Weekly Disease Roundup: December 20-26, 2025

As 2025 draws to a close, equine disease activity remains elevated, particularly for EHV-1 Neurologic (EHM). This week saw 8 new disease alerts across 6 states, with neurological herpesvirus cases accounting for the majority of reports.

This Week at a Glance

MetricThis WeekLast WeekChange
Total Alerts811-27%
States Affected6--
EHV-1 Neurologic Cases5--

EHV-1 Neurologic: The Dominant Concern

Five of this week's eight alerts (62%) involved Equine Herpesvirus-1 Neurologic (EHM), the most serious form of equine herpesvirus. This neurological variant can cause devastating symptoms including:

  • Hind limb weakness or paralysis
  • Loss of bladder and tail tone
  • Incoordination (ataxia)
  • Recumbency in severe cases

States Reporting EHM This Week:

  • New Mexico (2 cases): Eddy County and Dona Ana County both reported new cases on December 24. Both facilities are under official quarantine with a combined 3 confirmed cases.
  • Florida: Palm Beach County reported a case on December 23, now under official quarantine.
  • Colorado: Larimer County confirmed a case on December 23, under official quarantine.
  • Louisiana: East Baton Rouge Parish reported 3 confirmed cases on December 22, the highest single-location count this week.

All EHM cases are currently under official quarantine, reflecting the serious nature of this disease.

Strangles Activity

Two strangles cases were reported this week:

  • Washington (Stevens County): A new case reported December 22, under voluntary quarantine.
  • Wisconsin (Waupaca County): A case reported December 20, also under voluntary quarantine.

Strangles remains one of the most common equine infectious diseases, spreading easily through direct contact and shared equipment.

Resolved Case: Good News from Washington

Washington's Spokane County reported a resolved EHV-1 (non-neurological) case on December 22. This is a positive reminder that with proper quarantine and veterinary care, horses can recover from herpesvirus infections.

Geographic Spread

This week's alerts came from coast to coast:

StateAlertsPrimary Disease
New Mexico2EHV-1 Neurologic
Washington2EHV-1, Strangles
Colorado1EHV-1 Neurologic
Florida1EHV-1 Neurologic
Louisiana1EHV-1 Neurologic
Wisconsin1Strangles

Holiday Travel Advisory

With many horses traveling for holiday events and year-end shows, we remind horse owners to:

  • Check destination states for disease activity before traveling
  • Isolate returning horses for 14-21 days when possible
  • Monitor temperatures daily - fever is often the first sign of EHV-1
  • Avoid nose-to-nose contact at events and rest stops
  • Don't share water buckets or equipment with unfamiliar horses

What to Watch Next Week

As we head into 2026, we'll be watching:

  • Whether the New Mexico EHM cases expand or remain contained
  • Post-holiday disease reports as horses return from travel
  • Continuation of the current EHV-1 activity pattern

Looking at the Bigger Picture

Despite holiday slowdowns in reporting, this week's 8 alerts represents continued disease activity. The 3-week trend shows:

  • 2 weeks ago: 5 alerts
  • Last week: 11 alerts
  • This week: 8 alerts

The elevated EHV-1 Neurologic activity we've seen in late 2025 warrants continued vigilance from horse owners nationwide.


View the interactive outbreak map or check your state's disease activity for the latest updates. Data sourced from the Equine Disease Communication Center (EDCC).