Ryegrass Toxicity in Elephants

• Ryegrass staggers

• Fermented hay containing ryegrass. (P9.2004.w2)

• Ryegrass toxicity, following ingestion of fermented hay, has been reported in captive Elephas maximus - Asian Elephants. (P9.2004.w2)

Clinical signs:

• Severe ataxia, with initial improvement only after several days and return to normal taking up to 18 days. (P9.2004.w2)
• Other findings were normal (e.g. oral mucosa pink and moist, normal peristaltic sounds, normal body temperature). (P9.2004.w2)

Clinical pathology:

• A blood sample from the first affected elephant showed a blood alcohol level of 0.0024% - too low to account for the signs. (P9.2004.w2)

• One female Elephas maximus - Asian Elephant from a group was affected initially. Despite the removal of the suspect hay from the diet, a second female started to show signs four days later and the breeding male showed signs starting one day after the second female. (P9.2004.w2)

Differential diagnosis

• Initially, since the hay was fermented, alcohol toxicosis was suspected (See: Alcohol Poisoning). This diagnosis was rejected due to the low blood alcohol level and the long time for which the clinical signs persisted. (P9.2004.w2)

Treatment

• Treatment in these cases was limited to observation and protecting the affected animals from hazards (e.g. indoor housing to keep the ataxic individuals from falling into the moat around the external enclosure). (P9.2004.w2)
• If signs had progressed further, treatment with acepromazine or diazepam, as for horses with this condition, would have been considered. (P9.2004.w2)

• History & Documentation
• Physical Examination of Mammals
• Necropsy of Mammals
• Treatment and Care - General
• Environmental Assessment
• Chapter 2 - B36 Field Manual of Wildlife Diseases - Specimen Collection and Preservation
• Chapter 3 - B36 Field Manual of Wildlife Diseases - Specimen shipment
• Appendix A - B36 Field Manual of Wildlife Diseases - Sample specimen history form

• Elephas maximus - Asian Elephant

(List does not contain all other species groups affected by this disease)