Is Stinging Nettle toxic to cats?

Fine hairs called trichomes break upon contact, injecting histamine and other irritants into the skin or oral tissues, causing localized inflammation or systemic toxicity if ingested.

No nettle-specific treatment for cats has been published. If hives occur, vets usually treat them with an antihistamine and a steroid; in cats they use prednisolone rather than prednisone and avoid diphenhydramine. A severe allergic reaction (anaphylaxis) is treated as an emergency with epinephrine (adrenaline), fluids and other supportive care.

There is no cat-specific data. For animals in general, nettle irritation usually lasts a few minutes to a few hours and clears on its own. Hives in cats, from any cause, often fade within a few hours. They rarely kill; when they do, airway swelling or anaphylaxis is usually the cause.

• Stinging nettle (Urtica dioica), also called tall or wild nettle, grows on damp ground: stream and river banks, flood plains, ditches, meadows, woodland clearings and disturbed ground. It often forms thick patches.
• Woodland, fields and undergrowth on walks, runs and hunts. Short-coated dogs and hunting dogs that push through cover meet it most often.
• Gardens and yards, where it spreads and can form dense patches.
• The stinging hairs on its leaves and stems. Their brittle tips snap off when touched and inject an irritating fluid, so just brushing past can sting the skin, nose or face. Chewing the plant pushes the hairs into the mouth.

• Learn to recognise it: a tall, upright plant with square stems and pairs of egg-shaped, saw-toothed leaves covered in fine stinging hairs. It often grows in thick patches.
• Keep your dog on the path or on a lead in damp woodland, marshy ground, stream banks and ditches where nettles grow thickly. Take extra care with short-coated and hunting dogs that run through undergrowth.
• Keep pets away from nettle in your own garden. It spreads through underground stems and seed and can form dense patches.
• After a reaction, avoid that patch, because reactions can come back with repeated contact. Many animals learn to avoid nettles once stung, but don't count on it: one dog in a case report reacted three times in three weeks.