How many dogs are going to accidently eat a rhubarb leaf? Or intentionally for that matter! Oh well, we will cover it because the Animal Poison Control says that we should!

The toxin in rhubarb is oxalate that is linked to kidney disease and death in livestock that had grazed on oxalate-containing plants such as greasewood and rhubarb leaves. During WWI, soldiers were given rhubarb leaves as a replacement for green vegetables when they were unavailable and I guess there was not only a ton of sick soldiers but even a few deaths.

Oxalate poisoning is more similar to heavy metal poisoning then your typical Agatha Christie method of using cyanide or strychnine. Oxalic acid is common in our foods and normally excreted through our urine but a build up of the crystals can lead to bladder stones. Oxalate combines with other minerals to become, for example, calcium oxalate which is a major component of kidney stones.

The lethal dose of oxalate in rats is 375mg/kg of body weight. As rhubarb leaves are about 0.5% oxalate, a human (or dog) weight 140 pounds would have to eat in the neighborhood of 11 lbs of leaves. Lethal dose then in a 35 lb dog is 2.75 lbs of rhubarb leaves – not likely a problem. However, an eighth of that number, roughly .35 of a pound or 6 ounces of rhubarb leaves would make a 35 lb dog ill.

Symptoms include overall weakness, abdominal pain, nausea, vomiting, diarrhea, burning sensations in the mouth, eyes, ears, nose and throat, difficulty breathing, convulsions, coma and death from cardiovascular collapse. Nasty!

Treatment includes the usual – take the dog to the vet so they can induce vomiting. The vet should administer activated charcoal to absorb the toxins and IV fluids will be put on board to control dehydration from the vomiting and diarrhea. Medication will be administered to control seizures and support the effected systems.

Likelihood of your dog eating rhubarb leaves is pretty slim but be safe – if you have rhubarb in your yard, fence off the area throughout the growth season.