“…Two species of Chlamydia have principally been reported to infect sheep, C. 57 abortus which is a major cause of abortion in both sheep and goats, and C. pecorum, which 58 causes pneumonia, arthritis/polyarthritis, encephalomyelitis, conjunctivitis, enteritis, abortion 59 and metritis and infertility in domestic ruminants and pigs (Everett, techniques that would not have detected C. pecorum. Despite this, arthritis/polyarthritis due 78 to C. pecorum is known to occur in Australia, and has been reported from 13-month old rams 79 in Queensland (Tammemagi and Simmons, 1968) and from 3-6 month old lambs on the 80…”