United States Department of Agriculture • Animal and Plant Health Inspection Service • Safeguarding American Agriculture 

Veterinary Services 

Centers for Epidemiology and Animal Health November 2006 

_________________________________________________________________________________________________________________________ 

Highlights of Equine 2005 Part I: 

Baseline Reference of Equine 

Health and Management, 2005 

In 2005, the National Animal Health Monitoring System 

(NAHMS) conducted a study of U.S equine operations. 

The Equine 2005 study collected data on equine health 

and management practices from a representative 

sample of operations with 5 or more equids in 28 States 

divided into four regions.* The 28-State target population 

represented 78.0 percent of equids and 78.6 percent of 

operations with 5 or more equids in the United States. 

Interviews were conducted from July 18 through August 

12, 2005, and 2,893 equine operations provided data on 

equine health and management. 

 More than 9 of 10 operations (95.6 percent) had fullsize horses and 1 of 3 operations (34.8 percent) had 

equids other than full-size horses. For this study, a 

resident equid was defined as an equid that spent or 

was expected to spend more time at the operation than 

at any other operation during the previous 12 months. 

 The following are highlights excerpted from Part I of 

the NAHMS Equine 2005 study: Baseline Reference of 

Equine Health and Management, 2005. Released in 

November 2006, this report provides participants, 

industry, and animal-health officials with information on 

the Nation’s equine population that will serve as a basis 

for education, service, and research related to equine 

infectious disease control. 

Vaccinations 

 Overall, 75.9 percent of operations had given at least 

some type of vaccine to resident equids during the 

previous 12 months. A higher percentage of operations 

in the West region (83.8 percent) had given at least 

some vaccines to resident equids compared to 

operations in the South and Northeast regions (72.3 

percent and 72.0 percent, respectively) (table 1). 

_______________________ 

*Regions: 

West: California, Colorado, Montana, New Mexico, Oregon, 

Washington, and Wyoming

Northeast: New Jersey, New York, Ohio, and Pennsylvania

South: Alabama, Florida, Georgia, Kentucky, Louisiana, 

Maryland, Oklahoma, Tennessee, Texas, and Virginia 

Central: Illinois, Indiana, Kansas, Michigan, Minnesota, Missouri, 

and Wisconsin.

Table 1. Percentage of operations that administered 

any vaccine to resident equids during the previous 

12 months, by region:

 

Percent Operations 

Region 

South Northeast West Central 

All 

Operations

Percent Percent Percent Percent Percent 

72.3 72.0 83.8 77.4 75.9 

Foal deaths 

 Overall, 4.9 percent of foals born alive died in the first 

30 days. The percentage of foals that died in the first 2 

days and the percentage that died in the subsequent 28 

days (age 3 to 30 days) were similar (2.6 percent and 

2.3 percent, respectively); thus the likelihood of a foal 

dying based on days at risk was higher in the early 

neonatal period, i.e., birth to 2 days of age. The mortality 

rates in foals less than or equal to 30 days of age were 

similar across regions. 

 For foals that were born alive but died in the first 30 

days, 18.6 percent died due to injury/wounds/trauma 

(not related to birth), 17.9 percent died from unknown 

causes, and 14.9 percent died because they failed to get 

colostrum or milk from the mare. Dystocia, trauma, or 

complications at birth; birth defects; and other digestive 

problems were also frequently reported causes of death. 

“Other” causes of death included predator attacks and 

adverse environmental conditions (table 2). 
United States Department of Agriculture • Animal and Plant Health Inspection Service • Safeguarding American Agriculture 

Table 2. For foals born alive, percentage of foals that 

died during the first 30 days, by cause of death: 

Cause of Death Percent Foal Deaths 

Colic 1.5 

Other digestive 

problems (e.g., diarrhea) 6.4 

Respiratory problems 

(e.g., pneumonia, strangles, 

Rhodococcus equi, etc.) 3.6 

Neurologic problems (e.g., 

spinal problem, wobblers, 

seizure, EPM, WNV, sleeping 

sickness, maladjustment 

syndrome) 0.5 

Dystocia, trauma, 

or complications at birth 10.7 

Birth defects 8.9 

Injury/wounds/trauma 

unrelated to birth 18.6 

Infectious disease unrelated to 

specific body system, blood 

infection (septicemia) 3.3 

Failed to get colostrum 

or milk from mare 14.9 

Other 13.7 

Unknown 17.9 

Total 100.0 

Equid deaths 

 Total deaths ranged from 2.8 percent in the Northeast 

region to 1.6 percent in the South region during the 

previous 12 months. The overall mortality rate for 

resident equids more than 30 days of age was 1.8 

percent. The mortality rates for equids more than 30 

days of age to less than 20 years of age were similar. As 

expected, the highest mortality rates among resident 

equids over 30 days of age occurred in equids 30 years 

or older followed by equids 20 to less than 30 years of 

age (figure 1). 

0

10

20

30

40

50

1.2 1.1 1.2

6.7

45.7

1.8

More than 30 

days but less 

than 6 months

6 months 

to less than

5 years

5 years to

less than

20 years

20 years to

less than

30 years

30 years 

or older

Percent

Age

Figure 1. Percentage of Resident Equids More Than 30 Days of Age That 

Died or Were Euthanized During the Previous 12 Months, by Age 

 The leading causes of death were old age (28.9 

percent of deaths), injury/wounds/trauma (16.3 percent 

of deaths), and colic (14.6 percent of deaths) for equids 

more than 30 days of age. Lameness, leg, or hoof 

problems accounted for 7.7 percent of deaths. The 

remaining 32.5 percent included 6.6 percent attributed to 

unknown causes and individual specified causes—each 

of which accounted for less than 7 percent of total 

deaths—such as cancer, digestive problems other than 

colic, neurologic problems, etc. (figure 2). 

All other/unknown

Old age

Lameness, leg, or 

hoof problems

Injury/wounds/

trauma

Colic

14.6%

16.3%

7.7%

28.9%

32.5%

 Cause of Death

Figure 2. Percentage of Equid Deaths (Including Euthanasia) for Equids 

Aged More than 30 Days, by Cause of Death
United States Department of Agriculture • Animal and Plant Health Inspection Service • Safeguarding American Agriculture 

Direct contact with outside equids during trips 

For operations that had resident equids that left the 

home operation and returned after direct contact with 

outside equids, the percentage of operations that used 

infection-control practices for returning equids increased 

as operation size increased. More than half of large 

operations isolated or quarantined returning resident 

equids—either routinely or due to disease or exposure to 

disease—compared to less than one-third of small 

operations (figure 3). 

0

20

40

60

80

100

Never isolate returning equids

Quarantine before arrival at 

home operation 

Only isolate returning equids for cause

Routinely isolate returning equids

Percent Practice

Size of Operation (Number of Equids)

Figure 3. For Operations that had Resident Equids that Left the Home 

Operation and Returned After Direct Contact with Outside Equids, 

Percentage of Operations by Infection-Control Practice Used for 

Returning Equids, and by Size of Operation

9.6

22.4

2.3

65.7

11.5

30.5

2.9

55.1

14.5

35.9

5.2

44.4

Small (5 to 9) Medium (10 to 19) Large (20 or more)

For more information, contact: 

USDA:APHIS:VS:CEAH 

NRRC Building B, M.S. 2E7 

2150 Centre Avenue 

Fort Collins, CO 80526-8117 

970.494.7000 

E-mail: NAHMS@aphis.usda.gov 

http://nahms.aphis.usda.gov

#N467.1106

____________________________________

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Photos: USDA photo library