Is Sodium hydroxide (lye) safe for dogs and cats?

Dogs are exposed to sodium hydroxide primarily through licking or chewing drain cleaner products, contact with residual lye solution on recently cleaned drain surfaces, or investigation of oven cleaner spills. Dogs' inquisitive behavior (especially puppies) and tendency to lick surfaces increases oral and mucosal exposure risk. Caustic ingestion in dogs produces oropharyngeal burns, drooling, retching, anorexia, and in severe cases esophageal stricture or gastric perforation. The severity of injury depends on NaOH concentration, contact time, and volume ingested. Dilute solutions may cause self-limiting GI irritation; concentrated drain cleaners (≥10% NaOH) can cause severe esophageal burns requiring intensive veterinary management including endoscopy, sucralfate, and feeding tube placement. Prognosis for severe caustic esophageal injury in dogs is guarded, as post-burn stricture formation is common. First aid involves dilution with water or milk and immediate veterinary evaluation — do not induce emesis (re-exposure of esophagus to caustic material worsens injury).

Cats are exposed to sodium hydroxide through contact with lye-containing drain cleaners and household cleaning products, and critically through grooming — cats may walk through spilled or residual NaOH solution and ingest it during paw licking. Even brief contact with concentrated NaOH on a cat's paw pads can cause chemical burns, and the subsequent grooming behavior delivers NaOH to the oral mucosa and esophagus. Cats are fastidious groomers, meaning dermal NaOH contact almost always results in secondary oral exposure. Clinical signs include pawing at the mouth, excessive salivation, reluctance to eat, and in severe cases retching and signs of esophageal pain. Cats are at particular risk from topically applied oven cleaners used in homes where the cat has access to recently cleaned surfaces before the cleaner is fully rinsed. Treatment parallels that in dogs; given cats' smaller body size, a smaller volume of NaOH solution is needed to produce significant mucosal injury.