Wax Leaf Poisoning in Cats

Wax leaf, when consumed in small quantities, does not usually cause a serious case of poisoning. However, since owners have no way of knowing the full extent of poisoning without the help of a veterinary professional, you should take your cat to the vet if you believe it has ingested the wax leaf in any quantity.

The wax leaf is a type of shrub that is toxic to cats, dogs, and horses. The wax leaf is a member of the Oleaceae family. Plants within this family contain oleanolic acid, which is a gastrointestinal irritant in many domestic animals. The wax leaf in particular also contains terpenoid glycosides, which also affect the gastrointestinal system. You can recognize the wax leaf shrub by its unique leaves, which often have a curly or wavy appearance.

Gastrointestinal signs of wax leaf poisoning will usually appear within two hours following ingestion. If you notice any of the following symptoms, take your cat to the vet as soon as possible:

• Vomiting
• Drooling
• Loss of appetite
• Loss of coordination*
• Rapid heart rate*
• Sudden death (very rare)*

*Denotes serious symptoms associated with ingestion of larger quantities.

Types

The wax leaf is known by many different names, including:

• Privet
• Common privet
• Amur
• Ligustrum japonicum

The cause of wax leaf poisoning is ingestion of the plant. All parts of the wax leaf shrub contain toxic oleanolic acid and terpenoid glycosides, including the leaves and stems. Oleanolic acids contain important antioxidants and are found in many foods and medicinal herbs. In humans, oleanolic acids are used in certain medications to treat liver conditions. Although these substances are effective in treating inflammatory conditions in humans and laboratory animals such as rats, oleanolic acids are toxic to dogs, cats, and horses. 

Cats do not usually ingest large quantities of poisonous plants because gastrointestinal signs appear quickly. However, you should consult your vet immediately if your cat has ingested the wax leaf. Even if your cat’s symptoms appear to be mild, serious symptoms associated with ingestion of large quantities may not yet have occurred.

Call your vet before you arrive if your cat is experiencing severe symptoms. If the wax leaf is a shrub growing in your garden, take a sample of it with you when you go. Always let your vet know how long your cat has been experiencing symptoms. Tell them how much of the plant your cat ingested if you know.

For mild cases of wax leaf poisoning, presentation of symptoms and standard diagnostic tests – usually blood and urine tests – are sufficient to make the diagnosis. Other tests, such as a neurological exam or an ECG, may be recommended if your cat is experiencing serious symptoms.

Mild cases of wax leaf poisoning will be treated using standard methods of treatment for plant poisoning. These include the administration of activated charcoal, intravenous nutrition and/or fluid therapy, and anti-emetic drugs. Activated charcoal can absorb undigested oleanolic acid and terpenoid glycosides in the stomach. Intravenous nutrition and fluid therapy can help correct fluid and nutrition imbalances in cats that refuse their food and water. Anti-emetic drugs can control persistent vomiting.

If your cat has ingested large quantities of the wax leaf, your vet will recommend treatment based on symptoms. Hospitalization may be required for cats with life-threatening cardiac signs.

As long as wax leaf poisoning is diagnosed and treated quickly, recovery and prognosis for mild cases is usually good or excellent following treatment. Mild cases usually resolve within 24 hours. For severe cases of wax leaf poisoning, the prognosis may be more guarded based on the severity of symptoms.

Follow-up appointments will not usually be necessary for mild cases of wax leaf poisoning. For more severe cases, your vet may schedule follow-up appointments as needed following treatment. During these appointments, your vet may conduct an ECG to monitor heart function, or other tests based on symptoms.

Since the wax leaf is a shrub, it is very likely your cat will have come across the wax leaf during outdoor activity. It may be a good idea to monitor or reduce your cat’s outdoor activity to ensure they do not become poisoned again. If the wax leaf is a shrub in your own lawn or garden, removing it may be the best way to reduce the risk of poisoning.