Shamrock

Symptoms reported in cats

Most serious first.

1. 1
   Hypocalcemic tetany (lethargy, weakness, ataxia, tremors, seizures) This occurs following a large ingestion. The soluble oxalates absorb from the gastrointestinal tract into the bloodstream, where they bind to the body's calcium.
2. 2
   Acute renal failure (polyuria/polydipsia, bloody urine) While rarely seen, this occurs if the calcium oxalates precipitate (form crystals) within the kidneys, causing direct damage to the renal tubules.
3. 3
   Gastrointestinal distress (drooling, vomiting, diarrhea, inappetence) This is the most common presentation when a cat only takes a small taste or nibble of the plant. More serious signs are not expected unless larger quantities are consumed.

Important notes

Shamrock (Oxalis species), also known as wood sorrel, is a common houseplant often mistaken for clover. While festive, it is toxic to cats because it contains soluble oxalate salts. These are different from the irritating crystals found in many other toxic plants. Unlike insoluble oxalates that cause immediate mouth pain, soluble oxalates are absorbed from the stomach into the bloodstream. Once in the blood, they bind with calcium, causing a sudden and dangerous drop in the body's available calcium. This condition, called hypocalcemia, can affect muscle function and overall stability. In cases of very large ingestions, these compounds can also form crystals in the kidneys, potentially leading to kidney damage. A cat that nibbles a small amount may only experience mild stomach upset, like vomiting or a temporary loss of appetite. However, eating a large quantity can lead to more serious signs like weakness, lethargy, and tremors. Keep shamrock plants away from cats, especially those that like to graze on greens. If a large amount is eaten, contact a veterinarian.

• Toxic compounds: soluble oxalate salts throughout the plant — leaves, stems, and bulbs
• Mechanism: soluble oxalates bind free calcium in the blood (hypocalcaemia); chronic exposure causes kidney calcium oxalate crystal deposition
• Symptoms: drooling, vomiting, diarrhea; large ingestion may cause tremors (from hypocalcaemia) or kidney issues
• The small clover-like leaves are appealing to nibbling cats — keep out of reach
• Occasional mild nibbling is usually self-limiting; contact your vet if large amounts were eaten