The progeny of two emu breeder pairs, which had a history of producing offspring with
gangliosidosis, were monitored for 15 mo. DNA fingerprinting revealed that individuals in each breeder pair were not related to each other. One breeder pair had 13 progeny that reached or exceeded the age of 1 mo, and six of these progeny developed
gangliosidosis. The mean age at which these affected emus were euthanatized, with distinct neurologic disease, or died was 5.7 mo. The second emu pair had 13 progeny, seven of which developed
gangliosidosis, with a mean age of
euthanasia/death of 4.6 mo. Affected emus died or were euthanatized from 2 to 8 mo of age. The primary clinical sign in the affected emus was mild to severe
ataxia. Severe
hemorrhage into the body cavity or the muscles of the thigh was noted in 8 of 13 of the affected emus. Brain
ganglioside levels were evaluated in six of the affected emus and six controls. Significant increases (P < 0.05) in
gangliosides GM1 and GM3 were noted, with 2.3- and 4.9-fold increases in these two
gangliosides, respectively, in affected emus. Furthermore, the diseased emu brains contained
ganglioside GM2, whereas this monosialoganglioside was undetectable in the brains of normal controls. Total mean brain
ganglioside sialic acid in affected emus was increased 3.3-fold in comparison with controls. Serum chemistries revealed
elevated cholesterol and decreased
uric acid levels in affected emus.
Gangliosidosis in emus is an inherited disease process that, in the current study, caused 50% mortality in the progeny of two emu breeder pairs. The elimination of this lethal gene from emu breeder stock is essential for the long-term economic viability of the United States emu industry.