Toxicology Brief: Cycad toxicosis in dogs - Veterinary Medicine
Medicine Center
DVM Veterinary Medicine Featuring Information from:


Toxicology Brief: Cycad toxicosis in dogs



Treatment of cycad toxicosis is symptomatic and supportive. No antidote for any cycad toxin is available.2 Measure hepatic enzyme activities and bilirubin concentrations on presentation, and monitor these values daily for 72 hours. If elevations are found, monitor the parameters until they return to normal. Administer supportive therapy as needed.

Asymptomatic patients

Perform gastric lavage or induce emesis by using hydrogen peroxide (1 ml/lb; maximum = 45 ml) in asymptomatic dogs as soon as possible after suspected ingestion. Repeated doses of activated charcoal at 1 to 2 g/kg may be given after emesis.

Symptomatic patients

If clinical signs are present, supportive therapy is indicated. For gastrointestinal signs, administer sucralfate (1 g in large dogs or 0.5 g in small dogs orally every eight hours) and cimetidine (5 to 10 mg/kg intravenously or orally every eight hours if the dog is not vomiting) or other gastric acid inhibitors.12 Supportive fluid therapy with 5% dextrose in 0.9% saline solution is recommended, and blood glucose concentrations should be closely monitored.13 Seizures and tremors may be controlled with diazepam (2 to 5 mg/kg intravenously in dogs, as needed).12 If gastrointestinal tract hemorrhage is severe, blood transfusions may be necessary.

Monitor dogs for secondary effects of liver failure, such as coagulopathy, hepatic encephalopathy, hypoproteinemia, or renal failure, and treat these conditions as needed.10 A low-protein bland diet is recommended. S-adenosyl-methionine (17 to 20 mg/kg daily in dogs) has been recommended in the long-term management of hepatic injury.12


A patient's prognosis is good if treatment is instituted soon after cycad ingestion. However, if the patient is showing clinical signs, its prognosis is guarded.2 The reported mortality rate in dogs with clinical signs is 32.1%.11

"Toxicology Brief" was contributed by Hany Youssef, BVSc, DVM, MS, ASPCA Animal Poison Control Center, 1717 S. Philo Road, Suite 36, Urbana, IL 61802. The department editor is Petra Volmer, DVM, MS, DABVT, DABT.


1. North Carolina Cooperative Extension Service, North Carolina State University. Poisonous plants of North Carolina. Available at: Accessed Mar 31, 2008.

2. Albretsen J. Cycasin. In: Plumlee KH. Clinical veterinary toxicology. St. Louis, Mo: Mosby, 2004;392-394.

3. Cheeke PR. Natural toxicants in feeds, forages, and poisonous plants. Danville, Ill: Interstate Publishers, 1998;388-389.

4. Hooper PT. Cycad poisoning in Australia—etiology and pathology. In: Keeler RF, Van Kampen KR, James LF, eds. Effects of poisonous plants on livestock. New York, N.Y.: Academic Press, 1978;337-347.

5. Kinghorn D. Carcinogenic and cocarcinogenic toxins from plants. In: Keeler RF, Tu AT, eds. Handbook of natural toxins: plant and fungal toxins Vol 1. New York, N.Y.: Marcel Dekker, 1983:239-298.

6. Senior DF, Sundloff SF, Buergelt CD, et al. Cycad intoxication in the dog. J Am Anim Hosp Assoc 1985;21:103-109.

7. Botha CJ, Naude TW, Swan GE, et al. Suspected cycad (Cycas revoluta) intoxication in dogs. J S Afr Vet Assoc 1991;62(4):189-190.

8. Knight MW, Dorman DC. Selected poisonous plant concerns small animals. Vet Med 1997;92(3):260-272.

9. Reams RY, Janovitz EB, Robinson FR, et al. Cycad (Zamia puertoriquensis) toxicosis in a group of dairy heifers in Puerto Rico. J Vet Diagn Invest 1993;5(3):488-494.

10. Albretsen JC, Khan SA, Richardson JA. Cycad palm toxicosis in dogs: 60 cases (1987-1997). J Am Vet Med Assoc 1998;213(1):99-101.

11. AnTox Database. Urbana, Ill: ASPCA Animal Poison Control Center, 1988-1998.

12. Plumb DC. Veterinary drug handbook. 5th ed. Ames: Iowa State University Press, 2005;245-248, 340-345, 995-997, 1038-1039.

13. Leveille-Webster CR. Diseases of the hepatobiliary system. In: Morgan RV, ed. Handbook of small animal practice. 3rd ed. Philadelphia, Pa: WB Saunders Co, 1997;383-401.


Click here