176. Avian chlamydiosis (Zoon.).

Question 1

Occurence, aetiology epidemiology?

Answer 1

Chlamydiosis of Poultry

• Ornithosis
• Zoonotic!
• Susceptible: Turkey, Duck, geese, hen, pigeon, wild, caged (parrots)

Occurrence:

• widespread,
• asymptomatic common

Aetiology:

• C. psittaci
• 8 types (outer membrane proteins)
• Strains from birds: A-F
• Association between types and species

Epidemiology

• Virulence variants
• Shedding: faeces, nasal discharge
• Viral infections can complicate

Question 2

Pathogenesis?

Answer 2

Pathogenesis

• Infection: aerogenic(dust) replicate on mucous membranes : (Respiratory, alimentary) Blood
• Inflammation of mucous / serous membranes: respiratory, alimentary
• Encephalitis
• Shedding: faeces, nasal discharge - long, intermittent; stress and laying can increase shedding! increase

Question 3

Clinical signs?

Answer 3

Clinical signs

• Asymptomatic quite frequently
• Generalised
• Turkey, duck, goose: fever, pneumonia, sinusitis, conjunctivitis, CNS signs (geese), enteritis(yellow-green)
• Hen: milder - conjunctivitis, respiratory signs, diarrhoea
• Pigeon (exhausted after long flight)
• Mainly nestlings show clinical signs
• Pneumonia, upper respiratory infection, sinusitis, conjunctivitis, CNS signs
• Parrot: anorexia, conjunctivitis, dyspnoea, diarrhoea, weight loss, sudden death

Question 4

Pathology?

Answer 4

Pathology

• Pericarditis, perihepatitis,
• Pneumonia, Air sacs: serous ʹfibrinous inflammation
• Liver, spleen focal lesions, Enteritis

Question 5

Diagnosis?

Answer 5

Diagnosis

• Epidemiology ʹ clinical signs ʹ pathological lesions
• Detection of the agent: microscopy, PCR, isolation
• Detection of the antibodies (paired sera): CFT, ELISA

Question 6

Differential diagnosis?

Answer 6

Differential diagnosis

1. Salmonellosis,
2. fowl cholera,
3. erysipelas,
4. campylobacter,
5. borreliosis,
6. mycoplasmosis,
7. anatipestifer disease,
8. IB, ILT, TRT

Question 7

Treatment and prevention?

Answer 7

Treatment

• Tetracyclines, fluoroquinolones - long treatment
• Carriers, shedders remain

Prevention

• Hygiene, isolated keeping (wild birds)
• Keeping resistance high
• Imported cage birds: quarantine + antibiotic treatment
• No vaccines