Why drooling starts so fast in a 6 kg dog
Drooling within 20 minutes means calcium oxalate crystals are piercing your dog's oral membranes. Unlike cats, dogs often drool visibly as their larger salivary glands react. A 6 kg dog has roughly half the blood calcium reserves of a 12 kg dog, making them more vulnerable to oxalate binding.
Check the lips and tongue for red streaks or swelling—these are physical crystal wounds. Offer ice water to rinse the mouth, but don't force drinking. The leaf's raw state is high-risk—cooking doesn't neutralize oxalates, but raw leaves release them faster.
Critical next steps while waiting for vet instructions
Photograph any remaining leaf fragments—their size helps the vet estimate toxin load. Note if the leaf was mature (darker green, thicker veins) or young (red-tinged, tender)—young leaves pack more oxalates per gram. Confine your dog to an easy-to-clean area; vomiting often follows drooling.
Wipe the gums gently with a wet cloth—you might feel gritty crystals. Don't induce vomiting unless directed; throat irritation from oxalates makes aspiration pneumonia a real risk. Gather your dog's medical history—pre-existing kidney issues change the treatment plan.
What to expect in the first 6 hours
The drooling phase typically lasts 1-3 hours before escalating to retching or pawing at the face. Small dogs may develop head tremors as calcium levels drop. Your vet might recommend calcium gluconate injections—oral supplements act too slowly for acute poisoning.
Monitor respiratory rate—normal is under 30 breaths/minute. Rapid shallow breathing suggests pain or metabolic acidosis. If the leaf was swallowed whole, X-rays may track its passage—oxalate crystals are radiopaque and can show up on imaging.
Longer-term risks even after one leaf
Single exposures can cause lasting kidney changes in small dogs. Ask your vet about a renal diet for the next month—lower protein reduces kidney workload. Avoid high-oxalate treats like spinach or beet greens during recovery.
Watch for increased nighttime water intake—it's often the first chronic kidney disease sign. Consider installing a pet fountain—the sound encourages drinking. For future prevention, fence off rhubarb plants—dogs often eat fallen leaves during autumn cleanup.
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.