Veterinary Services

Poultry

Increased mortality was reported in a flock of female turkey breeders aged 33 weeks, in their second week of egg production. Some birds exhibited gasping respiration, especially when being handled for artificial insemination. Other birds were found dead. Male turkeys on the site were unaffected. Significant congestion and consolidation of the lungs was a consistent feature in the five birds presented for postmortem examination. All the birds had heavily congested ovules on the ovary, and three birds had a grey fluid peritonitis (figure 3). No significant bacteria or fungi were isolated from the viscera, but an underlying infection with Ornithobacterium rhinotracheale (ORT) was suspected and the flock was treated with an antibacterial agent. Subsequent histopathological examination showed that the birds had a marked acute to subacute fibrinogranulocytic pneumonia and a moderate mucoid tracheitis. Slender rod-shaped bacteria of varying length, consistent with Ornithobacterium rhinotracheale, were noted in the lung lesions. Changes in the management of the turkeys associated with the onset of lay and artificial insemination may have triggered disease.

Elevated mortality occurred in a free-range flock of 16,000 layers. Aggression in the flock had been noted, and some birds may have been stressed by the presence of ewes and lambs in the same paddock. Postmortem examination of three birds showed varying combinations of egg yolk peritonitis, extensive feather loss, and traumatic damage to the vent.

Gamebirds

Pale swollen kidneys and urates on the surface of the heart and liver were found in an adult pheasant from a holding on which 60 out of 2000 birds had died. The findings were considered to be consistent with a diagnosis of pheasant coronavirus – associated nephritis.

Treading injuries, prolapse of the oviduct and heavy gapeworm burdens accounted for increased mortality in adult pheasants on another site.

Rotavirus infection was confirmed in pheasant chicks aged ten days that were reportedly in poor condition on arrival. There was a significant increase in mortality with more than 200 deaths in the batch of 4400 chicks, with some birds showing yellow diarrhoea.

Yolk sac infection associated with E coli was diagnosed in young pheasant chicks. More unusual was E coli associated yolk sac infection in a batch of three-day-old ducklings in which 7 % mortality occurred.

Pigeons

Salmonella Typhimurium phage type 2 was isolated from a pouter pigeon from a loft in which diarrhoea, weight loss and deaths were occurring in adult birds, young birds and nestlings. Pericarditis and hepatomegaly was present at necropsy of one bird, and a second bird had nodules on the serosa of the small intestine and a caseous nodule at the rectum.

Wild birds

Surveillance of wild bird mortality continued in May. As in previous months, many of the submitted wild birds had died from non-infectious causes such as starvation or trauma. Infection with E coli O86 caused deaths in finches such as goldfinches (Carduelis carduelis), greenfinches (Carduelis chloris), chaffinches (Fringilla coelebs) and siskins (Carduelis spinus).

Thickening and necrosis of the oesophagus was noted in a greenfinch and three chaffinches from two different locations. Cultures for Salmonella were negative, and infection with Trichomonas gallinae was suspected. Infection of finches with this organism was first reported in the Veterinary Record in September 2005 (Veterinary Record 157, pages 360 and 455).

Two adult male black grouse (Tetrao tetrix) from different locations were submitted for postmortem examination. One bird had a mycotic pneumonia and a concurrent Staphylococcus hyicus bacteraemia. The other bird had pale-brown frothy intestinal contents and caseous caecal cores, and large numbers of coccidia were demonstrated in smears from the small intestine and caeca. Histopathological examination also found evidence of flagellate protozoa, most likely trichomonads, in the caecal crypts.