Bureau of Land Management
Number Confirmed: 119;
Facility Type: Public Venue;
Breed: Mustang; Clinical Signs: A respiratory condition characterized by mild/moderate fever, coughing or nasal discharge, depression, labored breathing; Horse Status: 119 Deceased;
Notes: Update May 2, 2022 Situation Report Summary: On April 23, 2022 9 horses were found dead in 4 pens containing horses gathered from the West Douglas Herd Area in July/August of 2021. Several horses were gravely ill showing signs initially thought to be neurologic but later attributed to hypoxia from severe pneumonia. Over the next 3 days about two dozen horses died or were euthanized for severe debilitating respiratory distress in the West Douglas group of horses. Post mortem examinations consistently found pneumonia characterized by severe pulmonary edema and hemorrhage. Morbidity characterized by respiratory signs including fever, nasal discharge and coughing were also noted in 40-60% of the West Douglas horses with growing morbidity to about 20% noted in other pens throughout the facility. Over the course of the next 5 days PCR testing of blood, swabs and tissues for EHV-1 and -4 were consistently negative, however several nasal swabs and lung tissue specimens tested positive for equine influenza, confirmed to be H3N8 by PCR testing. Contributing factors include a history of gather and removal of West Douglas horses after a severe wildfire in their herd area, severe winds and dust storms in the area in the days before the outbreak. The West Douglas horses had been in the facility for about 9 months but are still unsettled, flighty as a group and easily disturbed in the pens. Most of the facility population is current (within 6 months) for flu/rhino vaccination, however the West Douglas horses in pens 40-43 are either unvaccinated, have only received one shot, or only recently received their booster shots about 10 days before the outbreak. Further testing of the samples positive for the equine influenza virus has determined the virus to be the Florida Clade 1 sublineage. This is currently the endemic strains of equine influenza in North America; For more information go to BLM situation report.
Updates on current disease outbreaks are listed on our EDCC website as they occur and will include the date listed, disease name, location and current status. Specific premises will not be named but the general location by town, county and state will be listed. When locations, events or horses are at risk they will be listed. Updates will be posted as they are received. All information is sourced from: http://equinediseasecc.org/alerts/outbreaks