Viral arthritis (tenosynovitis)
From Poultry Hub
Viral arthritis also known as tenosynovitis is a classic manifestation of reovirus infection of chickens wit at least 5 sero-types of the virus occur. Morbidity is high but mortality is usually low.
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Transmission
Transmission is by faecal contamination. Birds can remain carriers for over 250 days. The virus is resistant to heat, ether, chloroform, pH and environmental factors. Reoviruses vary distinctively in pathogenicity and the tissue damaged. Some can cause other disease syndromes such as early chick mortality and malabsorption syndrome. Some strains have shown severe systemic disease including pericarditis in chickens. Others have caused immunosuppression by damaging the cloacal bursa in ducks.
Symptoms
- Lameness.
- Low mobility.
- Poor growth.
- Inflammation at hock.
- Swelling of tendon sheaths.
- Unthriftiness.
- Rupture of gastrocnemius tendons.
Diagnosis
Diagnosis may be based on the history, lesions, IFA and rising antibody titre. Isolation may be readily achieved in CE yolk sac and CAM and also cell cultures (CE kidney or liver cells). Serology may be by DID, FAT or Elisa. 'Silent' infections (not associated with obvious disease) are common. Differentiate from mycoplasmosis, salmonellosis, Marek's, Pasteurella, erysipelas.
Prevention
Vaccination is ideally carried out by administering a live vaccine in rear followed by an inactivated vaccine prior to coming into lay. Most vaccines are based on strain 11/33. Rear birds in all-in/all-out production systems.
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