175. Chlamydial diseases of sheep (Zoon.).

Question 1

Chlamydiosis of sheep and goats Occurence and aetiology?

Answer 1

Chlamydiosis of sheep & goats (enzootic abortion of ewes, EAE) – important disease!

Occurrence

• Widespread, frequent
• Australia, New-Zealand (C. abortus is not present)
• Most frequent infectious abortion

Aetiology

• C. abortus: abortion
• C. pecorum: arthritis, conjunctivitis, enteritis, pneumonia
• Sometimes C. psittaci

Question 2

Epidemiology and pathogenesis?

Answer 2

Epidemiology

• Long presence in the flock
• Abortion: after introduction of young pregnant sheep (high amount of bacteria shed with aborted foetal
• fluids – can contaminate feed/water)
• Respiratory disease: in few-week-old lambs, predisposing factors

Pathogenesis

• PO/aerogenic infection→ intestinal epithelium → organs
• Uterus, foetus: inflammation of the trophoblast cells, thrombotic vasculitis, necrosis
• Lungs, conjunctiva: bacterial infections can complicate
• Joints
• Shed in faeces, aborted foetus
• Pregnant ewes abort or non-viable lambs will be born

Question 3

Clinical signs?

Answer 3

Question 4

Diagnosis, treatment and prevention?

Answer 4

Diagnosis

• Epidemiology – clinical signs – post mortem lesions
• Detection of the bacterium: microscopy, isolation, IF, PCR
• Detection of antibodies: CFT, ELISA

Treatment

• Diseased, pregnant
• Tetracycline treatment 3-5 days
• Isolation of aborted sheep
• Disinfection

Prevention

• No mixing
• Inactivated vaccine
• Young ewes: 2x, older 1x
• Rams have to be vaccinated, too
• Vaccination of newly introduced animals! (also quarantine)
• Shedding is not prevented
• Live, attenuated vaccine: heat sensitive mutant, can cause abortion (not safe)