
studies on eperythrozoon infection in sheep
the intravenous inoculation of blood from sheep in the parasi-
taemic stage of eperythrozoon infection produced detectable
parasitaemia in recipient sheep within 7 days.  the parasitaemia
lasted from 3 to 12 weeks and was accompanied by anaemia and
occasionally by icterus.  no other symptoms developed and in a
controlled experiment on hoggs there was no significant difference
in weight gain between infected and control animals.
a concurrent attack of tick-borne fever led to the disappearance
of eperythrozoon from the circulating blood.  it is suggested that this
phenomenon may be caused by the pyrexia.
the incubation period following the inoculation of infected blood
in ten 3 to 4 week old lambs varied from 3 to 6 weeks.  in eight of
these animals the symptoms were less severe than in adult sheep, but
the two smallest lambs developed a profound anaemia and failed to
gain weight.
culture of the organism on sheep blood agar or on sheep kidney
monolayers was unsuccessful as was the attempted transmission of
the infection to mice.
the transference of keds and lice from infected to uninfected
sheep failed to transmit the infection, but a sheep was infected by the
intravenous inoculation of ground-up lice from an infected animal.
the only characteristic histopathological changes in infected
sheep were lymphoid hyperplasia of the malphigian corpuscles in the
spleen and deposition of haemosiderin in the cells of the proximal
convoluted tubules in the kidney cortex.
