FROM:
MICK DOAK
RE:
GOAT NEWS
DATE:
13th March 2003
The
reason for the out breaks is most probably the low lying green patches
which along with the warm humid conditions we have experienced is the ideal
environment for Barber’s pole worms to breed in. Adult females can lay
up to 10,000 eggs per day for several months in ideal conditions, which
can give a massive contamination of pasture in a short time. Eggs are passed
from the host animal in their faeces and hatch to become infective larvae
after about 4 days. The larvae migrate up blades of moist grass and are
ingested by livestock.
After
ingestion the larvae grow to maturity in the fourth stomach and commence
egg laying in about 18 days reaching their height of production after 25
days. The adult worm is 1 to 2.5cm in length and easily seen in the fourth
stomach at post mortem. The male is reddish brown in colour while the female
has the distinctive red and white spirals similar to the red and white
poles once seen in every barber’s shop.
Ideal
conditions for the parasite build up include overcrowding, lush pasture
and warm humid conditions which can be experienced in most parts of the
state including the pastoral areas.
Months
which have average temperatures of 18 deg C and over and 50mm of rain are
the months when out breaks are more likely to occur. In wet summers the
disease may continue unchecked where as in drier years there may be a peak
incidence in early summer and another in autumn. Larvae picked up may become
retarded if conditions become less favorable and may continue their development
at a latter more suitable time as winter or spring. It has been found that
retarded larvae in pregnant animals will resume development as soon as
lactation begins.
Barber’s
pole worms are blood suckers and will leave their victims emaciated and
anaemic and in many cases also with a complicating disease such as enterotoxaemia
or pneumonia. As with many diseases the young, very old and stressed animals
are at the highest risk with effected ones first noticed at mustering time.
The effected animals lag behind, show rapid breathing as a result of anaemia,
may be staggery and often go down.
To
keep control of this silent killer you should take measures especially
if you have had problems in the past, as it seems to be more likely to
happen again and again on the same property. A strategic drenching program
along with rotation of paddocks will go along way to break the breeding
cycle. You should consult your local Wesfarmers merchandise specialist
who can give you the latest advise to control Barber’s pole worms and any
other disease you may have a problem with.
For
further details contact Mick Doak Mb 042439978 or AH Ph/Fax 08 93093225
or Email: doakmick@bigpond.com.au