Veterinary Services

Poultry

Myeloblastosis was diagnosed in an adult bantam layer. The liver of the bird was greatly enlarged and contained miliary white foci, and the spleen and kidneys were also enlarged. Histopathology showed neoplastic infiltration of affected organs consistent with myeloblastosis. Substantial weakening of the femur was noted at post mortem examination, possibly due to tumour infiltration of the bone marrow. A different bird submitted from the same flock also had enlargement of the liver, spleen and kidney, with white foci in the liver and kidney, but histopathological examination of tissues from this bird showed evidence of Marek’s disease.

Leg weakness and mortality was reported in a small flock of free-range broilers. Necrotic pododermatitis and septicaemia associated with Staphylococcus aureus was found in the single bird submitted for post mortem examination. Heavy rainfall had caused a deterioration of the birds’ environment, which may have predisposed to the staphylococcal infection.

Coccidiosis was responsible for weight loss and death in chickens aged eight weeks. Brachyspira pilosicoli was detected by polymerase chain reaction (PCR) and bacterial culture from the faeces of layers with diarrhoea and a drop in egg numbers of approximately ten per cent. B. pilosicoli and/or B. intermedius were identified in three broiler farms with growth rates reduced by 10-15% and with sticky faeces.

Game birds

A seven-month old male capercaillie was euthanased after it developed torticollis. Histopathology of the brain demonstrated a severe non-suppurative meningo-encephalitis affecting all levels of the brain but especially the cerebellum. Such neuropathological changes suggest a viral, mycoplasmal or protozoal cause, and similar lesions have been seen in the brains of capercaillie with Sarcocystis infection.

Wild Birds

January saw the seasonal increase in submissions of garden birds with salmonellosis. Salmonellosis was diagnosed in twenty-four birds from 13 sites – 14 greenfinches (Carduelis chloris), 6 chaffinches (Fringilla coelebs), 3 siskins (Carduelis spinus) and 1 goldfinch (Carduelis carduelis). All isolates were Salmonella Typhimurium DT40 or DT56 (variant).

A chaffinch and a collared dove (Streptopelia decaocto) were recovered from a site where multiple deaths had occurred in both species. Lesions typical of trichomoniasis were present in both birds, but it was not possible to demonstrate the organisms because of the delay between deaths of the birds and examination of the carcasses.

Two mute swans (Cygnus olor) and a herring gull (Larus argentatus) were submitted from three different locations. All three birds had a mycotic airsacculitis associated with Aspergillus fumigatus.