Zamia staggers is a toxicosis condition in horses, caused by ingestion of plants of the order Cycadacae and Cycads, Macrozamia, and Zamia genera, including the well known Sago Palm plant. These plants are naturally found in tropical and subtropical regions worldwide. In the United States, they are frequently found growing in the southern states and Hawaii. Cycadacae plants are often also sold as an indoor ornamental or landscaping plant, increasing the risk of exposure to horses if found around the barn away, or anywhere that horses may gain access to.
All parts of cycadacae plants are toxic to horses, and reported to contain varying levels of three primary toxins, which include: the neurotoxin beta-methylamino-L-alanine (BMAA), the hepatoxin azoglucosides (eg, cycasin) and an unknown high molecular weight agent. Horses find the young fronds and seeds palatable and tend to seek them out if made accessible to them.
Clinical signs of toxicosis occurs within 15 minutes to several hours following ingestion of plants. The three main body systems affected in horses include the liver, central nervous system (CNS), and gastrointestinal tract.