Cycas Revoluta: The Sago Palm, or Cycad Poisoning

Filed Under: Dogs, Cats, Poisoning

Do you have a beautiful, full, dark green exotic palm tree as a houseplant? Do you have exotic palms as part of your landscaping? If you have pets or livestock that can access these plants you may want to rethink the use of them in your garden.

The Cycas revoluta, a sago palm or sago cycad is an attractive addition to a landscape in many subtropical regions. In recent years, the sago palm has become a popular addition to gardens in the southern portions of the United States. This deep green ornamental is also often grown inside as a houseplant in areas with colder climates. Originally a native of southern Japan, this plant is drought tolerant and will grow well in shaded areas or in full sun. Since the plant is slow-growing it is also a popular bonsai plant.

The plant itself is very symmetrical, supporting a crown of shiny, dark green leaves that attach to a shaggy trunk. The plant is deciduous with male plants bearing cones and female plants bearing groups of megasporophylls.

As beautiful and as versatile as the sago palm is, it is extremely poisonous to both humans and animals when ingested. Pets, in particular, may find this species of plant very palatable. The primary toxin is cycasin, but the plant also contains Beta-methylamino L-alanine (a neurotoxin). All parts of the plant are toxic with the highest level of the toxin cycasin found in the seeds and young leaves.

Clinical symptoms of ingestion will develop within 12 hours and may include vomiting, diarrhea, weakness, seizures, liver failure, or hepatopoisoning characterized by icterus, cirrhosis, and ascites. The pet may appear bruised, have nose bleeds (epistaxis), melena (blood in the stool), hematochezia (bloody straining), and hemarthrosis (blood in the joints). The ingestion may even result in the death of the affected dog or cat.

The coagulopathy (bleeding disorder) is characterized by a thrombocytopenia (lack of thrombocytes involved in blood clotting), prolongation of the prothrombin time and activated clotting time, and activated PTT. Serum chemistries may indicate elevated liver enzymes and hypoproteinemia (low protein levels). Low serum electrolyte levels of calcium (hypocalcemia), potassium (hypokalemia), and sodium (hyponatremia) are typically encountered.

Examination of the urine will often indicate glucosuria (glucose in the urine), bilirubinuria (bilirubin in the urine), and hematuria (blood in the urine), with crystals in the urine sediment.

According to the Animal Poison Control Center in Urban, Illinois, 50% to 75% of poisoning cases involving the ingestion of sago palms resulted in fatalities.

The prognosis is poor even with treatment. When ingestion is believed to have occurred, vomiting should be induced immediately, followed by the administration of activated charcoal and a cathartic (medication to evacuate the bowls).

Cattle and sheep are susceptible to poisoning from cycads. All cycads are highly toxic. In cattle the poisoning is characterized by hindlimb paralysis, commonly known in Australia as the “zamia staggers.” In Australia Cycas macrocarpa is primarily responsible for the poisoning.

Sheep poisoned by cycads exhibit one of two distinct syndromes: with the gastrointestinal form diarrhea, hematochezia, and melena are accompanied by liver damage exhibited by icterus, cirrhosis, and ascites. The second form is neurologic and is seen as paralysis of the hind limbs with death occurring as a result of starvation. Ruminants on necropsy will have necrosis (nerve cell death) in the spinal cord.

References:

Gfeller, Roger and Shawn Messonnier. Small Animal Toxicology and Poisonings. Mosby. 1998. Pp 305-306.

Kahn, Cynthia, Ed. The Merck Veterinary Manual. 9th Ed. Merck and Co. 2005. Pp. 2480-2481.

Poisonous Palms. “Pet Age”. October 2008. P. 62.

http://.plantnet.rbgsyd.nsw.gov.au/PlantNet/cycad/toxic.html

http://.wikipedia.org/wiki/Cycas_revoluta

Topics: plants, poisonous plants, sago palm

Symptoms: bruises, diarrhea, liver failure, nosebleeds, seizures, vomiting, weakness

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