Is Begonia Toxic to Cats?

Is begonia toxic to cats?

Begonia is toxic to cats. The toxic principle is soluble oxalic acid which is rapidly absorbed in the gastrointestinal tract and binds to systemic calcium causing blood calcium levels to drop suddenly (acute hypocalcemia) as well as the formation of insoluble calcium oxalate (CaOx) which accumulate in the renal tubules, leading to acute renal (kidney) failure.

Thankfully, begonia toxicity in cats is rare as they typically won’t ingest enough to cause clinical signs, livestock are at the greatest risk due to the large quantity of plant material they can consume. Dehydrated cats or cats with chronic renal failure may be at increased risk.

What is begonia?

  • Botanical name: Begoniaceae
  • Common names: Begonia
  • Toxicity: Toxic to cats
  • Toxic parts: All parts, especially the tubers
  • Severity: Moderate to severe if large amounts are ingested
  • Toxic properties: Oxalate salts

Begonia is a herbaceous flowering plant of 2,000 species native to moist subtropical and tropical climates of South and Central America, Southern Asia and Africa. It is popular as an indoor houseplant as well as a garden plant in warmer climates.

Clinical signs

There is no toxic dose, and symptoms will depend on the amount of oxalis ingested as well as the overall health of the cat. Cats who are dehydrated or have chronic kidney disease are at increased risk.

  • Weakness
  • Lethargy
  • Hypersalivation (drooling)
  • Gastrointestinal signs (loss of appetite, vomiting, diarrhea)
  • Tremors secondary to hypocalcemia
  • Kidney damage 24-36 hours after ingestion (altered urine output, blood in the urine, increased thirst)

What should you do if your cat has ingested begonia?

In most cases, cats will ingest an insignificant amount of begonia to cause clinical signs. If a large amount has been ingested, seek immediate veterinary care.

As always, if you are unsure of the toxicity of a plant, contact your local veterinarian or animal poisons control for further advice.


If ingestion was recent, gastric decontamination will be initiated by inducing vomiting and administering activated charcoal to bind to any remaining plant matter in the gastrointestinal tract. Additional treatments will depend on the severity of clinical signs and may include:

  • Fluid therapy
  • Antiemetic therapy
  • Clinical monitoring


The only way to prevent begonia toxicity is to not grow it in homes with pets. If you do, have begonia, make sure it is in a heavy pot that can’t be knocked over, and when re-potting or planting in garden beds, do not leave the tubers uncovered to prevent ingestion by cats or dogs.


  • Julia Wilson, 'Cat World' Founder

    Julia Wilson is the founder of Cat-World, and has researched and written over 1,000 articles about cats. She is a cat expert with over 20 years of experience writing about a wide range of cat topics, with a special interest in cat health, welfare and preventative care. Julia lives in Sydney with her family, four cats and two dogs. Full author bio