By: Margaret Ross
Photo Credit: en.wikipedia.org
Adapted from: NCDA & CS Veterinary Division –
Animal Health Programs – Equine Infectious Anemia (EIA) & information from
Dr. Linnea Theisen, Eastern Equine Associates Mobile Veterinary Service
Have you
ever heard of Equine Infectious Anemia or EIA? According to an article from the
North Carolina Department of Agriculture and Consumer Services…
EIA is a
viral and infectious disease found in equids. It can accompany an illness that
may be acute, subacute or chronic and can also be subclinical in some cases.
EIA is a worldwide problem and has been reported in all of the mainland states.
The only known natural hosts of this disease are ponies, horses, mules and
donkeys. Typically, the outbreaks occur during late summer or early fall and
also overlap with the peak of biting insect populations. However, if EIA is
transmitted via a hypodermic needle, new infections can be produced at any time
during the year.
A
retrovirus is what causes EIA and it is related to the lentivirus that causes
AIDS in humans. At this time, it is thought that the equine virus does not
affect people. EIA has been found in milk, saliva, and blood of diseased horses
but typically loses its efficacy outside of the horse’s body. Boiling,
sunlight, and most chemical disinfectants destroy the virus. However, once a
horse has the virus, they carry it for life – regardless of how severe their
symptoms are.
The disease
is transmitted by intravenous, intramuscular, or subcutaneous injection of
blood contaminated with the disease. Insects that suck blood can also be a
source of infection transfer. The incubation period for the virus is around 14
days but could be much longer. Symptoms often include a high fever of 104 – 108
degrees F., lessened appetite, drastic loss of physical condition, severe
depression, incoordination, jaundice, increased heart rate, swelling of legs
and lower abdomen, and a yellowish or bloody discharge from the nose, along
with other symptoms.
Clinical
diagnosis is very difficult and needs to include regular observations of the
horse as well as recording body temperature twice daily. EIA should also be
distinguished from babesiosis, which is a blood disease that is transmitted
from ticks. It can be diagnosed by blood studies and is rare in North Carolina.
An antibody
test that is positive is thought to be the same as being infected, even if
symptoms do not concur with diagnosis. How severe the symptoms are depends on
the amount of virus in the blood at any particular time. Currently, a vaccine
is not available and there is no treatment or cure, other than supportive care. If your horse is showing signs of EIA,
isolate them until testing is complete. If the immunodiffusion test comes back
positive, immediate euthanasia must be considered. At this point, the state
veterinarian takes over and the horse must be either euthanized or isolated by
a certain number of miles from other horses. In addition, the horse must never
be moved from that property or change owners without getting approval from the
state veterinarian.
How can you be safe? You should only
buy horses known to be negative with the immunodiffusion test and require a
copy of those records. Be extremely careful with equipment that can transmit
blood from one horse to another. Fly / insect control, cleanliness, and careful
use of pesticides are all encouraged. If an EIA-positive horse must be kept,
that horse should be isolated from the others. Horse owners who have known
EIA-positive horses need to be aware of federal regulations when moving these
horses.
In addition, it is important to
note that you should always have proof of a current Coggins anytime you move
your horse from your property, even if you’re just going to trail ride. Barns
that board horses are also required to have current Coggins on all the horses.
Don’t purchase horses without a current negative Coggins test or transport
horses without one. If a horse owner brings a horse onto their farm without a
current Coggins, they should separate that horse (quarantine) until the test
results return. In order to get a health certificate, a current Coggins test is
required; health certificates are required for horses crossing state lines. If
you do not have a current Coggins and health certificate in this case, your
horses, truck, and trailer can all be confiscated!
Horse
owners can have their veterinarian submit a sample to test for EIA to the North
Carolina Department of Agriculture and Consumer Services. Visit
http://www.ncagr.gov/vet/FactSheets/equine.htm for more information and the
full article. If you would like more information on EIA, please contact your
veterinarian.
North Carolina State University and North
Carolina A&T State University commit themselves to positive action to
secure equal opportunity regardless of race, color, creed, national origin,
religion, sex, age, veteran status, or disability. In addition, the two Universities welcome all
persons without regard to sexual orientation.
North Carolina State University, North Carolina A&T State
University, U.S. Department of Agriculture, and local governments cooperating.
