Form A: Premises Level Questionnaire 

This questionnaire consists of questions about the premises at which the EHM index case was 

identified. These questions will help identify potential EHM risk factors for both the index case 

and subsequent cases of EHM. 

Abbreviations for this questionnaire: 

 

EHV-1: Equine herpesvirus-1 

EHM: Equine herpesvirus myeloencephalopathy 

Y=Yes, N=No, D/K=Don’t know, NA=Not applicable 

Definitions for this questionnaire: 

 

Equid: All species of equid such as donkeys, mules, ponies, horses, etc. 

Horse: All full-size horse breeds (14 hands or more at withers) including foals on the premises 

(does not include donkeys, mules, ponies, and miniatures). 

Resident equid: Equids, including foals, which have spent or are expected to spend more time 

at this premises than at any other premises, even if not owned by the owner of the premises. 

In other words, this premises may be considered the animal’s “home.” 

Nonresident equine: Not a resident equid as describe by the definition above. 

Isolate: To prevent nose-to-nose contact with other equids from this premises, prevent the 

sharing of equipment such as brushes, combs, and buckets between equids, and establish 

the practice of hygienic methods for personnel. 

In the last 30 days: Includes the past 30 days from the date of this interview. When asked 

about a resident equid in the last 30 days, consider equids that may no longer be on the 

premises. 

Premises identification ________________________________________ 

Date of data collection: __/__/__ 
SECTION 1: FUNCTION 

1. What do you consider the primary function of this premises? (Circle one.) 

 1–Boarding stable/training 

 2–Riding stable (lessons, rent equids, etc.) 

 3–Racetrack 

 4–Equine breeding farm 

 5–Farm or ranch 

 6–Residence with equids for personal use (show, pleasure, etc.) 

 7–Show grounds (e.g., pleasure, equitation, halter, conformation, showmanship) 

 8–Western event (e.g., barrel racing, team penning, roping, cutting) 

 9–Polo match 

 10–Fairgrounds 

 11–Rodeo 

 12–Trail ride 

 13–Sale or auction 

 14–Training clinic 

 15–Draft horse pull/show 

 16–Horse trials/eventing (including dressage, cross-country, and show jumping) 

 17–Other (specify: ____________________________________) 

2. What do you consider to be the primary use of the equids currently on this premises? 

(Circle one.) 

 1–Pleasure 

 2–Lessons/school 

 3–Showing/competition (not betting) 

 4–Breeding 

 5–Racing 

 6–Farm or ranch work 

 7–Other (specify: ________________) 

SECTION 2: POPULATION 

1. How many equids have been considered residents at the premises in the last 30 days? 

 1–Horses (excluding miniature horses) #________head 

 2–Mules #________head 

 3–Miniature horses #________head 

 4–Donkeys or burros #________head 

 5–Ponies #________head 

 6–Other equids, (specify: __________________) #________head 

 7–Total (add items1–6) #________total 

 If Total Head=0, skip to Question 5. 

2. a. Did you add any new resident equids to the premises in the last 30 days (excluding 

 births to resident mares)? Y N D/K 

 

 If “No” or “Don’t know,” skip to Question 4. 
 b. How many new resident equids were added to the premises in the last 30 days? 

# _______head 

 c. How many of the equids added came from: 

 1–Within State #________head 

 2–Outside State, within U.S. #________head 

 3–Canada #________head 

 4–Mexico #________head 

 5–Outside North America #________head 

 6–Unknown location #________head 

 7–Total items (add items 1–6) #________total 

 

 d. For the majority of these new resident equids, did you (this premises) 

 always require (1), sometimes require(2), or never require(3): 

 

 Always Sometimes Never

 1–Official health certificate 1 2 3 

 2–Veterinary examination other than for 

 official health certificate 1 2 3 

 3–Equine herpes vaccination within 

 the past year 1 2 3 

 4–Quarantine or isolation prior to contact 

 with resident equine 1 2 3 

3. a. Did you permanently remove any resident equids from the premises in the last 30 

 days (including deaths)? Y N D/K 

 

 If “No” or “Don’t know,” skip to Question 5. 

 b. Why were these equids removed from the premises? 

 1–Died (not euthanized) #________head 

 2–Euthanized #________head 

 3–Sold or traded #________head 

 4–Other (specify) #________head 

4. a. How many nonresident equids have visited or been stabled at the premises in the 

 last 30 days? 

 

 1–Horses (excluding miniature horses) #________head 

 2–Mules #________head 

 3–Miniature horses #________head 

 4–Donkeys or burros #________head 

 5–Ponies #________head 

 6–Other equids (specify: ________________) #________head 

 7–Total (add items1–6) #________head 

 If # head=0, skip to Question 6. 

 
 b. For the majority of these nonresident equids, did you (this premises) 

 always require(1), sometimes require(2), or never require(3): 

 Always Sometimes Never

 1–Official health certificate 1 2 3 

 2–Veterinary examination other than for 

 official health certificate 1 2 3 

 3–Equine herpes virus vaccination within 

 the past year 1 2 3 

 4–Quarantine or isolation prior to contact 

 with resident equine 1 2 3 

5. Have there been any dynamic changes for the equids on the premises in the last 30 days? 

(Circle all that apply.) 

 1–No change in dynamics 

 2–Weaning 

 3–Fighting 

 4–Changing of members within groups 

 5–Construction on premises 

 6–Other (specify: __________________________________________)

SECTION 3: HEALTH 

1. Prior to this outbreak of equine herpesvirus-1, how often did you check the body 

temperature on healthy equids (nonsymptomatic of an infectious disease)? (Circle one.) 

 1–Never 

 2–Less than once a day 

 3–Once a day 

 4–Twice a day 

 5–Other (specify: ___________________________________) 

2. How often did you check the body temperature on an equid with signs of an infectious 

disease such as equine herpesvirus-1 prior to this outbreak? (Circle one.) 

 1–Never 

 2–Once a day 

 3–Twice a day 

 4–Other (specify: ___________________________________) 

3. Since this outbreak of equine herpesvirus-1, how often do you check the body temperature 

on healthy equids (no clinical signs of an infectious disease)? (Circle one.) 

 1–Never 

 2–Once a day 

 3–Twice a day 

 4–Other (specify: ____________________________________) 
4. Since this outbreak of equine herpesvirus-1, how often are you checking body temperatures 

in equids with signs of an infectious disease? 

 1-Never 

 2-Once a day 

 3-Twice a day 

 4-Other (Specify: ____________________________________) 

5. How many pregnant mares were on this premises in the last 30 days? 

 #________head 

6. In the last 30 days, how many mares aborted or had stillborn foals? 

 #________head 

In the next question, signs of acute upper respiratory infection must include a cough and/or 

nasal discharge (serous or mucoid) and at least one of the following: fever, malaise, off feed or 

decreased appetite, purulent nasal discharge, or enlarged lymph nodes on head or around the 

upper neck. 

7. a. In the last 30 days, how many resident equids became ill with acute upper respiratory 

 infection? 

 #________head 

 b. In the last 30 days, how many nonresident equids became ill with acute upper 

 respiratory infection? 

 #________head 

If # head=0, skip to Section 4. 

8. Of these equids that became ill with acute upper respiratory infections, how many were the 

following age categories at the time they became ill? 

 Resident Nonresident

 1–Foals less than 6 months old #________head #________head 

 2–6 months up to 18 months old #________head #________head 

 3–18 month up to 5 years old #________head #________head 

 4–5 years up to 20 years old #________head #________head 

 5–20 years and older #________head #________head 

 6–Total (add items 1–5) #________head #________head 
SECTION 4: BIOSECURITY 

1. Which of the following best describes how far it is from this premises to the nearest premises 

with any type of equids? (Circle one.) 

 1–Adjacent 

 2–Less than 200 yards 

 3–200 yards to 1 mile 

 4–1 mile to 5 miles 

 5–200 yard to 5 miles 

 6–More than 5 miles 

 7–Don’t know 

2. Which of the following best describes the premises’ general practice when resident equids 

leave the premises, have direct contact with nonresident equids and return? (Circle one.) 

 1–Resident equids never leave premises or never have contact with nonresident 

 equids 

 2–Routinely isolate for at least 14 days after return to home premises 

 3–Only isolate for a cause such as disease or known exposure to disease 

 4–Routinely isolate before return to home premises 

 5–Never isolate returning equids 

 6–No resident equids on premises (e.g., equine event premises) 

3. For infection control, do you ever require people (visitors, veterinarian, farrier, etc.) coming 

onto the equine premises to do any of the following? (Circle all that apply.) 

 1–Use separate or disinfected equipment 

 2–Change clothes or wear clean coveralls 

 3–Disinfect or change boots 

 4–Clean and disinfect their hands 

 5–Park vehicles away from animal area 

 6–Other (specify: _____________________________________) 

4. a. Do you have a separate area designated for isolation or infection control? 

Y N D/K 

 If “No” or “Don’t know,” skip to Question 5. 

 b. In the last 30 days have you moved any equids with signs of equine herpesvirus-1 to 

this separate isolation area? Y N D/K 

c. Where is this separate area located? (Circle one.) 

 1–Separate building 

 2–Same building away from other equids but common airspace 

 3–Same building, away from other equids with separate airspace 

 4–Other (specify:_________________________) 

 
 d. Do you restrict movement of personnel working with the animals in isolation? 

Y N D/K 

 

 If “Yes,” specify how: ____________________________________________________ 

 

5. In the last 30 days, have any of the following insect control methods been used? 

(Circle all that apply.) 

 1–Repellents applied to equids 

 2–Insecticides applied to in or near equine housing area 

 3–Insecticides applied to pasture areas 

 4–Sticky tape 

 5–Bug zapper 

 6–Fly mask on equid 

 7–Fly tags attached to equine halters 

 8–Fly sheets on equids 

 9–Other (specify: __________________________________) 

6. Which of the following best describes how much time the majority of the resident equids 

spent confined indoors in the last 30 days? (Circle one.) 

 1–Never or rarely 

 2–Half the time or less 

 3–More than half the time 


Form C: EHM Index Case Questionnaire 

This questionnaire pertains only to the EHM index case. General background information was 

collected on the index case on Form B, but this questionnaire will help identify potential EHM 

risk factors for the index case. 

Abbreviations for this questionnaire: 

 

EHV-1: Equine herpesvirus-1 

EHM: Equine herpesvirus myeloencephalopathy 

Y=Yes, N=No, D/K=Don’t know, NA=Not applicable 

Definitions for this questionnaire: 

Index case: The first equid on the premises with neurological signs consistent with EHM and a 

positive biological test for EHV-1. 

Equid: All species of equids such as donkeys, mules, ponies, horses, etc. 

Horses: All full-size horse breeds (14 hands or more at withers) including foals on the premises. 

Does not include donkeys, mules, ponies, and miniatures. 

In the last 30 days prior to the onset of EHM: Include the 30 days before the date that the 

equid presented with neurological signs of EHM. 

The following questions pertain only to the equid identified as the Index Case: 

Index Case Name or ID: __________________________ 

Today’s Date __/__/__ Date of onset of EHM:__/__/__ 
SECTION 1: HEALTH 

This section relates to the clinical health and medical treatments of the index case prior to EHM

diagnosis and after EHM diagnosis. To answer these, please refer to the equid’s medical 

records. 

1. Use the chart below to describe any clinical signs the equid exhibited within the last 30 days 

prior to the onset of EHM. If you answer Yes, please list the date of onset of the clinical sign. 

2. Use the chart below to describe all neurological signs the equid initially exhibited at the 

onset of EHM. Check all that apply and indicate which neurological sign appeared first. 

Initial neurological signs 

Check all that apply 

and circle first sign 

Complete recumbency (cannot rise with assistance) 

Incomplete recumbency (can rise with assistance) 

Hind limb ataxia 

Front limb ataxia 

Toe dragging 

Paresis 

Head tilt 

Circling 

Bladder atony 

Reduced tail tone 

Reduced anal tone 

Other (specify) 

3. a. Has this equid received any type of medication in the last 30 days prior to the onset 

 of EHM? Y N D/K 

 If “No” or “Don’t know,” skip to Question 4. 

Clinical sign Answer Y, N, D/K 

Date of onset of 

clinical sign 

Fever (>101.5°F) 

 

Nasal discharge or 

cough 

 

Abortion 

 

Lethargy 

 

Leg edema 

 

Decreased appetite 

 

Injury/wounds/trauma 

 

Colic 

 

Lameness (severe 

enough to require 

treatment) 

 

Other (specify) 

 
b. Use the chart below to describe the medications administered to the equid in the last 

30 days prior to the onset of EHM. 

Medication type 

List name of medication or 

NA if not applicable 

Date of 

treatment 

onset 

Treatment 

duration in 

days 

Antivirals 

 

_____days 

NSAIDS _____days 

Corticosteroids _____days 

Antibiotics _____days 

Lasix/furosemide _____days 

Prerace jug _____days 

Joint injection _____days 

Dewormer _____days 

Vaccination(s) _____days 

Joint supplement(s) _____days 

Nutritional supplement(s) _____days 

Other (specify) _____days 

4 a. Has this equid received any type of medication after the EHM diagnosis? 

 Y N D/K 

 If “No” or “Don’t know,” skip to Question 5. 

b. Use the chart below to describe the medications administered to the equid after the 

EHM diagnosis. 

Medication type 

List name of medication 

or NA if not applicable 

Date of 

treatment onset 

Antivirals 

NSAIDS 

Corticosteroids 

Antibiotics 

Other (specify) 
5. Use the chart below to list the biological test(s) performed, the result(s) obtained, and the 

name of the testing laboratory responsible for processing the sample(s) for the index case. 

Biological test Check all that apply Results: see code Laboratory name 

Nasal PCR 

Blood PCR 

*Serologic titers 

**Histopathology 

Virus isolation 

***CSF analysis 

Other (specify) 

 

 *Positive serologic titer is a 4X rise in titers 2–4 weeks apart with no history of vaccination during that time. 

 ** Abnormal histopathology results include vasculitis and/or thrombosis of CNS blood vessels. 

 *** Abnormal CSF analysis consistent with EHM is an increase in total protein/albumin without an increase in nucleated 

 cell count and presence of xanthochromia. 

Result codes 

 1=Positive/abnormal result 

 2=Negative result 

 3=Unknown 

 4=Suspect or inclusive results 

6. Use the chart below to characterize the current clinical condition of the equid. 

Clinical Status 

Check the 

appropriate box 

Complete recovery 

Partial recovery 

Stable condition 

Condition deteriorating 

Died (not euthanized) 

Euthanized 

SECTION 2: EXPOSURE

The following questions pertain to the index case’s exposure prior to EHM diagnosis. 

1. Is the index case a resident of this premises? Y N D/K

2. Has the index case been directly exposed to nonresident equids the last 30 days? 

(Circle one.) 

 1–No 

 2–Yes, one nonresident exposure 

 3–Yes, more than one nonresident exposure 

 4–Don’t know 
3. Has the index case been indirectly exposed* to nonresident equids in the last 30 days? 

(Circle one.). 

[*Indirectly exposed, such as through shared equipment, shared transport, and/or personnel 

moving between horses.] 

 1–No 

 2–Yes, one nonresident exposure 

 3–Yes, more than one nonresident exposure 

 4–Don’t know 

4. Has the index case been directly or indirectly exposed to a mule or donkey in the last 30 

days? Y N D/K 

5. In the 30 days prior to the EHM diagnosis, approximately how many different people on a 

daily basis have had direct exposure to this equid (include stall cleaners, groomers, trainers, 

caretakers, veterinarians, farriers, etc.)? #________ or D/K 

SECTION 3: BIOSECURITY 

This section pertains to biosecurity practices that have taken place since EHV-1 was confirmed 

on the premises. 

1. Has the index case been isolated from the other equids on the premises since EHM was 

diagnosed? If “Yes,” list the date. Y date __/__/__ N D/K 

 

2. If “Yes,” has the index case been moved to a different housing area away from the healthy 

(nonsymptomatic) equids on the premises since EHM was diagnosed? If “Yes,” list the date. 

 Y date__/__/__ N D/K 

SECTION 4: NUTRITION 

1. Which of the following is the primary grain/concentrate fed to this equid in the 30 days prior 

to EHM diagnosis? (Circle one.) 

 

 1–Not fed (for example, hay or turned-out only) 

 2–Unpelleted sweet feed, such as grain mixed with molasses 

 3–Unpelleted grain, such as whole or rolled oats and corn 

 4–Geriatric feed 

 5–Complete feed pellets or cubes, such as a forage/grain mixture 

 6–Grain mix with pellets 

 7–Other (specify: ________________________) 

2. Which of the following is the primary dried forage fed to this equid in the 30 days prior to the 

EHM diagnosis? (Circle one.) 

 1–Not fed (for example, turned-out only) 

 2–Alfalfa 

 3–Grass hay 

 4–Grass and alfalfa mix hay 

 5–Other (specify: ________________________) 
3. Does this equid typically receive dietary supplements (e.g., folic acid, Vitamin E)? 

 Y N D/K 

 If “Yes,” please list the dietary supplement(s), the amount, and frequency of 

 administration: 

 ______________________________________________________________________ 

 ______________________________________________________________________ 

 ______________________________________________________________________ 

 ______________________________________________________________________ 

 ______________________________________________________________________ 

 ______________________________________________________________________ 

 ______________________________________________________________________ 

 ______________________________________________________________________ 
Form D: Questionnaire for Horses with Fever, Neurologic Signs, 

and Exposed to Index EHM Case at Initial Data Collection

This questionnaire pertains only to those equids that have been exposed to the index case and

have developed a fever and/or neurologic signs in the last 30 days. Exposed equids are those 

that have shared airspace and/or had direct physical contact with the index case. General 

background information was collected on each case on Form B, but this questionnaire will help 

identify potential EHM risk factors for new cases of EHM after the exposure to the index case. 

Abbreviations for this questionnaire: 

 

EHV-1: Equine herpesvirus-1 

EHM: Equine herpesvirus myeloencephalopathy 

Y=Yes, N=No, D/K=Don’t know, NA=Not applicable 

Definitions for this questionnaire: 

Equid: All species of equids such as donkeys, mules, ponies, horses, etc. 

Horse: All full-size horse breeds (14 hands or more at withers) including foals on the premises. 

Does not include donkeys, mules, ponies, and miniatures. 

In the last 30 days: Include the 30 days before the date of this interview. 

Resident equid: Equids including foals that have spent or are expected to spend more time at 

this premises than at any other premises, even if not owned by the owner of the premises. In 

other words, this premises may be considered the animal’s “home.” 

Nonresident equid: Not a resident equid as describe by the definition above. 

Direct exposure: Physical contact. 

Indirect exposure: Cared for by same personnel, shared equipment, or shared airspace. 

Index case: The first equid on the premises with neurological signs consistent with EHM, no 

epidemiological link to another equid with EHM, and a positive biological test for EHV-1. 

Isolate: To prevent nose-to-nose contact with other equids from this premises and the sharing 

of equipment, such as brushes, combs, and buckets between equids. 

The following questions pertain only to the equine case specified for this questionnaire: 

Equid name or ID: __________________________ 

Today’s date: ____/____/____ 
SECTION 1: HEALTH 

This section relates to the clinical health and medical treatments of this equid in the last 30 

days. To answer these, please refer to the equid’s medical records. 

 1. a. Has this equid had any of the following signs of EHV-1 disease (neurologic signs, 

 fever, lethargy, decreased appetite, etc.) in the last 30 days? 

 Y N D/K 

If “No” to neurologic signs, skip to Question 2. 

 b. Use the chart below to characterize EHV-1 disease signs the equid exhibited within 

 the last 30 days. 

c. Use the chart below to characterize the neurological signs this equid exhibited in the 

last 30 days. 

Neurological signs Check all that apply 

Complete recumbency (cannot 

rise with assistance) 

Incomplete recumbency (can 

rise with assistance) 

Hind limb ataxia 

Front limb ataxia 

Toe dragging 

Paresis 

Head tilt 

Circling 

Bladder atony 

Reduced tail tone 

Reduced anal tone 

Other (specify) 

Clinical sign Answer Y, N, D/K 

Date of onset of 

clinical sign 

*Neurologic signs 

 

Fever (>101.5°F) 

 

Nasal discharge 

or cough 

 

Abortion 

 

Lethargy 

 

Leg edema 

 

Decreased appetite 

 

Other (specify) 

 
2. a. Has this equid received any medication in the last 30 days for the treatment or 

prevention of EHV-1 Y N D/K 

 If “No” or “Don’t know,” skip to Question 3. 

 b. Use the chart below to list the medication(s) administered to the equid in the last 

 30 days for the treatment or prevention of EHV-1.

Medication type 

List name of medication 

or NA if not applicable 

Date of 

treatment 

onset 

Treatment 

duration in 

days 

Antivirals 

 

_____days 

NSAIDS _____days 

Corticosteroids _____days 

Antibiotic _____days 

Other (specify) _____days 

3. a. Has this equid received medications in the last 30 days for reasons other than 

 treatment or prevention of EHV-1? Y N D/K 

 

 If “No” or “Don’t know,” skip to Question 4. 

 b. Use the chart below to list the medication(s) administered to the equid in the last 

 30 days for reasons other than treatment or prevention of EHV-1. 

Medication type 

List name of medication 

or NA if not applicable 

Date of 

treatment 

onset 

Treatment 

duration in 

days 

Antivirals 

 

_____days 

NSAIDS _____days 

Corticosteroids _____days 

Antibiotic _____days 

Lasix/furosemide _____days 

Prerace jug _____days 

Joint injection _____days 

Dewormer _____days 

Vaccination(s) _____days 

Joint supplement(s) _____days 

Nutritional supplement(s) _____days 

Other (specify) _____days 

4. a. Has any biological testing been performed on this equid to determine 

 EHV-infectious status? 

 Y N D/K 

 If “No” or “Don’t know,” skip to Question 5. 

 
 b. Use the chart below to describe the biological test(s) and the result(s) that were used 

 to diagnose the equid with EHM. 

Biological test Check all that apply Results: see code Laboratory name 

Nasal PCR 

Blood PCR 

*Serologic titers 

**Histopathology 

Virus isolation 

***CSF analysis 

Other (specify) 

 * Positive serologic titer is a 4X rise in titers 2–4 weeks apart with no history of vaccination during that time. 

 ** Abnormal histopathology results include vasculitis and/or thrombosis of CNS blood vessels. 

 *** Abnormal CSF analysis consistent with EHM is an increase in total protein/albumin without an increase in nucleated 

 cell count and presence of xanthochromia. 

 

Result codes 

 1=Positive result/abnormal 

 2=Negative result 

 3=Unknown 

 4=Suspect or inconclusive results 

5. Use the chart below to characterize the current clinical condition of the equid. 

Clinical Status 

Check the 

appropriate box 

Complete recovery 

Partial recovery 

Stable condition 

Condition deteriorating 

Died (not euthanized) 

Euthanized 

SECTION 2: EXPOSURE

1. Is this equid a resident of this premises? Y N D/K 

2. Has this equid been directly exposed to nonresident equids in the last 30 days? 

(Circle one.) 

 

 1–No 

 2–Yes, one nonresident exposure 

 3–Yes, more than one nonresident exposure 

 4–Don’t know 
3. Has this equid been indirectly exposed to nonresident equids the last 30 days? 

(Circle one.) 

 1–No 

 2–Yes, one nonresident exposure 

 3–Yes, more than one nonresident exposure 

 4–Don’t know 

4. Has this equid been directly or indirectly exposed to a mule or donkey in the last 30 days? 

 Y N D/K 

 

5. Prior to the EHV-1 outbreak, approximately how many people on a daily basis had direct 

exposure to this equid (include stall cleaners, grooms, trainers, caretakers, veterinarians, 

farriers, etc.)? 

 #__________ or D/K 

6. Has this equid had direct exposure to the index case in the last 30 days? 

 Y N D/K 

7. Has this equid had indirect exposure to the index case in the last 30 days? 

 Y N D/K 

SECTION 3: BIOSECURITY 

This section pertains to biosecurity practices that have taken place since EHV-1 was confirmed 

on the premises. 

 

1. Has this equid been isolated from the other equids on the premises since EHV-1 was first 

confirmed on the premises? If “Yes,” list the date. 

 Y date __/__/__ N D/K 

 

SECTION 4: NUTRITION 

1. Which of the following was the primary grain/concentrate fed to this equid in the last 30 

days? 

(Circle one.) 

 

 1–Not fed 

 2–Unpelleted sweet feed, such as grain mixed with molasses 

 3–Unpelleted grain, such as whole or rolled oats and corn 

 4–Geriatric feed 

 5–Complete feed pellets or cubes, such as a forage/grain mixture 

 6–Grain mix with pellets 

 7–Other (specify: _________________) 
2. Which of the following was the primary dried forage fed to this equid in previous 30 days? 

 1–Not fed 

 2–Alfalfa 

 3–Grass hay 

 4–Grass and alfalfa mix hay 

 5–Other (specify: _________________) 

3. Does this equid typically receive dietary supplements (e.g., folic acid, vitamin E)? 

 Y N D/K 

 

If “Yes,” please list the dietary supplement(s), the amount, and frequency of 

 administration. 

 ______________________________________________________________________ 

 ______________________________________________________________________ 

 ______________________________________________________________________ 

 ______________________________________________________________________ 

 ______________________________________________________________________ 

 ______________________________________________________________________ 

 ______________________________________________________________________ 

 ______________________________________________________________________ 

 


Form F: Followup Questionnaire for the Index Case, 

Subsequent EHV Cases, and Controls 

This questionnaire is to be filled out for the index case, subsequent cases/potential subsequent 

cases, and randomly selected controls at the end of the EHV-1 outbreak (28 days after the last 

EHV-1 case is diagnosed). The subsequent cases and potential subsequent cases are all 

equids that have been exposed to the index case and have developed a fever and/or neurologic 

signs since the start of the EHV-1 outbreak. There should be three controls per case, which 

should be randomly selected at the end of the outbreak. General background information was 

collected on each equid on Form B, but this questionnaire will help identify potential EHM risk 

factors for the index case and for other equids exposed to the index case. 

Abbreviations for this questionnaire: 

 

EHV-1: Equine herpesvirus-1 

EHM: Equine herpesvirus myeloencephalopathy 

Y=Yes, N=No, D/K=Don’t know, NA=Not applicable 

Definitions for this questionnaire: 

Equid: All species of equids such as donkeys, mules, ponies, horses, etc. 

Exposed equids: Those that have shared airspace and/or had direct physical contact with the 

index case. 

Horses: All full-size horse breeds (14 hands or more at withers) including foals on the premises. 

Does not include donkeys, mules, ponies, and miniatures. 

In the last 30 days prior to the onset of EHM: Include the 30 days before the date that the 

equid presented with neurological signs of EHM. 

Randomly selected controls: Equids that have been exposed to the index case, but have not 

developed a fever and/or neurologic signs. 

The following questions pertain only to the equid previously specified for this 

questionnaire: 

Equid name or ID: __________________________ 

Today’s date: ___/___/___ 

Indicate status of this equid (circle one): 

 

 Index case Subsequent EHV case in this outbreak Control 

This questionnaire relates to the clinical health and medical treatments of this equid. To answer 

these, please refer to the equid’s medical records. 

1. Was this equine diagnosed with EHV-1 infection? 

 Y N D/K 

 If “No,” skip to Question 6. 
2. Was this equid diagnosed with EHM? 

 Y N D/K 

3. a. Has this equid shown any signs of EHV-1 disease (neuropathy, fever, lethargy, 

 decreased appetite, etc.) in the last 30 days? 

 Y N D/K 

 If “No” or “Don’t know,” skip to Question 6. 

 b. Use the chart below to characterize the clinical signs of EHV-1 observed in the 

 equid. 

Clinical sign Answer Y/N 

Date of onset of 

clinical signs 

Fever (>101.5°F) 

 

Respiratory disease 

 

Neurologic disease 

 

Abortion 

 

Lethargy 

 

Leg edema 

 

Other (specify) 

 

 If “No” to fever, skip to Question 5. 

4. a. How many days did the elevated body temperature last on the equid? (Circle one.) 

 1–2 days 

 3–4 days 

 5–6 days 

 ≥7 days 

 b. What was the date the of the peak body temperature?__/__/__ 
5. a. Did this equid have any neurological signs since the start of the EHV-1 outbreak? 

 (can refer to 3b.) Y N D/K 

 

 If “No” or “Don’t know,” skip to Question 7. 

 b. Use the chart below to characterize the neurological signs observed in this equid. 

Neurological signs Check all that apply 

Complete recumbency (cannot rise with assistance) 

Incomplete recumbency (can rise with assistance) 

Hind limb ataxia 

Front limb ataxia 

Toe Dragging 

Paresis 

Head tilt 

Circling 

Bladder atony 

Reduced tail tone 

Reduced anal tone 

Other (specify) 

 

6. a. Has this equid received any medication since the date of the first questionnaire for 

treatment or prevention of EHV-1? 

 Y N D/K 

 

 If “No” or “Don’t know,” skip to Question 7. 

 b. Use the chart below to list the medication(s) administered to the equid for the

 treatment or prevention of EHV-1 since the date of the first questionnaire. 

Medication type 

List name of medication 

or NA if not applicable 

Date of treatment 

onset 

Antivirals 

NSAIDS 

Corticosteroids 

Antibiotic 

Other (specify) 

7. a. Has the equid received any medication since the date of the first questionnaire for 

 reasons other than the treatment of EHV-1? 

 Y N D/K 

 If “No” or “Don’t know,” skip to Question 8. 

 
b. Use the chart below to describe any type of medication the equiD has received since the 

date of the first questionnaire other than the treatment or preventions or EHV-1. 

Medication type 

List name of medication 

or NA if not applicable 

Date of initial 

treatment 

Treatment 

duration in 

days 

Antivirals 

 

_____days 

NSAIDS _____days 

Corticosteroids _____days 

Antibiotic _____days 

Lasix/furosemide _____days 

Prerace jug _____days 

Joint injection _____days 

Dewormer _____days 

Vaccination(s) _____days 

Joint supplement(s) _____days 

Nutritional supplement(s) _____days 

Other (specify) _____days 

8. a. Has this equiD had any biological test to determine EHV-infectious status? 

 Y N D/K 

 

 If “No” or “Don’t know,” skip to Question 9. 

 b. Use the chart below to list the biological test(s) performed, the results obtained, and 

 the name of the testing laboratory responsible for processing the sample(s) to diagnose 

 EHM in the equid. 

Biological Test Check all that apply Results: see code Laboratory name 

Nasal PCR 

Blood PCR 

*Serologic titers 

**Histopathology 

Virus isolation 

***CSF analysis 

Other (specify) 

 * Positive serologic titer is a 4X rise in titers 2–4 weeks apart with no history of vaccination during that time. 

 ** Abnormal histopathology results include vasculitis and/or thrombosis of CNS blood vessels. 

 ***Abnormal CSF analysis consistent with EHM is an increase in total protein/albumin without an increase in nucleated 

 cell count and presence of xanthochromia. 

Result codes 

 1=Positive result/abnormal 

 2=Negative result 

 3=Unknown 

 4=Suspect or inconclusive results 
9. What was the medical outcome of this equid? 

Clinical outcome 

Check the 

appropriate 

row 

Date of 

outcome 

No signs of EHV-1 throughout outbreak 

Complete recovery 

Improved but not completely recovered 

Died (not euthanized) 

Euthanized 

Outcome other than those listed 

(specify)______________________________________________