Begonias are a common variety of flowering plant which are often utilized in flowerbeds and larger pots due to their large, colorful flowers. However, gardeners should be aware that despite its alluring appearance, the begonia can be surprisingly toxic if eaten. Cats and other small mammals are especially vulnerable to the effects due to the relatively small amount of begonia that will need to be eaten in order to cause damage and discomfort.

Though begonia poisoning is not usually life-threatening, it can produce some fairly obvious symptoms. Owners who observe these signs should take their cat straight to a vet, lest more serious complications arise.

The begonia plant contains large amounts of a substance known as oxalate. Once ingested, the oxalate crystals embed themselves in various tissues causing irritation and can break down into 'oxalic acid', which is also a potent irritant. The cat's body will attempt to avoid further irritation and damage to the digestive tract by vomiting and attempting to dilute the acid with saliva. Eventually, a quantity of the toxin will make its way into the bloodstream, taking it to the liver. This turn of events can be especially dangerous, as in sufficient quantities oxalic acid can induce catastrophic liver failure, leading to serious illness and even death.

In order to make a complete diagnosis, the vet may need to run some tests to determine the exact nature of the substance the cat has ingested. These tests will usually include analysis of the blood and a physical examination. Notifying your vet about the cat’s potential access to the begonia plant can simplify diagnosis to speed up treatment. 

Most cases of begonia poisoning are fairly mild, clearing up by themselves in roughly forty eight hours. The vet may however recommend a prescription diet, as these are both easier on the stomach and will help dislodge any oxalate crystals still lodged in the digestive system. Anti-inflammatories will be needed in order to reduce any swelling in the throat and ensure a clear airway. Additional drugs may also be required in order to protect the stomach lining. Depending on whether or not dehydration has set in, fluid therapy may also be needed.

The total recovery time for a severe case of begonia poisoning is typically fairly short, with most being resolved within the space of two weeks at a maximum and follow up appointments not usually being necessary. The reason for this is that the oxalate crystals quickly lose their potency, meaning that without ingesting more, the levels of oxalic acid in the body will quickly fade. This is good news for cats and their owners, as it means that the amount of time that exercise and normal feeding will be restricted for will be kept to a minimum. However, if there has been notable damage to the esophagus, then the vet may opt to temporarily install a feeding tube . This will prevent the cat from stressing damaged tissues in the digestive tract by swallowing, instead subsisting on a liquid diet until they are sufficiently healed.