Objective: To report clinical and epidemiologic information, summarize characteristic clinical signs and laboratory results, and describe the expected course of cycad toxicosis in dogs.
Design: Retrospective study.
Animals: 60 dogs with evidence of cycad ingestion.
Procedure: The National Animal Poison Control Center's case record database was searched for records of dogs ingesting cycad plants from January 1987 to November 1997. Data were retrieved on clinical signs, laboratory test results, exposure history, and physical examination findings. Cases were assessed as toxicosis, suspected toxicosis, or possible toxicosis.
Results: Records from 60 dogs were retrieved; 89.7% of the dogs were from the southern United States, 38.7% ingested seeds, 95% developed liver and gastrointestinal tract problems, and 53.3% had abnormal neurologic signs. High serum bilirubin concentration and alkaline phosphatase and alanine aminotransferase activities were the most common serum biochemical abnormalities. Although clinical signs were observed within 1 day, laboratory values did not change for 24 to 48 hours after cycad ingestion. Mortality rate was reportedly 32.1%.
Clinical implications: 68% of dogs responded well to treatment and supportive care. Dogs ingesting seeds are likely to develop more serious problems. Clinical signs can develop within 1 to 3 days and can last for several days. A tentative diagnosis should be made on the basis of history of ingestion, clinical signs, and duration of signs. Because of the nature of these toxins, cycad ingestion is serious and should be treated aggressively.