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Coccidiosis:
Understanding
the
Drugs
Available
for
Control
by
N.
Galen
Walters,
DVM
Most
Pygmy
goat
owners
are
aware
that
coccidiosis
is
a
lurking
condition
always
awaiting
the
opportunity
to
become
a
full-blown
disease
in
their
herds.
Many
understand
that
“treatment”
is
a
matter
of
controlling
rather
than
eradicating
the
condition,
but
few
realize
that
several
treatment
choices
are
available,
each
appropriate
to
specific
stages
in
the
life
cycle
of
the
organism.
This
becomes
useful
information
when
owners
are
faced
with
attempting
to
treat
an
outbreak
of
disease
or
trying
to
prevent
one.
The
following
schematic
life
cycle
of
coccidia
will
help
clarify
where
the
various
drugs
available
for
treatment
have
their
effect.
STEPS
OF
DEVELOPMENT
OF
COCCIDIA
-
1
-
Oocyst
(egg)
contaminates
the
environment
via
feces
from
an
infected
animal.
-
2
-
After
the
oocyst
matures
in
the
soil
(1-7
days)
to
become
an
infective
sporocyst
stage,
a
susceptible
Pygmy
ingests
it.
-
3
-
Sporocyst
bursts
open
inside
the
internal
lumen
and
releases
sporozoites.
-
4
-
Sporozoites
enter
internal
cells
and
multiply,
producing
thousands
of
merozoites.
-
5
-
Merozoites
rupture
from
intestinal
cell
walls
and
enter
more
intestinal
cells.
-
6
-
Merozoites
unite
to
eventually
form
an
oocyst
which
will
be
released
from
the
intestinal
cell
wall
and
be
passed
out
via
feces.
-
7
-
Oocysts
rupturing
from
intestinal
wall
and
passed
via
the
feces.
The
three
most
commonly
available
drugs
(coccidiostats)
for
use
in
goats
are
Sulfa
drugs,
Amprolium
(Corid®),
and
Decoquinate
(Deccox®).
Sulfa
drugs
are
the
only
drugs
actually
labeled
for
use
in
goats.
IMPORTANT
POINTS
TO
KEEP
IN
MIND
-
All
drugs
available
are
only
effective
in
reducing
numbers
produced;
they
do
not
directly
kill
the
organism.
-
Clinical
disease
occurs
as
a
direct
result
of
intestinal
cell
wall
damage
and
most
during
the
merozoite
stage,
14-20
days
after
initial
ingestion.
-
Goats
have
the
ability
to
develop
an
active
immunity
against
coccidia
which
generally
requires
ten
days
to
develop.
Medication
helps
slow
down
the
organisms’
multiplication
long
enough
for
the
animal
to
develop
this
immunity.
-
Immunity
may
be
overridden
by
massive
exposure
to
oocysts.
-
Epidemics
occur
when:
-
Resistance
is
decreased
due
to
stress
(feed
changes,
crowding)
-
There
is
an
increased
exposure
to
oocysts,
massive
contamination,
poor
cleanliness,
accumulation
of
feces,
crowding.
-
Susceptible
(young)
animal
is
introduced
to
a
contaminated
area
–
too
young
to
have
developed
an
immunity.
-
Coccidiosis
is
a
self-limiting
infection
provided
the
animal
is
not
reinfected,
i.e.,
once
the
organism
completes
its
life
cycle,
it
is
shed.
-
Control
of
the
infective
cycle
is
the
key
in
prevention
(oocysts
in
feces
and
in
environment
for
greater
than
7
days).
-
Environmental
factors
in
control:
-
Complete
dryness
or
exposure
to
direct
sunlight
is
lethal
to
oocysts.
-
Infection
stage
takes
1-7
days
to
develop
from
time
oocysts
pass
in
feces.
-
Optimum
temperature
for
the
development
of
oocysts
is
68-73°F.
Few
develop
below
32-40°F,
but
oocysts
can
survive
for
up
to
8
months
as
low
as
6°F.
SULFA
DRUGS
-
Mode
of
action:
Reduces
numbers
of
organisms
at
the
end
of
the
life
cycle,
steps
5-6,
the
merozoite
stage.
-
Effective
time
to
use:
When
you
actually
see
clinical
outbreaks
of
disease.
-
Disadvantages:
Because
effect
is
late
in
the
cycle,
intestinal
damage
may
already
be
extensive.
Can
be
toxic
at
wrong
dosage.
-
Advantages:
Helps
prevent
secondary
bacterial
infections.
-
Treatment:
Sulfamethazine
(poultry
prep)
added
to
water
or
milk
at
60
mg/lb
per
day.
Treat
kids
at
3-4
weeks
of
age
for
7
days
and
repeat
in
3
weeks.
May
have
to
treat
at
21-day
cycles
through
3
weeks
post-weaning.
AMPROLIUM
(Corid®)
-
Mode
of
action:
Acts
early
in
the
life
cycle,
steps
4-5.
-
Effective
time
to
use:
The
choice
to
use
when
you
are
already
in
a
known
contaminated
area
and/or
just
beginning
to
see
clinical
disease.
-
Disadvantages:
Interferes
with
thiamine
utilization
in
the
coccidia
organism,
hence
retards
their
growth
and
multiplication.
Thought
to
make
the
host
thiamine
deficient
as
well.
May
need
to
supplement
with
thiamine.
-
Treatment:
Have
to
start
kids
at
2
weeks
old.
25-30
mg/lb
for
10
days
or
15-30
mg/lb
for
21
days.
Repeat
in
3
weeks.
DECOQUINATE
(Deccox®)
-
Mode
of
action:
Effective
in
reducing
numbers
very
early
in
the
life
cycle,
steps
3-5,
the
sporozoite
stage.
-
Effective
time
to
use:
Best
used
any
time
you
move
susceptible
animals
into
an
infected
area.
First
day
they
enter
then
area,
put
in
the
ration.
-
Advantages:
Works
well
as
a
preventative
and
treatment
before
marked
intestinal
wall
destruction
takes
place.
-
Treatment:
Start
at
2
weeks
old
and
use
for
28
continuous
days.
¼
mg/lb.
In
older
kids
and
adults,
offer
free
choice
in
granulated
salt,
mixed
at
the
rate
of
2
lbs.
of
6%
Deccox
premix
in
50
lbs.
of
salt.
Excerpts
from:
Kinne,
Maxine,
ed.
Pygmy
Goats:
Best
of
Memo
2
(1982-1987)
National
Pygmy
Goat
Association:
pp
118-119
This
document
is
for
informational
purposes
only
and
is
in
no
way
intended
to
be
a
substitute
for
medical
consultation
with
a
qualified
veterinary
professional.
The
information
provided
through
this
document
is
not
meant
to
be
used
in
the
diagnosis
or
treatment
of
a
health
problem
or
disease,
nor
should
it
be
construed
as
such.
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