(This
report was written in 1995. We have had great success with the CAE
prevention program.)
Caprine Arthritis Encephalitis
Rachael Herrell
KASH
Grade 8
Abstract
This report is trying to inform one about Caprine Arthritis Encephalitis Virus (CAEV) and what the effects on the goat might possibly be. This report is also going to try to inform one how this crippling disease can be prevented through careful herd management and annual herd testing.
Problem
Many
of the goats in the United States have CAE (65-81%) and the disease is very hard
to get rid of in the herd, and I believe I have infected animals in my herd.
Hypothesis
I believe that part of my herd will have the CAE virus.
Caprine Arthritis
Encephalitis
Caprine Arthritis Encephalitis virus is a type of arthritis that only goats can acquire. Some of the symptoms of this disease are debilitating arthritis, severe weight loss, massive swelling in the joints, and chronic udder fibrosis (hard udder) accompanied by decreased milk production, which might lead the owner to economic loss of premature culling in goat herds. Why this is such a big concern is because between 65-81% of the goats in the United States test seropositive for CAEV. “Caprine Arthritis –Encephalitis virus (CAEV) is an epidemic in most dairies in the United States,” quoted by Crawford and Adams (East et al., 1992).
Most
researchers have found that the disease is primarily transferred through the
colostrum or milk produced by infected dams.
Adams ,one such expert, quoted , “The virus is thought to be
transmitted mainly through the ingestion of infectious colostrum or milk”
(East et al., 1992). To prevent the
spread by the milk is to have seregant mothers or to feed the kids pasteurized
milk and heat treated colostrum. The seregant mothers are mainly used in a herd that has a
numerous amount of animals. This
method is very affective, but if the mother happens to become positive in the
course of her lactation then the kids are positive.
Another way to prevent the goat’s transmission of this disease is to
separate the babies immediately after birth, then the herdsman can raise the
kids on heat treated goat colostrum and pasteurized goat milk, cow colostrum or
milk, and/or commercial milk replacers. How
the caretaker would heat-treat colostrum is, “one would heat the colostrum to
133-138 degrees F and held at that temperature for one hour to inactivate the
virus.” quoted by Nancy K. Snider at Washington Animal Disease Diag. Lab (Schalle
and Everman, 1996). Then the herd
manager might return the kids into the CAE negative herd between weaning and
their first lactation.
A
doe that is CAE negative and is introduced to a positive herd can get CAE within
5 years by exchanging saliva and eating fecal from other goats.
A doe, raised on a CAE prevention program, in the experimental herd was
given raw milk to get her to gain weight and the milk that she drank was
infected. When this doe was checked
she did have CAE after being fed the raw milk.
A way to prevent CAE is by separating the two herds with one or two
fences and pasteurizing all milk before consumption.
When it is time to milk, the herdsman might milk the negative does first
because CAE can be transmitted through milk, which could possibly on the milking
equipment.
There
is a third way of transmission is the method of tattooing.
Since the tattoo pins have to penetrate the skin to get the ink to be
permanent, the CAE virus gets onto the tattooing pins and is transferred from
one goat to the next. The way of
prevention is to tattoo the does that are negative first then the does that are
positive. Sterilizing between goats
by rubbing alcohol on the pins to make sure all of the blood is off of the pins
or needles between each goat.
When
the herdsman has done all of the steps for prevention he/she will want to have
his/her animals tested annually to see if he/she went wrong anywhere.
There are two main types of tests, which are the kinetic enzyme link
immunosorbant assay (ELISA), and the agar gel immunodiffusion (AGID). The ELISA test has a sensitivity level of 95.2% while the
AGID test is 56.1% sensitive in the studies done.
Although the care taker can have kids tested under six months of age, the
accuracy on both tests will greatly decrease, because of false positives on kids
fed pastuerized milk from positive CAE does. However if the owner wishes to have his/her kids tested at an
age less than six months and the test comes back positive, Washington State
University will retest more serum from the same goat for free at this time.
The
method to take blood from an animal for CAE testing is in the following order.
First, the blood collector should get the goat in a restraint manner.
The second thing one would do is to get a cotton ball with alcohol to rub
the area to clean it of dirt. One
would need about a six cc syringes to draw the blood from cleaned area of the
animal. Usually the blood would be
drawn from the neck of the goat, by blocking off the blood vein with the thumb
and middle finger, then locate the vein above the blockage. Then the collector inserts the needle into the vein and
slowly pulls back on the plunger. If
the correct place was located then blood will begin flowing into the syringe.
After approximately 2cc of blood has been collected, one removes the
needle. Immediately after removing
the needle someone should put the blood in the red clot tube, while another
person should block off the puncture with his index finger and middle finger.
The red blood clot tube should have that goat’s registration number to
identify the blood sample. The
collector should fill out the information on the packet which will be sent to
the lab which will be testing the goats. The
information filled out correctly will insure that the serum will not be mixed up
with other blood. If the goat that
is being tested is not registered, it’s name and tattoo or birth date can be
used for identification. One should
always have extra supplies syringes, needles and red clot tubes on hand in case
of an accident. The experimental
herd’s samples were drawn on Feb. 11, 1997.
Three
of the does in the herd were raised on a CAE prevention program.
Two of those does after being introduced into the experimental herd were
fed raw milk which probably was infected with the CAE virus.
Both of those does came back positive with the virus, whereas the doe
which was not fed the raw milk came back negative CAE.
The other goats in the herd were not on a CAE prevention program and
there were no records on their dams pertaining to CAE.
My control herd in this project is all the herds tested in Adams research. The experimental herd is my herd (the herd that is being tested for the first time). The control herd’s average is from 65%-81% which tested positive for the CAE virus. My herd, the experimental herd, ended up testing exactly 77.7% positive which is in the range of the average goat herd in America according to Adams research, which proved my hypothesis to be correct. Through culling, CAE prevention, and replacing with negative animals, my herd is now projected at 84.3% CAE negative.
Conclusion
The samples were sent to Washington Animal Diagnostic Laboratory on Feb. 12, 1997 by overnight mail. They performed an ELISA test on the samples. The results were taken by phone on Feb. 17, 1997. The results showed that 77.7% (refer to chart 1) of my herd was infected with this virus. This proved my hypothesis to be correct. Now proper precautions are being taken to prevent the spread of this disease in the experimental herd.
Scripture Verse
Isaiah 40:11 He shall feed his flock like a shepherd :he shall gather the lambs with his arm, and carry them in his bosom, and shall gently lead those that are with young. Isaiah 40:11 (KJV)
This
verse means to me that the Lord cares for each and every person as an individual
just like I care for each goat as an individual and no one goat is more
important than the other. The good shepherd does not ignore the problems , sicknesses,
or concerns of the individual person. I
do not neglect the individuals in my herd because they are sick, but I care for
them and try to comfort them to the best of my ability.
When I found out that they had CAE, I decided to practice prevention and
to face my problem head on instead of ignoring the situation.
I do not ignore one because it is of lesser quality or I do not feel like
taking care of it. It is my desire
to give every animal the chance to live up to it’s full potential.
Reference
East, N. E., Rowe, J. D., Dahlberg, J. E.,
Theilen, G. H., & Pedersen, N. C (1993).
Modes
of transmission of caprine arthritis-encephalitis virus infection. Small Ruminant Research, p.251-262.
Hawkins, David DVM (1996, June).
Tattooing can spread CAE. United
Caprine News,
p.
27
Schalle, J. V., & Everman, J. (1996, January). Questions most often asked about CAE….
United
Caprine News, p.22-23.
Chart 1
1997
Animal ID Result
Mattie
Positive
Nannette
Negative
Star
Positive
Excaliber
Positive
Summer
Positive
Wendy
Positive
Dracena
Negative
Millie
Positive
Easter
Positive
seven
animals were Positive
two
animals were negative
1998
Animal ID
Result
Mattie
Culled
·
Mercury
Negative
·
Maximillion
Negative
·
Miracle
Negative
Nannette
Negative
·
Natasha
Negative
Star
Culled
·
Sonata
Negative
Excaliber
Positive
Summer
Positive
Wendy
Culled
Dracena
Positive
·
Dutchess
Negative
Millie
Culled
·
Megan
Negative
·
Melody
Sold
Easter
Culled did not breed replaced by number 10
Brandy
Positive
Shelly
Negative
Deeann
Negative
Reflection
Negative
Cruise
Negative
six animals were culled or sold
twelve animals are Negative
four animals are Positive
Meanings
Negative-
No antibody detected.
Positive- Antibody present indicating infection of passive transfer.
· represents kids out of the previous dam
