Treatment of chickens, ducklings and turkey poults
with furazolidone (0.04% w/w, in the feed) for 10 days
inhibited monoamine oxidase (MAO) activities in the
alimentary tract, heart and brain. Only in the duckling
was an inhibition of MAO activity found in the liver.
In the chicken and duckling, furazolidone (200 mg/kg)
by crop tube inhibited MAO activities in the duodenal
mucosa, liver, heart and brain, whereas the same dose of
the drug given intramuscularly to the chicken was
ineffective. Furazolidone by crop tube was about
equipotent as an MAO inhibitor in chickens, ducklings and
turkey poults. Pretreatment of chickens and ducklings
with neomycin to suppress the alimentary microflora
reduced the effect of furazolidone on MAO activity,
suggesting that the microflora transformed the drug to
an active metabolite which subsequently inhibited MAO
activities in other organs
Furazolidone (0.04% w/w, 10 days) increased the
amount of 5-hydroxytryptamine (5-HT) in the brain of
chickens and ducklings, and potentiated the vasopressor
action of tyramine in chickens. The amounts of nor¬
adrenaline and adrenaline in the brain were unaffected
by the treatment, as were the actions of noradrenaline,
5-HT, histamine and tryptamine on blood pressure.
In poultry, furazolidone (0.04% w/W, 10 days)
produced an anorexia and an increase in the concentrat¬
ions of pyruvate and lactate in blood. The activation
of transketolase by thiamin pyrophosphate was greater in
haemolysates from furazolidone-treated chickens than in
control preparations. These observations suggested a
deficiency of thiamin in the furazolidone-treated birds.
However, intramuscular administration of thiamin HC1
(84 yg/kg, twice daily for 10 days) to the chicken did
not prevent the development of signs characteristic of
its deficiency.
In chickens given furazolidone (0.04% w/w, 10 days),
the weights of the adrenal and thyroid glands (as % of
body weight) and the oxygen consumption of hologenized
heart were all increased.
Furazolidone (0.04% w/w, 10 days) did not produce
an anaemia or affect the arterial blood pressure in the
conscious chickens, and the activities of plasma
aspartate transaminase and hepatic aminopyrine
demethylase were unaffected. Ducklings survived when
furazolidone was given in the feed at a concentration
of 0.04% w/w for 10 days, or by crop tube at a dose of
200 mg/kg.
