Why drooling signals immediate danger for a kitten
That stringy saliva means oxalate crystals are already puncturing your kitten's mouth tissues—painful microscopic injuries releasing inflammatory chemicals. At nine weeks old, her kidneys are still developing and can't filter toxins efficiently, making even one leaf potentially devastating. Unlike adult cats that might tolerate minor exposure, her tiny body lacks reserves to counteract calcium-binding effects.
The drooling also suggests she swallowed some leaf material—watch for pawing at her face or reluctance to eat, which would indicate mouth ulcers forming. Kittens dehydrate rapidly from fluid loss through excessive salivation, compounding the kidney risk. Don't rinse her mouth—this could push crystals deeper or make her aspirate water.
How kitten metabolism amplifies plant toxins
A kitten's high metabolic rate means she absorbs and distributes toxins faster than an adult cat, while her immature liver can't detoxify effectively. Rhubarb leaves contain both soluble oxalates (rapidly absorbed into blood) and insoluble ones (damaging the digestive tract)—a double threat at this life stage. Her small blood volume also means calcium levels can drop dangerously fast.
Notice whether the drool is clear or frothy—the latter suggests more severe tissue irritation. If she's vocalizing differently or avoiding touch near her cheeks, the pain may extend down her throat. These subtle signs matter because kittens often collapse suddenly without the gradual decline seen in larger pets.
The critical window for kitten poisoning cases
For neonates, the first 90 minutes post-ingestion determine treatment success—after that, oxalates begin crystallizing in the kidneys. Your vet will likely administer IV calcium gluconate to counteract what's been bound, plus pain relief for the mouth burns. They'll use pediatric fluid rates to avoid overwhelming her tiny veins while flushing her system.
Ask about warming pads during treatment—kittens can't regulate body temperature well when shocked or in pain. The team may take multiple small blood samples rather than standard volumes to monitor her electrolytes without risking anemia. Every detail is adjusted for her fragile size.
Long-term considerations after rhubarb exposure
Even if she recovers well initially, request a kidney ultrasound in 2-3 weeks—oxalate crystals sometimes leave microscopic scars that affect function long-term. Switch to wet food temporarily if mouth ulcers make chewing difficult, and monitor her litter box for straining or decreased output that might suggest lingering kidney irritation.
This incident underscores kitten-proofing needs—rhubarb leaves often fall where small pets can reach them during garden harvesting. Consider growing cat grass indoors as a safe alternative when she's teething and eager to chew on greenery. Her curiosity won't diminish, but you can control what's within paw's reach.
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.