There are five main herbal poisonings that we see in pets. We will discuss each one individually.

No. 1 is ephedrine and pseudoephedrine. These are naturally found in many plants, including the sea plant, Indian common mallow, ma huang and yellow horse. These compounds are used medicinally for weight loss and decongestants. And they are used illicitly as herbal ecstasy and as precursors for methamphetamine. They are rapidly acting central nervous system stimulants. Clinical signs of ingestion include restlessness, agitation, vocalizing, muscle tremors and seizures. Death can occur. Diagnosis is based on a history of exposure and compatible clinical signs. Signs can develop quickly, so vomiting is induced only under the direction of a veterinarian. Activated charcoal may be administered. In severe cases, hospitalization is required for monitoring of heart rate and rhythm and to provide treatments if seizures are present. Prognosis is good for animals that received prompt treatment.

No. 2 is an herb called guarana. This is an herbal stimulant that contains 3-5 percent caffeine, and comes from seeds that are called Paullinia cupana. This is a caffeine source used in the soft drink industry. Initial signs include vomiting, hyperactivity and increased drinking and urination. Muscle tremors and seizures can also occur, as can death. Again, vomiting is induced. Administration of activated charcoal binds the caffeine and prevents further absorption. Hospitalization for monitoring and treatment may be necessary for animals with severe exposure. Anticonvulsants, sedatives, medications to correct heart arrhythmias and intravenous fluids may be necessary. Prognosis is good for animals receiving prompt treatment. If treatment is delayed or prolonged or severe signs occur, prognosis is poor.

No. 3 is St. John’s wort. This herb comes from a plant called hypericum perforatum, which contains hypericin, which again acts on the central nervous system. Other common names are rosin rose and Klamath weed. St. John’s wort stimulates a number of neurotransmitters in the brain. Initial signs include vomiting, diarrhea and lethargy. Vocalizing, muscle tremors and seizures can occur with large ingestions. Vomiting again is induced only under the direction of a veterinarian. Activated charcoal is beneficial if large amounts were consumed. Hospitalization and medications to control tremors or seizures may be necessary. Sometimes the liver is affected and medications for the liver are necessary.

No. 4 is echinacea. This comes from the purple cone flower and scurvy root. It is used as an immune stimulant. The most common problems with large ingestions of echinacea are vomiting and diarrhea. Most gastrointestinal signs are self-limited and prognosis is excellent.

No. 5 is valerian. The root of valerian is used as a sedative and sleeping aid. Other common names are all-heal, Vandal root and heliotrope. The sedative effects from most ingestions are short-lived and do not require treatment. Affected animals should be confined to prevent self-injury such as falling. For large ingestions, induced vomiting through your veterinarian and activated charcoal may be recommended. The prognosis is excellent for valerian ingestions.


Dr. Karsten Fostvedt is a veterinarian at St. Francis Pet Clinic in Ketchum.

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