Is Sago palm (cycasin) safe for dogs and cats?

Cycas revoluta (sago palm) and related cycad species are among the most hepatotoxic plants known to veterinary medicine. All parts of the plant are toxic, but the seeds (nuts) contain the highest concentration of cycasin and other toxins and are the most commonly ingested by dogs. Cycasin is a glycoside that is hydrolyzed by gut bacteria to methylazoxymethanol (MAM), a highly reactive methylating agent that alkylates hepatocyte DNA → acute massive hepatic necrosis. Additional toxins (beta-methylamino-L-alanine [BMAA], an excitotoxic amino acid) contribute to neurological signs. Minimum lethal dose: a single seed can be lethal to a dog. Clinical syndrome: vomiting and diarrhea within hours of ingestion; 24–48 hours later, hepatic failure (icterus, coagulopathy, hepatic encephalopathy, hypoglycemia, ascites). Mortality rate is extremely high even with aggressive supportive care: published veterinary reports indicate >50% fatality, with some series reporting 75–95% mortality despite treatment. Treatment: early emesis, activated charcoal, aggressive IV supportive care for fulminant hepatic failure (glucose, plasma, vitamin K, hepatoprotectants). Liver transplantation is not available for dogs. Sago palms are extensively planted as ornamental landscaping throughout Florida, Hawaii, and Southern California — regions with high dog exposure risk. ASPCA APCC designates sago palm as one of the most dangerous plants for dogs in the US.

Cats are susceptible to cycad toxicosis through the same mechanisms as dogs — cycasin → MAM → hepatic necrosis — but are less commonly reported in the veterinary literature for cycad poisoning, likely due to dietary selectivity (cats are less inclined to chew on plant material). When exposure does occur (particularly with plant seeds accessible to indoor cats), toxicosis is equally severe. Clinical signs, treatment approach, and prognosis are similar to dogs. Any suspected cycad ingestion by a cat is a veterinary emergency warranting immediate emesis induction (if recent) and monitoring for hepatic failure development over 48–72 hours. BMAA-related neurological signs (tremors, weakness, ataxia) may also manifest in cats.