Lenten rose contains several toxins, including bufadienolide, glycosides, veratrin, and protoanemonin that can result in gastrointestinal symptoms and respiratory and central nervous system depression in cats. As this plant is highly toxic, if you think your cat has ingested it seek veterinary assistance immediately.

Lenton rose, commonly known as hellebore, Christmas rose or Easter rose, is toxic to cats and other animals. Its scientific name is Helleborus niger, and it belongs to the buttercup family. In warm climates the foliage is evergreen. They are a valued ornamental plant as they bloom early in spring, producing some of the first spring flowers. 

The primary symptoms of hellebore/Lenten rose poisoning are gastrointestinal and include:

Additional symptoms include:

Irritation of the skin can occur from physical contact.

Lenten rose poisoning in cats is rare as the plant is unappetizing, having a burning effect due to the toxin protoanemonin, which irritates skin and mucous membranes at the time of ingestion. This usually prevents a cat from consuming a large quantity of the plant. This toxin is found in all parts of the plant and serves to protect the plant from consumption, the toxin is released when the plant is eaten, causing immediate discomfort in the mouth and esophagus and resulting in rash and blistering of the oral cavity.

Additional toxins present in the plant including bufadienolide, glycosides, and veratrin cause further gastrointestinal, cardiac, and respiratory symptoms.

As this plant is commonly kept as an ornamental plant in gardens, your cat may have access to ingest this toxic plant. If not dissuaded by the oral discomfort, cats may ingest sufficient quantities to produce severe toxicity symptoms.

If you witness your cat ingesting or coming into contact with Lenten rose, seek veterinary assistance. If possible, bring the plant ingested for confirmation of its identity by your veterinarian. Your veterinarian will conduct a physical exam, require medical history, and may also initiate blood and urine tests to ascertain the condition of your pet. Lenten rose ingestion is associated with digitalis-like symptoms and the presence of these symptoms in conjunction with Lenten rose exposure will result in a Lenten rose toxicity diagnosis.

If ingestion is recent, vomiting will be induced or gastric lavage performed to purge stomach contents, followed by the administration of activated charcoal to absorb toxic compounds in your pet's gastrointestinal tract and minimize absorption in the gut. Gastrointestinal symptoms may be treated with antacids to coat the gastrointestinal tissues and ease pain and discomfort. Your cat's vital signs will be monitored. If cardiac symptoms appear, medication to address cardiac dysfunction such as atropine may be administered intravenously. If respiratory distress occurs, your cat will be administered oxygen therapy. Close monitoring of additional organ functions such as liver and kidney will be conducted and impairments addressed as required. 

If your cat has ingested Lenten rose, in spite of its unpalatability, remove the plant from your cat's environment so further exposure and repeat poisoning cannot occur. Your cat may need ongoing medication to address respiratory, cardiac or organ function issues if they occurred. Additionally, a specialized diet to support organs may be recommended. A bland diet designed to reduce gastrointestinal upset may be required for several days.