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VACCINATION TALK:

TIME-SAVING COMMUNICATION TIPS FOR BREEDING AND FOALING SEASONCONTENT SPONSORED BY MERCK

This quick guide to client-friendly vaccination information will help you cut visit times without cutting conversation that’s critical to mare and foal health.

BY BRYANT CRAIG, DVM,MERCK ANIMAL HEALTH EQUINE VETERINARY PROFESSIONAL SERVICES

Vaccination ins and outs may be second nature to you, but clients could have plenty of questions,

especially when it comes to vaccinating broodmares and foals. Even with an important topic like

this, your time talking with clients may get cut short during this busy time of year. Set yourself up for

effi cient – eff ective – conversations by proactively addressing common client queries. This handy

client-focused guide gives you a starting point for quick, critical vaccination information to share this

breeding and foaling season.

continued

OVERALL VACCINATION MESSAGE FOR CLIENTSWhether breeding or preparing for

delivery, vaccination plays a critical role

in maintaining the mare’s health and

protecting her unborn foal. Foals also

need a customized vaccination protocol

to protect their health.

PRIOR TO BREEDING: CORE AND AT-RISK VACCINESBefore breeding, make sure your mare

is current on all core vaccines. Core

vaccines, as defi ned by the American

Association of Equine Practitioners, are

justifi ed for use in all horses because

of their clearly demonstrated effi cacy

and safety along with their high level

of benefi t and low level of risk. Core

vaccines for all horses include:

♦ Eastern equineencephalomyelitis (EEE)

♦ Western equineencephalomyelitis (WEE)

♦ West Nile virus (WNV)

♦ Tetanus

♦ Rabies (should be administeredpre-breeding or pre-foaling)

For risk-based vaccines, ensure your

mare is current on equine infl uenza virus

(EIV) and equine herpesvirus types 1

and 4 (EHV-1&4). The need to vaccinate

against Streptococcus equi (strangles),

Potomac horse fever (PHF) and equine

viral arteritis (EVA) is determined on a

horse-by-horse basis.

DURING GESTATIONEHV-1 vaccination is a crucial

safeguard for your mare’s

pregnancy, since EHV-1 is the

leading cause of infectious viral

abortions in mares. To reduce the

risk of EHV-1 abortion, vaccinate

your mare with Prestige® Prodigy®

at the start of the fi fth, seventh and

ninth months of gestation. All horses

in close contact with broodmares,

including barren mares, stallions

and teaser stallions, should also

be maintained on a rigorous EHV-1

vaccination program. Reduce your

pregnant mare’s exposure to groups

of young horses and any new

arrivals that may be shedding EHV-1.

More in-depth EHV-1 info: EHV-1

is typically associated with late-

term abortions and the delivery of a

well-preserved fetus and outwardly

normal placenta. Most horses become

infected with EHV-1 during the fi rst

year of life. In the majority of cases,

the virus becomes latent, just waiting

for stress-induced reactivation.

Sources of infection for pregnant

broodmares include clinically ill

horses shedding the virus in nasal

secretions; asymptomatic horses

experiencing reactivation of latent

infection; or virus-laden uterine

secretions and placenta/fetus from

mares aborting due to EHV-1 infection.

Vaccination plays a critical role in maintaining the mare’s health and protecting her unborn foal.

Administering booster vaccinations 4 to 6 weeks before foaling is

important for stimulating the mare

to produce high levels of protective

antibodies at a time during late

pregnancy when she is also producing

antibody-rich colostrum. The newborn

foal relies on ingestion of colostrum

and absorption of these antibodies

during the first 12 to 24 hours of life for

protection against a wide variety of viral

and bacterial diseases during the early

post-natal period.

Booster your mare for equine

herpesvirus (EHV-1&4), Eastern and

Western encephalomyelitis (EEE/WEE),

tetanus, influenza and West Nile virus

(Prestige® 5+WNV). Also add rabies if

not administered pre-breeding.

5 months of gestation

7 months of gestation

8 months of gestation

9 months of gestation

10 months of gestation (pre-foaling)

▲

Quick Guide to Vaccinating During Gestation1

EHV-1 (reproductive protection)

EHV-1 (reproductive protection)

EHV-1 (reproductive protection)

Rabies (if not given pre-breeding), EWT, WNV, EIV, EHV-1&4 (respiratory protection)

▲▲

▲

▲

Gestation Period Core Vaccines At-Risk Vaccines*

Rotavirus first dose (3-dose series)Botulism first dose, if mare is not current (3-dose series)

Rotavirus second dose Botulism second dose

Rotavirus third dose Botulism third dose Strangles intramuscular (IM) Potomac horse fever

*Client reminder: Vaccinations against strangles, Potomac horse fever, botulism

and rotavirus are recommended only if there is a high risk of disease in your region

or on your farm. If your mare will be sent to another farm for re-breeding, consider

the risk of disease on that farm to plan vaccinations accordingly.

FOAL VACCINATION 101 FOR CLIENTSWhen foals are born, they inherit

immediate disease protection through

the vaccinated dam’s colostrum. But

eventually those maternal antibodies

decline, and foals need the added

protection that only comes through

proper immunization. Preventing

disease through a strategic vaccination

program is safer, easier and more

economical than treating a sick foal.

Customized vaccination schedules

are important. The recommended

schedule takes into account your

region of the country, endemic

diseases on your farm and your foal’s

risk of disease exposure. Risk factors

include how many other mares and

foals your foal will contact during the

first year of life and whether your foal

will remain on your farm or travel to

other locations when his dam is rebred

or he is sent for training.

2-3 months

4-6 months

6 months

6-9 months

10-12 months

▲

Quick Guide to Recommended Foal Vaccination Timing2

EEE/WEE, tetanus, WNV (3-dose series); second dose 4-6 weeks later

Rabies first dose (2-dose series); second dose 4-6 weeks later

EEE/WEE, tetanus, WNV third dose

▲

▲

▲

▲

Age Core Vaccines At-Risk Vaccines*

Botulism first dose (3-dose series)

EHV-1&4 is recommended for all foals: EHV-1&4 first dose (3-dose series); second dose 4-6 weeks later Strangles, killed vaccine, intramuscular first dose (3-dose series)

Potomac horse fever first dose (3-dose series); second dose 4-6 weeks later

Equine influenza recommended for all older weanlings and yearlings:♦ Killed vaccine, intramuscular first dose

(3-dose series); second dose 4-6 weeks later♦ Modified live vaccine, intranasal first dose

(2-dose series)Strangles, modified live vaccine, intranasal first dose (3-dose series); second dose 3-4 weeks later

EHV-1&4 third dose Strangles, modified live vaccine, intranasal third dose Equine influenza♦ Killed vaccine, intramuscular third dose♦ Modified live vaccine, intranasal second dosePotomac horse fever third dose (at 12 months)

*Client reminder: Risk-based vaccines will be included in your foal’s customized

vaccination schedule based on your farm location and history, as well as the

foal’s lifestyle.

800.279.6452

This product has been shown to be e� ective for the vaccination of healthy horses 6 months of age or older against abortion and respiratory disease caused by EHV-1. Duration of immunity has not been established. For more information regarding safety and e� cacy data, go to productdata.aphis.usda.gov.

COPYRIGHT © 2020 INTERVET INC., D/B/A MERCK ANIMAL HEALTH, A SUBSIDIARY OF MERCK & CO., INC.

References

1. Adapted from AAEP core and risk-based vaccinationguidelines for broodmares (www.aaep.org).

2. Adapted from AAEP core and risk-based vaccinationguidelines for foals (www.aaep.org).

Timing of the fi rst vaccinations

is critical. The maternally derived

colostral antibodies that provide

the foal with temporary protection

are the same antibodies that

prevent the foal from mounting

an acceptable immune response

to vaccines that are administered

too early. Around 4 to 6 months of

age, foals are ready for their fi rst

core vaccinations (if their dam had

been vaccinated).

PARTING NOTE FOR VETERINARIANSClient communications are a critical part of

what you do every day. When it comes to

educating and preparing horse owners for

what to expect when it comes to vaccination,

you’re in the driver’s seat. It’s a busy time of

year, but with good health that leads to good

outcomes, the work is well worth it.