Campus Alert Archive
CSU

Two Confirmed EHV-1 Cases Trigger Voluntary Quarantine at the James L. Voss Veterinary Teaching Hospital

COpublic healthadvisorymedium confidence
Confirmed Threat

On October 30, 2006, Colorado State University's James L. Voss Veterinary Teaching Hospital confirmed that two hospitalized horses had tested positive for equine herpesvirus-1 (EHV-1) -- a contagious neurological disease transmissible by contact and aerosol. The hospital voluntarily suspended all elective equine admissions effective October 31 and quarantined all 19 horses currently hospitalized, while veterinarians contacted every owner of a horse that may have been exposed at the facility. Interim hospital director Dr. Martin Fettman stated the hospital expected to resume routine operations within two weeks.

Alerts
3
Response
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Killed
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Injured
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Institution
Colorado State University
Public R1 · CO
~33,000 studentsCSU Emergency Notification
Confirmed Timeline

Alert Sequence

3 messages in sequence

Some alert texts below are approximate reconstructions from news coverage, not confirmed verbatim transcripts. Reconstructed texts are shown in italic with a dashed border. Verified verbatim texts have a solid border and are marked accordingly.

INITIAL ALERTEmail
Approximate reconstruction641 chars
Colorado State University Veterinary Teaching Hospital Notice: As of this evening, October 30, we have confirmed equine herpesvirus-1 (EHV-1) in two horses currently hospitalized at the James L. Voss Veterinary Teaching Hospital. Effective October 31, we are implementing a precautionary voluntary suspension of all elective equine admissions. All 19 horses currently hospitalized have been placed in quarantine as a precautionary measure. Veterinarians are contacting all owners of horses that may have been exposed at our facility. EHV-1 cannot be transmitted to humans. We anticipate resuming routine hospital activities within two weeks.

This text has been reconstructed from news coverage and may not reflect the exact original wording.

The Horse magazine reported that elective equine admissions were suspended 'effective October 31' -- the day after EHV-1 was confirmed in two horses on October 30, 2006, indicating a rapid institutional response
The hospital's decision to quarantine all 19 hospitalized horses -- not just those testing positive -- reflects the aerosol-transmissibility of EHV-1, which can spread through shared air space in a hospital setting
UPDATEEmail
Approximate reconstruction460 chars
CSU Veterinary Teaching Hospital Update on EHV-1 Quarantine: The James L. Voss Veterinary Teaching Hospital continues to quarantine all equine patients as we monitor for further cases of equine herpesvirus-1. We have been in contact with all owners of potentially exposed horses. Emergency equine cases continue to be accepted. We will provide updates as the situation develops and as we work with the Colorado State Veterinarian toward lifting the quarantine.

This text has been reconstructed from news coverage and may not reflect the exact original wording.

The voluntary suspension of elective equine admissions did not apply to emergency cases, allowing the hospital to continue providing critical care while controlling the spread of EHV-1 among elective cases
Coordination with the Colorado State Veterinarian was a key feature of the quarantine management, reflecting the one-health intersection between veterinary hospital operations and state animal health surveillance
ALL CLEAREmail
Approximate reconstruction463 chars
CSU Veterinary Teaching Hospital EHV-1 Quarantine Lifted: In consultation with the Colorado State Veterinarian, the James L. Voss Veterinary Teaching Hospital has lifted the equine quarantine. Serial PCR testing of all quarantined horses confirmed no further spread of equine herpesvirus-1. The hospital is resuming elective equine admissions effective immediately. We thank our clients and referring veterinarians for their patience during this difficult period.

This text has been reconstructed from news coverage and may not reflect the exact original wording.

The quarantine was abbreviated from a potential longer duration by serial PCR testing of all 19 quarantined horses -- a diagnostic protocol that allowed veterinarians to confirm no further spread and safely lift restrictions earlier than a blanket 21-day animal disease quarantine might require
The resolution in consultation with the Colorado State Veterinarian reflects the regulatory framework for animal disease management in Colorado, where state officials hold authority over quarantine decisions for reportable equine diseases
Context

Background

The James L. Voss Veterinary Teaching Hospital at Colorado State University in Fort Collins is one of the premier veterinary teaching facilities in the United States, treating horses, cattle, and other large animals from across the Rocky Mountain region. On October 23, 2006, a partially paralyzed horse was admitted on suspicion of equine herpesvirus-1 myeloencephalopathy (EHM) -- the neurological form of EHV-1 infection. Stringent biosecurity precautions were implemented around this index case, but on October 30, EHV-1 was confirmed in two additional horses that had not initially presented with the disease, indicating nosocomial (hospital-acquired) spread. The horse was isolated immediately and all elective equine admissions were suspended effective October 31, with all 19 hospitalized horses placed in voluntary quarantine. According to interim hospital director Dr. Martin Fettman, the virus -- which spreads by contact and aerosol -- cannot be transmitted to humans but poses serious risks to horses, including potentially fatal paralysis. Despite the rigorous biosecurity in place at the time of the index case's admission, a published analysis of the outbreak confirmed that EHV-1 infections spread to six additional horses before the quarantine controlled transmission. The voluntary quarantine was lifted after approximately 14 days, in consultation with the Colorado State Veterinarian, after serial PCR testing confirmed no further spread. The incident was later published as a landmark case study in the Journal of Veterinary Internal Medicine, informing EHV-1 biosecurity protocols at veterinary teaching hospitals nationwide.
Analysis

Key Findings

EHV-1 spread to six additional horses in the hospital despite biosecurity precautions implemented around the index case -- the index case was admitted October 23, and spread was confirmed on October 30, a 7-day window
The voluntary quarantine of all 19 hospitalized horses was a precautionary measure beyond the two confirmed cases, reflecting the aerosol transmission route of EHV-1
Emergency equine cases were still accepted during the suspension of elective admissions, maintaining the hospital's role as a regional emergency referral center
Serial PCR testing of quarantined horses allowed the quarantine to be lifted in approximately 14 days rather than a longer blanket quarantine period
The 2006 CSU EHV-1 outbreak was published in the Journal of Veterinary Internal Medicine and became a foundational case study for EHV-1 biosecurity management in veterinary teaching hospitals
Outcome
The voluntary quarantine of all 19 hospitalized horses was initiated on the evening of October 30, 2006. Elective equine admissions were suspended effective October 31. Veterinarians contacted all owners of potentially exposed horses. The quarantine was lifted after 14-16 days, in consultation with the Colorado State Veterinarian.
Provenance

Sources

  1. News
    Colorado State Veterinary Teaching Hospital Implements Precautionary Suspension of Elective Equine Admissions -- The Horse
    thehorse.com
  2. Report
    Detection and management of an outbreak of equine herpesvirus type 1 infection and associated neurological disease in a veterinary teaching hospital -- Journal of Veterinary Internal Medicine
    pubmed.ncbi.nlm.nih.gov
  3. Official
    CSU veterinarians monitoring for EHV-1: What horse owners need to know -- Colorado State University
    cvmbs.source.colostate.edu
Tags
equine-herpesvirusEHV-1veterinary-teaching-hospitalquarantinezoonotic-diseaselarge-animalcoloradobiosecurityanimal-diseaseone-health2006
Added June 2026Updated June 2026Via ingestion