Page 106 - January 2017

VACCINATING BROODMARES
AND FOALS
by Heather Smith Thomas
tetanus, West Nile, influenza, and rabies, and another vaccination booster for EHV-1. These are diseases that foals may be exposed to in the first months of life, and if we vaccinate the mares during the last 4
to 6 weeks of gestation, that gives the mare time to produce antibodies and have a high titer. This enables
the mares to produce a high level of antibodies in their colostrum,” she explains. “We are essentially try- ing to boost the mare’s antibody titers so she can pass this protection to the foal via the colostrum.”
There are some other vaccines that are risk-based, that target certain foal diseases. If foals are at high risk for encountering and developing these diseases, you could vaccinate the mares—so they can pass
the antibodies to the foals in their colostrum. “One of these diseases is botulism, which can affect foals.
Dr. Katherine Wilson, a Clinical Assistant Professor of Large Animal Medicine, says that
vaccinating mares for Equine Herpes Virus-1 (EHV-1) is especially important since it can cause abortions in mares. Vaccinating with core vaccines in the last 4-6 weeks of gestation
will give the mare time
to produce a high level of antibodies in her colostrum.
There is not really a set protocol for all situations and all foals.
Vaccination is one of our best tools for protect- ing young foals from disease, and the best protection for foals begins with vaccinating broodmares at strategic times during pregnancy. This results in passive transfer of antibodies to the foal through colostrum, if the foal ingests an adequate amount of colostrum shortly after birth. It is also important to vaccinate pregnant mares against dis- eases that could cause abortion.
VACCINATING MARES
Dr. Katherine Wilson (Clinical Assistant Professor, Large Animal Medicine, Virginia- Maryland Regional College of Veterinary Medicine, Blacksburg, Virginia), says that during pregnancy most mares get vaccinated for Equine Herpes Virus 1 (EHV-1) which can cause abortion in mares. “Broodmares are generally vaccinated at 5, 7 and
9 months of pregnancy. EHV-1 typically causes abortion late term, in mares. This virus can also be latent in many horses, so the mare doesn’t have to be exposed to an outbreak of respiratory disease to get it and abort,” she says.
“The mare can either have a latent infection or be exposed to the disease or pick it up from aborted placentas or fetuses. Pregnant mares can easily be at risk for this disease, so we vaccinate them during pregnancy,” says Wilson.
“The other important thing regarding vaccina- tion for mares is to vaccinate them during the last 4 t t o o 6 6 w w e e e e k k s s o o f f p p r r e e g g n n a a n n c c y y w w i i t t h h c c o o r r e e v v a a c c c c i i n n e e s s ( (a a g g a a i i n n s s t t t t h h e e d d i i s s e e a a s s e e s s f f o o r r w w h h i i c c h h a a l l l l h h o o r r s s e e s s c c o o u u l l d d b b e e a a t t r r i i s s k k ) ). .
T T h h e e s s e e i i n n c c l lu u d d e e e e a a s s t t e e r r n n a a n n d d w w e e s s t t e e r r n n e e n n c c e e p p h h a a l l i it t i i s s , ,
A well vaccinated mare will pass on protection to the foal via the colostrum.
104 SPEEDHORSE, January 2017
EQUINE HEALTH