Fuzzytumz logo

Can the St. John’s Wort Plant be Harmful to Cats? 

Gothic-style artistic depiction of a St. John’s Wort plant (Hypericum perforatum) with intricate detailing.

St. John’s Wort (Hypericum perforatum) is a flowering plant that can be toxic to cats if ingested. While not technically an allergy, this yellow-flowered shrub contains compounds called hypericin and hyperforin which cause photosensitization in felines, leading to severe skin reactions when exposed to sunlight.

St. John’s Wort is commonly found in temperate regions worldwide, often growing as an invasive weed in gardens and natural areas.

St. John’s Wort’s Toxicity Level

(Level 3) - Moderately Toxic

  • Level 1 - Minimally Toxic

    Ingestion may cause mild gastrointestinal upset, but is generally not life-threatening.

  • Level 2 - Mildly Toxic

    Ingestion can result in mild symptoms like vomiting, diarrhea, or drooling. Rarely fatal but may require veterinary care.

  • Level 3 - Moderately Toxic

    Eating these plants can lead to more pronounced symptoms like abdominal pain, lethargy, or difficulty breathing. Veterinary intervention may be necessary.

  • Level 4 - Highly Toxic

    Ingesting even small amounts can cause severe symptoms like organ damage, seizures, or cardiac failure without rapid treatment.

  • Level 5 - Extremely Toxic

    All parts of these plants are extremely poisonous to cats and can quickly lead to death, even with immediate veterinary care.

** Please note: Please note that toxicity level can vary based on the amount ingested and the specific cat. It's always best to keep these plants completely inaccessible to cats and seek immediate veterinary care or call the poison hotline if you suspect your cat has ingested any part of a toxic plant.

Health symptoms your cat might show

If a cat ingests any part of the St. John’s Wort plant, they may develop symptoms related to photosensitivity. Common signs include:

  • Skin rednessswelling, and blistering, especially on lightly pigmented areas
  • Itching and pain in affected areas
  • Fever
  • Lethargy
  • Loss of appetite
  • Drooling or mouth irritation
  • Diarrhea
  • Confusion or disorientation

Easily Filter Through Our Comprehensive 400+
Toxic Plants Archive Today

Potential diagnosis your Vet may give

If you suspect your cat has ingested St. John’s Wort, it’s crucial to seek veterinary care immediately. Your vet will likely perform the following diagnostic steps:

  1. Physical examination to assess skin lesions, vital signs, and overall condition
  2. Blood tests to evaluate organ function and check for signs of toxicity
  3. Urinalysis to look for abnormalities and aid in diagnosis
  4. Skin biopsy of affected areas to rule out other causes like autoimmune disease or infection

Based on the exam findings and test results, your vet may diagnose St. John’s Wort toxicosis and recommend an appropriate treatment plan.

An illustrative banner depicting an anthropomorphic cat in a vet's office, alongside a call-to-action message that reads: 'If you suspect your pet may have ingested a potentially toxic substance,' accompanied by a prominent button stating 'Find A Vet Near Me!
An illustrative banner depicting an anthropomorphic cat in a vet's office, alongside a call-to-action message that reads: 'If you suspect your pet may have ingested a potentially toxic substance,' accompanied by a prominent button stating 'Find A Vet Near Me!

Frequently Asked Questions About the St. John’s Wort Plant Toxicity for Cats

Q: Is St. John’s Wort toxic to cats?

A: Yes, St. John’s Wort is toxic to cats. It can cause symptoms like vomiting, diarrhea, and photosensitivity due to its harmful compounds, such as hypericin.

Q: What happens if a cat eats St. John’s Wort?

A: If a cat eats St. John’s Wort, it may experience symptoms like vomiting, skin irritation, and photosensitivity. Immediate veterinary care is necessary to prevent more serious complications.

Q: Are all parts of the St. John’s Wort plant toxic to cats?

A: Yes, all parts of the St. John’s Wort plant are toxic to cats, including the leaves, stems, and flowers. These parts contain toxic substances that can lead to poisoning if ingested.

Q: How much St. John’s Wort is harmful to cats?

A: Even small amounts of St. John’s Wort can be harmful to cats. Ingesting any part of the plant can cause toxic reactions, so it’s important to keep it away from your pets.

Q: Can St. John’s Wort poisoning in cats be fatal?

A: While St. John’s Wort poisoning is rarely fatal, it can cause significant health problems in cats. Prompt treatment is essential to alleviate symptoms and ensure recovery.

Q: What should I do if my cat ingests St. John’s Wort?

A: If your cat ingests St. John’s Wort, contact your veterinarian immediately. Early intervention can reduce the toxic effects and protect your cat’s health.

The Historical Journey of the St. John’s Wort Plant

St. John’s Wort has a long history of use dating back to ancient Greece. The plant’s name refers to John the Baptist, as it typically blooms around the feast day of St. John in late June. Historically, St. John’s Wort was used to treat a variety of ailments including kidney and lung issuesinsomniawound healing, and depression.

In modern times, it is still widely used as an herbal supplement for mild to moderate depression, although its effectiveness remains controversial.

Further reading and sources

Please note: The information shared in this post is for informational purposes only and should not be considered as veterinary medical advice.

Hit the kitty paws and help increase worldwide cat karma!

901