Veterinary Services

Multifocal pin-point liver necrosis was found in five out of six layers aged 28 weeks submitted from a free-range flock with a history of weight loss, reduced production and sudden deaths. The birds were in poor to average condition, with feed in the crops and gizzards. Small numbers of red mites were present, but no evidence was found of worm or coccidial burdens and no significant bacteria were isolated. Histopathology revealed foci of fibrinoid necrosis and microthrombosis in the liver, but no bacteria were seen within the lesions. A similar condition, sometimes referred to as "spotty liver syndrome", was not uncommon in free-range flocks in the 1980s, and Crawshaw and Young (Veterinary Record, November 22nd, 2003, page 664) described an outbreak in 2003. The condition appears to be commoner in the summer months, but the aetiology remains uncertain.

A combination of large numbers of roundworms Ascaridia galli and the spirochaete Brachyspira pilosicoli was considered to be the cause of poor egg production on one free-range unit, and roundworms and Staphylococcus aureus were demonstrated in a free-range layer that died from egg yolk peritonitis. Productivity on both sites improved after treatment with an anthelmintic and antibiotic.

Game Birds

Several Centres reported deaths in pheasants and red-legged partridges from spironucleosis (hexamitosis). Typical presenting signs were weakness, weight loss, diarrhoea, a hunched appearance and an increase in mortality. Some units described a poor response to medication of the drinking water with tetracyclines because the wet weather had made alternative un-medicated sources of drinking water available. A combination of spironucleosis and heavy gapeworm (Syngamus trachea) burdens was seen in pheasants aged nine weeks and ten weeks, and moderate numbers of motile protozoa were demonstrated in the small intestine of a young red grouse that had been caught by a dog.

The owner of 2,500 red-legged partridges reported the death of some 100 birds aged 10 days over a period of 24 hours. Post mortem examination found that the birds were in good body condition with food in the upper digestive tract. The contents of the small intestine were fluid and thick caseous cores distended the caeca. A heavy growth of Salmonella Typhimurium (phage type RDNC) was isolated from all three birds submitted. Subsequently other outbreaks of salmonellosis were identified in young purchased partridges in the area, suggesting a common source of infection.

Wild Birds

A necrotic oesophagitis consistent with a diagnosis of trichomoniasis was found in chaffinches (Fringilla coelebs) and greenfinches (Carduelis chloris) from eight different locations. The same condition was diagnosed in a collared dove (Streptopelia decaocto) submitted from one of these sites.

Examination of the remains of a peregrine falcon (Falco peregrinus) found dead on an estate identified toxic levels of carbofuran. In 2005 carbofuran was the commonest pesticide identified in poisoned birds in the United Kingdom.