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COLLECTION: GOAT HANDBOOK
ORIGIN: United States
DATE INCLUDED: June 1992
Extension Goat Handbook
This material was contributed from
collections at the National Agricultural Library.
However, users should direct all inquires about the
contents to authors or originating agencies.
DOCN 000000063
NO G-9
GRAIN OVERLOAD
J. L. Ayers; Los Olivos, CA
S. B. Guss; Pennsylvania State U., University Park
Health and Disease Management
1 This condition which is also called ''acute carbohydrate
engorgement'' or ''lactic acidosis'', is life threatening
and must be handled as an emergency. Treatment must
begin as soon as it is realized that the goat has
eaten a more than normal amount (as little as half
again as much) of grain or other sources of readily
fermentable starch. The longer treatment is delayed,
the more difficult it is to reverse the progressive
chain of events that will end in death in 2 to 4 days.
The underlying problem is the rapid fermentation of
starch in the rumen with the resultant production
of lactic acid. This acid is picked up by the blood
stream in dangerously high amounts that disrupt the
normal body chemistry.
2 Clinical Signs The severity of
the signs depends largely upon the amount eaten. In
the first few hours, a full rumen, restlessness and
crying in pain may be all that is seen. There are
mild forms which do not progress beyond simple indigestion.
However, in severe forms there may be evidence of
extreme pain (crying and getting up and down) which
will become intermittent and then be predominated
by depression. They will often stagger and even appear
blind. The appetite will disappear during the first
day as will rumen contractions. The fecus may become
soft.
3 The temperature will become sub-normal
unless the animal is exposed to hot sun. As the acidosis
(lactic acid level in the blood and body fluids) increases,
circulatory collapse (shock) will begin; this will
increase the heart rate. In cattle, animals with a
heart rate of less than 100 will much more likely
respond to treatment than one with a heart rate of
120-140. It seems likely that a similar prognostic
aid would be valid in goats. Respiratory rate becomes
fast and breathing is shallow. Diarrhea usually develops
and is profuse.
4 The excess lactic acid in the rumen
causes a large amount of body fluid to be transported
into the rumen. This is a dehydration process which
is detectable by an increase in the hematocrit (the
percentage of red blood cells in whole blood). This
decrease in the amount of fluid in the blood and the
acidosis cause circulatory collapse. The shock is
best detected clinically by a paling of the mucous
membranes, a fast heart but barely perceptible pulse.
As long as the hematocrit stays normal (30-40) the
prognosis (outlook) is favorable. A hematocrit above
45aids in the diagnosis of grain overload and indicates
a less favorable prognosis.
5 The rumen may feel full and doughy;
if less grain was consumed, it may feel resilient
because of increased fluid and gas. The rumen will
have no contractions but one may hear a lot of gas
rising through fluid.
6 Usually after two days the animal
will lie down and not voluntarily get up. They will
be extremely depressed.
7 Tissue Changes In animals dying
within two days; the cornified rumenal epithelium
is soft and easily removed; there is hemorrhage of
the underlying surface. There may be abomasitis and
enteritis. There is an odor suggestive of fermentation
and, if the necropsy is conducted within an hour of
death, the pH of rumen contents will be 4 to 5.
8 In cases lasting 2-3 days, the
rumen and reticulum walls may be greatly edematous
and hemorrhagic resulting in marked thickening.
9 Diagnosis When there is a known
exposure to grain, the signs may be easy to interpret.
When grain is offered to a group of animals, especially
for the first time, a predominant fast-eating bully
animal may be able to overfeed on the grain meant
for the other animals. However, if one does not expect
or can't find evidence of overload, the symptoms are
quite similar to any other acute septicemic disease
such as peracute mastitis or metritis or diffuse peritonitis.
Careful clinical examination by the veterinarian will
be very useful and the most revealing tool will be
the collection and finding of rumen fluid with a pH
of 4 to 4.8 and no protozoal activity.
10 Prevention Under most management
systems, grain overload in goats results from escape
of animals from their pens and finding an open or
otherwise unsecured source of grain. The first step
of prevention is having good pens. Even then escape
occasionally occurs; therefore the most important
step is to store grain inside a room or shed that
is absolutely goat-proof. To avoid human error, the
door should be self-closing and self-latching.
11 Treatment Because grain overload
is life threatening, your veterinarian should be consulted
immediately. Two different clinical possibilities
exist which require different courses of action. In
the first the animals are ''caught in the act'' or
you find them out of their pens with evidence that
they have eaten grain. They are not yet ill. The second
situation should be less common if the goats and facilities
are observed frequently. Here engorgement took place
12-48 hours previously and they now show signs of
lactic acidosis.
12 When the animals are found eating
illicit grain, call your veterinarian. In the event
a veterinarian is not immediately available the following
course of action is recommended.
13 First, remove all sources of feed
and water for 12-24 hours except good quality hay
equal to a one-half days ration per animal. Exercise
them 5-10 minutes every hour. The author prefers to
give 1 tablespoon (15cc) of Milk of Magnesia orally
followed by 1 ounce (30cc) of water (no more than
2 ounces) to an adult goat. This should be repeated
later if the animal starts to show signs of restlessness
or discomfort.
14 The second situation involves
animals that have engorged themselves 12-48 hours
previously and have progressively worsened. They may
be discovered this way or are worsening despite early
treatment. These goats should be isolated and observed
closely.
15 The color of the mucous membrane
of the eyes (or vulva or sheath of the penis) should
be observed early and regularly for evidence that
the healthy pink is changing to pale pink to white.
The heart rate can be counted by pulling a front leg
forward and placing ones ear over the chest where
the goat's elbow was. If the heart rate of the resting,
unexcited goat is as high as 90-100 beats per minute
range, they must be watched closely.
16 If the mucous membranes are becoming
pale and the heart rate is above 100-110, if the animal
is becoming depressed or if it staggers slightly or
is showing evidence of pain, the veterinarian should
personally evaluate and treat the animals.
17 In moderate cases drenching or
dosing 50 grams of magnesium hydroxide or magnesium
oxide in a liter of warm water to a 70 kg (155 pound)
goat, followed by kneading the rumen to obtain mixing
may be sufficient treatment. In more severe cases
that are still standing and the rumen pH is 5 to 6,
a large stomach tube may be passed and the rumen washed
with 10-15 irrigations. Tepid water is pumped in until
obvious rumen distension occurs; then the rumen is
allowed to empty by gravity flow. It is not enough
to retrieve the water pumped in; grain must be washed
out.
18 Systemic acidosis is combated
with oral or intravenous fluid administration. Five
percent sodium bicarbonate is given intravenously
for severe acidosis at the rate of 500 ml per 100
lbs of body weight over a period of 30 minutes. This
is followed by 1.3 odium bicarbonate at the rate of
65 ml per lb of body weight over the next 6-12 hours.
19 In severe cases, where the animal
is down, in shock (as judged by pale mucous membranes
and a heart rate of 120-140 or faster), severely depressed
and rumen pH below 5, the only life saving procedure
may be surgical removal of the grain from the rumen
by rumenotomy. This is a high risk procedure because
of the already extremely bad condition of the animal.
In cases that progress this far, there is also a rather
high possibility of severe fungal rumenitis developing
in 3 to 5 days. The owner should realize that surgery
is much more apt to be successful earlier in the course
of the disease at a time when conservative treatment
still has a chance to work. The owner, with the advice
of the veterinarian must decide the degree of acceptable
risk.
20 Goats that respond favorably to
rumen washings or rumenotomy and fluid therapy will
show greater muscle strength and urinate within one
hour and attempt to stand in 6-12 hours.
21 All goats that have not been vaccinated
for Cl perfringens type C and type D must be given
the antitoxin because of the greatly increased risk
of enterotoxemia under these conditions.
GRAIN OVERLOAD
COLLECTION;GOAT HANDBOOK
ORIGIN;United States
DATE_INCLUDED;June 1992
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