June 2002

Vaccine Suspected In EEE Case In California

A yearling’s death was found to be likely due to the vaccine itself.

In April 2000, a Ventura County, Calif., yearling was found down, unresponsive, with abnormal eye movements and flailing leg motions. He was taken to a veterinary clinic but euthanized 24 hours later when he remained comatose.

The horse had been castrated 90 days earlier with no complications and hadn’t been ill otherwise. He was immunized seven days earlier with a combination WEE/EEE/flu and tetanus vaccine.

Tests for western equine encephalitis (WEE), Venezuelan equine encephalitis (VEE), rabies, herpes virus and West Nile virus were negative. Postmortem studies confirmed eastern equine encephalitis virus. Blood confirmed high antibody titers against EEE. No other animals on the premises were ill. …