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Urinary
Calculi
by
Jennifer
Maas,
DVM
This
year
I’ve
seen
several
cases
of
urinary
obstruction
in
male
sheep
and
goats.
A
four-month-old
Nubian
wether
underwent
successful
surgery,
one
ram
lamb
was
put
to
sleep
because
his
urethra
had
ruptured,
one
mature
breeding
ram
was
put
to
sleep
because
of
suspected
urethral
rupture
and
one
yearling
ram’s
urethral
process
was
snipped
to
free
the
obstruction.
A
four-month-old
Pygmy
wether
who
was
unblocked
by
snipping
the
urethral
process
went
on
to
block
higher
up
in
the
urethra,
thus
necessitating
a
urethrostomy.
Almost
any
time
a
client
calls
concerning
a
male
sheep
or
goat
with
the
complaint,
“My
animal
is
depressed,
won’t
eat,
looks
bloated,
acts
constipated,
and
is
straining,”
my
thoughts
jump
to
a
blockage
of
the
urethra,
the
tube
leading
from
the
bladder
to
the
penis
which
passes
sperm
and
urine,
with
urethral
“calculi”,
small
stones
from
the
bladder
which
lodge
in
the
long,
thin
male
urethra.
Usually,
when
I
arrive,
the
animal
is
down,
had
abnormally
dry
hair
around
the
penis,
and
is
lying
in
an
unusually
dry
stall.
Because
of
the
buildup
of
urea
and
other
toxins
that
are
normally
passed
in
the
urine,
the
animal
is
quite
depressed.
A
combination
of
decreased
water
intake
and
increased
blood
toxin
level
causes
the
animal
to
also
be
dehydrated.
If
the
animal
is
not
castrated,
I
can
extrude
the
penis
and
check
the
small,
worm-like
urethral
process
at
the
end
of
the
penis
for
buildup
of
the
small
stones.
This
is
a
common
site
of
obstruction
since
it
is
quite
small.
In
the
castrated
animal,
especially
in
one
castrated
at
a
young
age,
the
attachments
of
the
penis
to
the
prepuce
have
not
yet
broken
down
and
sometimes
it
is
impossible
to
examine
or
extrude
the
end
of
the
penis.
If
there
are
crystals
in
the
urethral
process,
easily
seen
and
felt
on
the
exam,
I
can
snip
off
the
end
of
the
process
with
a
sharp
pair
of
scissors,
thus
often
ridding
the
animal
of
the
blockage.
This
must
often
be
done
under
light
anesthesia,
especially
when
dealing
with
goats.
Obtaining
a
good
stream
of
urine
is
surely
a
relief
once
the
urethral
process
is
snipped,
but
the
animal
may
very
possibly
become
reblocked
with
stones
higher
up,
even
if
this
is
achieved.
If
the
urethral
process
cannot
be
visualized
and/or
the
blockage
doesn’t
occur
at
this
point,
then
either
surgery
or
euthanasia
should
be
considered.
If
surgery
is
the
decision,
it
should
be
performed
promptly,
before
the
animal
becomes
more
toxic.
I
must
convince
myself
the
problem
is
a
urethral
obstruction.
This
can
sometimes
be
done
by
feeling
a
large
abnormally
hard
bladder.
If
the
bladder
can’t
be
felt
and
obstruction
is
suspected,
a
ruptured
bladder
should
be
ruled
out
by
tapping
the
abdomen
with
a
hypodermic
needle
and
checking
for
urine
spillage
into
the
abdominal
cavity.
A
high
blood
urea
and
blood
creatinine
can
also
tell
me,
especially
in
the
case
of
a
large
animal
whose
bladder
is
difficult
to
feel,
whether
I
am
dealing
with
a
probable
urinary
obstruction.
The
other
common
site
of
blockage
is
a
point
at
which
the
urethra
make
an
S-shaped
curve,
the
sigmoid
flexure.
The
sigmoid
flexure
frustrates
all
attempts
at
passing
a
catheter
from
the
penis
to
the
bladder
because
of
it’s
curvature.
If
the
blockage
occurs
at
this
point,
the
only
solution
is
to
do
a
urethrostomy.
This
involves
making
a
longitudinal
incision
over
the
urethra
at
a
site
below
the
anus,
suturing
the
opened
incision
to
the
skin
and
allowing
it
to
heal
open,
thus
causing
a
permanent
hole
in
the
urethra
where
urine
crystals
can
pass
freely.
Surgery
is
done
under
general
anesthesia
and
is
fraught
with
complications
after
the
surgery,
mainly
consisting
of
the
urethra
scarring
shut
or
stricturing
at
the
surgical
site.
The
success
rate
is
probably
about
50%.
This
surgery
is
useful
only
to
save
the
animal’s
life,
but
not
to
salvage
it
as
a
breeding
individual.
Causes
and
Prevention:
Urolithiasis
or
calculosis,
the
metabolic
disease
of
male
sheep
and
goats,
is
the
blockage
of
the
urethra
by
struvite
crystals,
preventing
the
normal
passage
of
urine
from
the
bladder.
The
disease,
caused
by
what
appears
to
be
a
complex
of
dietary
and
environmental
factors,
begins
with
the
formation
of
ammonium
phosphate
ions
which
form
a
nidus
to
which
other
ions
and
eventually
cells
and
mucus
from
the
bladder
adhere,
forming
a
calculus
of
up
to
3
mm
in
diameter.
These
calculi
pass
without
problem
through
the
large,
short
female
urethra,
but
rub
and
irritate
the
lining
of
the
long,
thin
male
urethra,
causing
irritation,
swelling
and
eventual
obstruction
and
occlusion
of
urine
outflow.
Males
from
a
few
weeks
of
age
to
mature
rams
and
bucks
are
all
susceptible
to
this
noncontiguous
disease,
but
the
highest
risk
population
is
the
wether
3-6
months
old
on
a
high
concentrate
diet
who
has
been
castrated
at
an
early
age.
Factors
which
appear
to
predispose
to
the
formation
of
urinary
calculi:
-
A
high
percentage
of
concentrates
(grain)
in
the
diet.
-
A
high
phosphorus
to
calcium
ratio.
-
Castration
at
an
early
age
(1-4
weeks),
slowing
growth
and
development,
resulting
in
a
juvenile
penis
and
urethra
(narrower
lumen
and
persistent
adhesions
of
the
penis
to
the
prepuce)
-
Water
deprivation.
-
Inclement
wether:
Prevention
of
this
deadly
metabolic
disease
involves:
-
Castration
after
the
animal
is
a
month
old.
-
Feeding
a
2:1
calcium/phosphorus
ratio
rather
than
offering
minerals
free
choice.
-
Adding
sodium
chloride
to
the
diet
so
that
it
constitutes
4%
of
the
dry
matter
in
the
diet.
This
will
aid
by
discouraging
the
formation
of
crystals
through
its
ionic
action,
and
by
increasing
the
animal’s
water
intake.
-
Offering
the
animal
plenty
of
warm,
fresh
water.
Finally,
it
is
extremely
important
to
avoid
over-feeding
your
male
goats.
Castrated
or
not,
a
male
goat
does
not
need
anywhere
near
the
concentrate
required
by
a
milk
producing
doe.
Although
a
young
animal
needs
concentrate,
care
should
be
taken
not
to
over-feed
the
young
male.
As
long
as
good
quality
hay
is
fed,
concentrate
should
figure
only
marginally
in
the
diet
of
the
mature
animal.
Excerpts
from:
Kinne,
Maxine,
ed.
Pygmy
Goats:
Best
of
Memo
2
(1982-1987)
National
Pygmy
Goat
Association:
pp
147-148
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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