible stalks.
When ingested, these crystals bind dietary calcium, leading to hypocalcemia and direct tubular damage in the kidneys.
Clinical signs typically develop within hours and may include vomiting, drooling, loss of appetite, lethargy, and increased thirst or urination.
In severe cases, acute kidney injury can progress to renal failure, which is life‑threatening if not treated promptly.
Veterinary reference sources such as the Merck Veterinary Manual and ASPCA Animal Poison Control Center list rhubarb leaves as a significant hazard for companion animals.
Owners who grow rhubarb for culinary use should ensure leaves are discarded securely and kept away from pets.
Why speed matters
Delaying care significantly worsens outcomes. Some signs appear hours or days later, so "looks fine right now" is not a reason to wait.
Signs to watch for
- Excessive drooling and oral irritation
- Vomiting and diarrhea
- Loss of appetite or refusal to eat
- Lethargy, weakness, or stumbling
- Increased thirst and urination
- Tremors or seizures in severe hypocalcemia
What to do right now
- Call your veterinarian or a pet poison hotline immediately for guidance.
- Do not induce vomiting unless directed by a veterinary professional.
- If the pet is conscious and not seizuring, you may offer a small sip of water to rinse the mouth.
- Collect any plant material, vomit, or packaging to assist veterinary diagnosis.
- Transport your pet to the nearest emergency veterinary clinic without delay.
- Provide only water; do not give food, dairy, or supplements until a vet advises.
The step-by-step response, from the first minute to the vet visit, is in our Rhubarb Leaves Poisoning in Dogs and Cats emergency guide.