Why is it safe?
Mild unscented dish soaps have very low toxicity. They are occasionally used by veterinarians to remove oil contamination from animal fur in emergencies. Ingesting a small lick causes mild GI irritation at most. Soaps with added antibacterial agents, fragrances, or essential oils carry higher risk.
Affected Systems
Digestive · Skin
Symptoms
Small ingestion: vomiting, diarrhea, excessive drooling. Skin contact without rinsing: irritation. Large ingestion or specialty formula: more pronounced GI symptoms.
What To Do
Rinse mouth with water. Monitor for vomiting and diarrhea. If symptoms persist beyond 24 hours or are severe: vet visit.
Notes
"Natural" or "eco" dish soaps with essential oil additions, tea tree, eucalyptus, pine, can be significantly more dangerous than conventional soap for cats. Tea tree oil in particular is highly toxic. Do not assume "natural" means safer.
Sources
→ ASPCA Animal Poison Control Center — aspca.org
→ Pet Poison Helpline — petpoisonhelpline.com