Poisoning of a goat by Leucaena leucocephala
(Leg. Mimosoideae) in the State of Rio de Janeiro, Brazil, is
described. Fresh leaves of the plant were ingested as the animal’s
main meal for at least 4 months before it developed total
alopecia. At necropsy the thyroid was moderately enlarged.
Histological examination revealed a decrease in the number of
hair follicles (empty or in telogenic phase), vacuolation of
keratinocytes of the epidermis and hair follicles, and superficial
and follicular hyperkeratosis. Myxedema was found between
skeletal and cardiac muscles fibers, in the kidneys, and in the
submucosa/muscular layer of the digestive tract. The thyroid
follicles were enlarged and filled with copious amounts of
colloid (colloidal goiter). Although L. leucocephala is common
in several tropical regions, natural poisoning by this plant in
goats seems to be rare. It is the first report about spontaneous
poisoning in goats by L. leucocephala in Brazil