Source:  USDA/APHIS report

 

Equine Herpes Virus (EHV-1) Situation Report

May 19, 2011 

 

Background

Equine Herpes Virus (EHV-1) infection in horses can cause respiratory disease, abortion in mares, neonatal foal death, and/or neurologic disease. The neurologic form of EHV-1 is called Equine Herpes Virus Myeloencephalopathy (EHM). While EHV-1 and EHM are only officially listed as reportable diseases in some states, private veterinary practitioners are encouraged to notify their State Animal Health Officials of any suspected or confirmed cases, regardless of current official state reporting requirements.

Cases of EHV-1 and EHM have been identified recently in horses that attended the National Cutting Horse Association (NCHA) Western National Championship event in Ogden, Utah held from April 29 to May 8, 2011. The NCHA has notified State Animal Health Officials of horses from their states that were entered in the event and may have been exposed to the virus. State Animal Health Officials have contacted the owners of potentially exposed horses. Standardized recommendations were developed by state and federal officials and are being followed to isolate exposed horses, monitor them for clinical signs of EHV-1, and work with private veterinary practitioners to test and treat horses affected with the disease. Biosecurity procedures have been recommended for premises with suspect and confirmed cases to mitigate further disease spread.

Definitions for This Report

Exposed Horses: Horses that attended the Ogden, Utah event from April 29 to May 8 and horses that subsequently came into contact with horses that attended the Ogden, Utah event (secondarily exposed).

Exposed Premises: Premises with exposed horses.

Suspect EHV-1 case: A horse exposed to EHV-1 that develops fever (rectal temperature above

101.5 degrees F), but has no neurologic signs at this time.

Confirmed EHV-1 case: A suspect EHV-1 case with laboratory confirmation of EHV-1 infection, but has no neurologic signs at this time.

Suspect EHM case: A horse exposed to EHV-1 that develops neurologic signs. (Posterior incoordination, weakness, recumbency with inability to rise, and/or bladder atony are most commonly seen in EHM cases.)

Confirmed EHM case: A suspect EHM case with laboratory confirmation of EHV-1 infection.

 

Summary Information on Current Situation

•Owners of horses known to have been exposed in this incident have been contacted by State Animal Health Officials.

•Suspect and confirmed cases are reported to be under voluntary or state quarantine.

•Known exposed horses are reported to be under either voluntary or state quarantine.

•A total of 33 confirmed EHV-1 or EHM cases have been reported in 8 states (CA, CO,

ID, NM, OR, TX, UT, WA)

•Of the 33 confirmed EHV/EHM cases, 32 cases are horses that were at the Ogden, Utah

event.

•There are 7 horses associated with this incident that are dead or have been euthanized.

Current Information by Affected State

States not included in the tables below have reported there are no known exposed horses related to this incident currently within their state.

 

Table 1. Horse Information

 

STATE       Col#1   Col#2    Col#3     Col#4     Col#5    Col#6     Col#7

Arizona------   21 ------27 ------0 ----------0     ------0 --------0 --------1

California   ----54 -------* -------0 ----------5 ---------0 --------5 --------1

Colorado   ----30 ------68 -----19 ----------7 ---------0 --------2 --------2

Idaho   ---------36 -----14 ------13 ---------0 ---------3 --------1 --------2

Illinois     --------1 ------9 --------0 ---------0 ---------0 --------0 --------0

Iowa     ----------5 -----53 -------0---------- 0--------- 0 -------0 --------0

Minnesota  -----19 -----* --------0---------- 0--------- 0------- 0-------- 0

Montana   -------17----- 1-------- 1--------- 0--------- 0-------- 0------- 0

Nebraska     ---- 7------ *-------- 0--------  0----------0-------- 0------- 0

Nevada      ----- 7------- 8------- 3----------0--------- 0---------0------- 0

NewMexico  ----9------- *-------- 3--------- 1--------- 1--------- 1------ 1

Oklahoma      ----1------ 32------ 0---------- 0--------- 1---------0--------0

Oregon   --------20-----120------- 0--------- 2---------- 0-------- 0------ 0

SouthDakota   ---4-------*- -------0---------- 0--------- 0---------0------ 0

Texas  ---------  26---- 323------- *---------- *---------- 1---------1------0

Utah    ------------* -------* --------1----------5-----------2--------   -------0

Washington-----34-------0-------- 0--------- 1---------- 4-------- 2------ -0

Wyoming -------17-------34------- 1--------- 0---------- 0 ---------0------ 0

 

TOTAL---------308 ------689------41---------21---------12--------12-------7

 

COLUMN #1 = # OF HORSE EXPOSED IN OGDEN, UT

COLUMN #2 = # OF HORSES SECONDARILY EXPOSED

COLUMN #3 = # EHV-1 SUSPECT CASES

COLUMN #4 = # EHV-1 CONFIRMED CASES

COLUMN #5 = # EHM SUSPECT CASES

COLUMN #6  = # EHM CONFIRMED CASES

COLUMN #7 = # DEAD OR EUTHANIZED

 

*Information not reported

 

Table 2. Premises Information

 

STATE----------------- # Exposed-------------# Exposed premises with------- # Exposed premises

--------------------------Premises--------------- suspect or confirmed----------- with no suspect or

----------------------------------------------------EHV/EHM cases------------------ confirmed cases

 

Arizona---------------------- 11 -------------------------1--------------------------------- 10

California--------------------  *-------------------------- 6 ---------------------------------- *

Colorado------------------- 10-------------------------- 6 ---------------------------------- 4

Idaho----------------------- 23-------------------------- 6 ----------------------------------17

Illinois-----------------------  1-------------------------- 0 ----------------------------------- 1

Iowa-------------------------  2-------------------------- 0 ----------------------------------- 2

Minnesota ------------------ 7-------------------------- 0 ----------------------------------- 7

Montana---------------------  *-------------------------- 1 ----------------------------------- *

Nebraska -------------------- 3------------------------- 0 ----------------------------------- 3

Nevada----------------------  7------------------------- 2-----------------------------------  5

New Mexico----------------  6 ------------------------- 2-----------------------------------  *

Oklahoma  ------------------  1 ------------------------ 1 ----------------------------------- 0

Oregon ----------------------16 ------------------------ 2 ----------------------------------14

South Dakota --------------- 2 ------------------------ 0 ----------------------------------  2

Texas----------------------- 16 ------------------------ 2------------------------------------  14

Utah ------------------------- * ------------------------- 3------------------------------------   *

Washington--------------- 26-------------------------  7 ------------------------------------ 19

Wyoming------------------ 43 ------------------------- 1 ----------------------------------- 42

 

TOTAL ------------------   174-----------------------  40 ---------------------------------- 140

 

* Information not reported