A34-Lancaster Farming, Saturday, October 14, 2000
live
Le
Chester
Extension
WHAT HORSE OWNERS
SHOULD KNOW ABOUT
WEST NILE VIRUS
On Sept. 26, the Pennsylvania
Department of Health reported
that two crows collected in Penn
sylvania were confirmed positive
for West Nile Virus (WNV) at
the National Veterinary Services
Laboratory (NVSL). These are
the first confirmed positive cases
of WNV in Pennsylvania.
One crow was collected in the
vicinity of Levitttown (Bucks
County) on Sept. 8 and the other
was collected in the vicinity of
Wayne (Chester County) on
Sept. 13.
Surveillance, especially in the
eastern and northern counties of
the commonwealth is ongoing.
What is West Nile encephali
tis?
West Nile encephalitis is a
brain infection caused by West
Nile Virus previously only found
in Africa, Eastern Europe, and
West Asia. Encephalitis is an in
flammation of the brain and can
be caused by head injury, bacteri
al infections, or most commonly,
viral infections.
How could a person get West
Nile encephalitis?
West Nile encephalitis cases
occur primarily in the late sum
mer or early fall. People can get
infected from the bite of certain
kinds of mosquitoes infected with
the virus. Mosquitoes get it when
they bite, or take a blood meal,
from birds infected with West
Nile Virus. Those mosquitoes
then transmit the virus to people
and other animals when biting to
take blood.
People over 50 years of age
have the highest risk of develop
ing severe illness because as we
age, our bodies have a harder
time fighting off disease. People
with comprised immune systems
are also at increased risk; how
ever, anyone can get the virus.
How could a horse get West
Nile Virus?
Horses become infected with
West Nile Virus after being bit
ten by an infected mosquito.
There is no evidence that horses
can transmit the West Nile Virus
to other horses, birds, or people.
What are the signs and symp
toms of West Nile encephalitis in
horses?
In horses that do become clini
cally ill, the virus infects the cen
tral nervous system and causes
symptoms of encephalitis. Clini
cal signs of encephalitis in horses
include loss of appetite and de
pression, in addition to any com
bination of the following signs:
• Fever
• Weakness of hind limbs
• Paralysis of hind limbs
• Impaired vision
• Ataxia
• Head pressing
• Aimless wandering
• Convulsions
• Inability to swallow
• Circling
• Hyperexcitability
• Coma.
It is important to note that not
all horses with clinical signs of
encephalitis have West Nile en
cephalitis. Other diseases, includ
ing rabies, botulism, equine
protozoal myeloencephalitis
and other mosquito-borne viral
encephalitic diseases of horses
caused by Eastern, Western, and
Venezuelan viruses can cause
a horse to have symptoms similar
to WNV. If you are concerned
your horse may be exhibiting
signs of encephalitis, please con
tact the Pennsylvania Depart
ment of Agriculture or your vet
erinarian. Only a blood test can
confirm the diagnosis of West
Nile encephalitis.
Is there treatment for West
Nile encephalitis in horses?
There is no specific treatment
for West Nile encephalitis in
horses. Supportive veterinary
care is recommended.
If my horse is vaccinated for
other diseases, will it be protect
ed from West Nile Virus?
No vaccine is available against
West Nile Virus. Horses vacci
nated against Eastern and West
ern and Venezuelan equine en
cephalitis are not protected
against West Nile Virus.
How can I prevent mosquitoes
from affecting my horses?
There are some easy steps you
can take to prevent mosquitoes
from affecting your horses. They
include;
• House horses indoors during
peak periods of mosquito activity
(dusk and dawn).
• Avoid turning on lights in
side the stable during the evening
and overnight. Mosquitoes are
attracted to incandescent bulbs
that glow yellow.
• Place incandescent bulbs
around the perimeter of the
stable to attract mosquitoes away
from the horses. Black lights
don’t attract mosquitoes well.
• Remove all birds, including
chickens, that are in or close to
the stable.
• Periodically look around the
property for dead birds, such as
crows. Any suspicious birds
should be reported to the Penn
sylvania Department of Health
at 1-877-PA-HEALTH. Use
gloves to handle dead birds and
place the birds in plastic bags.
• Eliminate areas of standing
water on your property. Shallow
standing water, used tires, ma
nure storage pits, and drainage
areas with stagnant water are
ideal mosquito breeding places.
• Topical preparations con
taining mosquito repellents are
available for horses. Read the
product label before using and
following all instructions.
• Fogging of stable premises
can be done in the evening to re
duce mosquitoes; read directions
carefully before using.
• For help in assessing mos
quito exposure risks on your
property and for suggested con
trol practices, please contact
your county extension office,
county department of health,
local veterinarian, or mosquito
and pest control company.
How can I reduce the number
of mosquitoes around my home
and neighborhood?
You can reduce the number of
mosquitoes around your home
and neighborhood by reducing
the amount of standing water
available for mosquito breeding.
Here are some simple steps you
can take:
• Dispose of tin cans, plastic
containers, ceramic pots, or simi
lar water-holding containers on
your property.
• Pay special attention to dis
carded tires. That’s where most
mosquitoes breed.
• Drill holes in the bottom of
recycling containers left out
doors. Containers with drainage
holes located on the sides collect
enough water for mosquitoes to
breed in.
• Clean clogged roof gutters
every year, particularly if the
leaves from surrounding trees
have a tendency to plug up the
drains. Millions of mosquitoes
can breed in roof gutters each
season.
• Turn over plastic wading
pools when not in use. A wading
pool becomes a place for mosqui
toes to breed.
• Turn over wheelbarrows
and don’t let water stagnate in
birdbaths. Both provide breeding
habitats for domestic mosquitoes.
• Aerate ornamental pools or
stock them with fish. Water gar
dens can become major mosquito
producers if they are allowed to
stagnate. Clean and chlorinate
swimming pools when not in use.
A swimming pool left untended
by a family on vacation for a
month can produce enough mos
quitoes to result in neighbor
hood-wide complaints. Mosqui
toes may even breed in the water
that collects on pool covers; and
• Use landscaping to elimi
nate standing water that collects
on your property. Mosquitoes
may breed in any puddle that
lasts for more than four days.
Can a horse with West Nile in
fect horses in neighboring stalls?
No. There Is no documented
evidence West Nile Virus is
transmitted from horse-to-horse.
However, if at all possible, horses
with suspected West Nile Virus
should be isolated from mosqui
toes and tested for the virus.
What are the symptoms of
West Nile Virus in people?
Mild infections are common
and include fever, headache, and
body aches, often with a skin
rash and swollen lymph glands.
Headache, high fever, neck stiff
ness, stupor, disorientation,
coma, tremors, occasional con
vulsions, paralysis, and death
mark more severe infection.
Is there treatment for people?
There is no specific treatment.
In more severe cases, hospitaliza
tion and intensive supportive
therapy may be needed.
Have people died from West
Nile encephalitis?
In New York City last sum
mer, seven of the 62 infected peo
ple died from the virus. All of the
people who died from the virus
were 75 or older. Historically,
about three to 15 percent of peo
ple with WNE have died, espe
cially seniors.
How does West Nile Virus ac
tually cause death in humans?
Following transmission by an
infected mosquito, West Nile
Virus multiplies in the person’s
Horse Pasture Workshop Oct. 18
BEDFORD (Bedford Co.)
Penn State Cooperative Exten
sion will be conducting a horse
pasture workshop in Perry
County Oct. 18 at the Lutheran
Parish Hall in New Bloomfield,
from 7 p.m.-9:30 p.m.
The purpose of the workshop
is to teach horse owners how to
improve the quality of pastures.
Topics covered at the workshop
will include managing soil fertili
ty, plant species selection, pas
ture renovation and weed man
agement, poisonous plants,
watering and fencing for pas
tures, and grazing management.
Speakers at the workshop in
clude Melanie Barkley, a county
extension agent and grazing spe
cialist from Bedford County,
Duane Pysher, grasslands ihan
agement specialist, Natural Re
blood and then crosses the blood
brain barrier to reach the brain.
The virus interferes with normal
central nervous system functions
and causes inflammation of the
brain.
Is there a vaccine for people?
There is no vaccine for West
Nile encephalitis.
What is Pennsylvania doing to
prevent a West Nile Virus out
break?
West Nile Virus has recently
been found in dead crows in
Pennsylvania. The crows were
submitted for testing from Bucks
and Chester counties. No posi
tive human or equine cases have
been found.
In response to this risk, several
state agencies, local governments
and health professionals have
launched a plan to find and con
trol the kind of mosquitoes
known to carry the virus. We are
testing animal populations that
may act as a host for the virus
and monitoring public health to
provide early warning if any peo
ple get infected.
Has the virus been found in
other states?
Yes, in 1999, laboratory-con
firmed West Nile Virus positive
birds were reported from the
Burlington, Hunterdon, Mercer,
and Warren counties in New Jer
sey, which are immediately adja
cent to Bucks, Delaware, North
amption, and Philadelphia
counties in Pennsylvania. A dead
crow found on Oct. 9, 1999 in
Burlington County, New Jersey,
was only five miles from Phila
delphia. Birds with the virus also
were found in Saratoga and Al
bany, N.Y. and Baltimore, Md.
in 1999.
New York City, New Jersey,
and Connecticut successfully
sprayed pesticides to kill infected
mosquitoes and to stop further
spread of the 1999 disease out
break. They trapped mosquitoes
and tested them for the virus
from homogenized pools of the
same mosquito species to de
termine if ongoing abatement ef
forts were effective.
In 2000, WNV has been found
in New York, New Jersey, Con
necticut, Rhode Island, Massa
chusetts, Maryland, Pennsyl
vania, and New Hampshire. Pos
itive horses have been found in
New York, New Jersey, Connect
icut, Rhode Island, and Massa
chusetts. The European Union
has implemented import restric
tions on horses coming from
these states.
Has the virus been found in
Pennsylvania?
Yes. Several infected crows
have recently been found in the
southeastern portion of Pennsyl
vania.
Can you get West Nile en
cephalitis from another person?
No. West Nile encephalitis is
not transmitted from person-to-
source Conservation Service
(NRCS), and Greg Strait, Fulton
County agent.
Dave Swartz, Perry County
extension agent, said, “The
workshop is a great way for
horse owners to learn how to in
crease the amount of grass pro
duced in their pastures. Horse
owners can then develop a diet
for their horses which includes
grass. We are privileged to have
a group of very knowledgeable
speakers for this workshop.”
For more information, contact
the Penn State Cooperative Ex
tension Office in Perry County at
(717) 582-5150. Cost for the
workshop is $lO. The fee in
cludes materials and refresh
ments.
person. You cannot get the virus
by touching or kissing a person
who has the disease, or from
contact with a health care work
er who has recently treated
someone with the disease.
What is the incubation peri
od?
The incubation period of a
West Nile Virus infection is
usually five to 15 days.
Do birds infected with the
virus die or become ill?
In the 1999 outbreak, large
numbers of North American
crows and other birds were ob
served becoming seriously ill and
dying.
What about ticks?
Some ticks in Europe and
Asia have been found to be in
fected with the virus. The U.S.
Centers for Disease Control and
Prevention also tested ticks in
the 1999 outbreak area. Infected
ticks cannot be killed by aerial
insecticide spraying, therefore in
fected ticks could prove to be a
carrier and transmitter of the
virus in the future.
Where can I get more inform
ation about West Nile Virus?
Citizens may visit http://
www.westnile.state.pa.us/ for fu
ture updates or call the Depart
ment of Health’s toll-free tele
phone number at
1-877-PA-HEALTH.
Care Of
Gestating Beef Cows
Beef cow/calf producers are
often guilty of feeding all cows in
one group through the winter
and I know how easy this makes
your chores. This, however, sim
ply cannot be the best practice
because cows of different ages
and condition need different
care.
If you consider that reproduc
tion is the most important thing
in a cow Jierd, yop will realize
the importance of separating
cows bred with their second calf
from the rest of the herd. In this
group you may also include old
cows or thin cows.
Cows bred with their second
calves, old cows, and thin cows
are usually the ones that have
the lowest reproduction rate. The
second calf cows are still grow
ing, and they get thin and don’t
cycle as early as the bulk of the
cow herd. In small herds, you
may even group your bred heif
ers with this elite group that we
have already organized; al
though, if possible, they should
be fed as a separate group.
Spring calving cows are now
entering the middle third of
pregnancy and nutritional needs
are increasing. For the main cow
herd you may use a ration con
sisting of 20-pounds of grass
hay/head/day of about eight per
cent protein along with a mineral
mix. This is enough to meet their
nutritional needs.
As for our elite group of old
cows, thin cows, bred heifers, and
2-year-olds, nutritional needs are
greater and the ration could con
sist of 16-pounds of grass hay/
head/day of about 11 percent
protein along with six-pounds of
shelled corn and mineral. If com
silage is available, feed
45-pounds per head per day
along with two-pounds of shelled
com and 1.5-pounds of 45 per
cent protein supplement. The
main cow herd could be fed
35-pounds of com silage/head/
day to meet their needs.
Sixty days prior to calving an
adjustment needs to be made in
rations for both groups to com
pensate for increasing energy
needs. Nutritionally balanced ra
tions are the most efficient and
usually the least costly. Be care
ful not to overfeed, underfeed, or
waste feed you cannot afford
to in today’s cattle economy.