Veterinary Services

Poultry

Reduced egg production and increased mortality was reported in a flock of 2000 free-range hens. Four birds submitted for post mortem examination were in poor to emaciated condition, weighing between 800g and 1200g. In all birds the digestive tract had become impacted with grass, at varying levels from the crop to the distal small intestine. In one bird the gizzard had ruptured and there was an associated peritonitis. Very little grit was present in the gizzards.

Significant ectoparasitism was confirmed in a layer submitted from a unit with approximately 250 poultry, including ducks, geese, chickens and quail. Large numbers of northern fowl mite (Ornithonyssus sylviarum) and fluff lice (Goniocotes gallinae) were observed.

Turkey hepatosis or cardiohepatic syndrome was suspected following the histopathological examination of tissues from a four-week old turkey poult. The unit had reported 20 deaths in a group of 150 turkeys over the preceding few weeks. The condition is often seen in turkey poults that grow particularly well early on but then develop an irreversible congestive heart failure. The cause or causes are uncertain.

Marek’s disease was found to be the cause of ill thrift in two birds out of a flock of 20. The birds were one year old and had been bought in.

Gamebirds

The commonest pathogen causing problems in red-legged partridges and pheasants was Spironucleus (Hexamita) meleagridis, often causing significant weight loss in released birds. In one batch of partridges aged six months the major complaint was that some birds appeared weak and unable to fly. Submissions were received from another estate because some birds had been noted to be thin after they had been shot. Emaciation and increased mortality were the major presenting signs in pheasants aged 10-12 weeks, and on one site a combination of spironucleosis and syngamiasis was responsible for poor body condition in partridges.

Total worm counts in caeca from nineteen red grouse from one estate ranged from zero to 7,100 Trichostrongylus tenuis. On another estate three out of seven birds had worm counts over 3,000, and on a third estate four out of eight birds had worm counts in excess of 3,000.

Aspergillosis was diagnosed in partridges aged 12 weeks. The birds were housed and some 30 to 40 of the group of 150 were ill thriven. Post mortem examination revealed caseous necrotic nodules in the lungs and Aspergillus species was isolated. Poor air quality and infection from the bedding were considered to be the likely predisposing factors.

Pigeons, cage and aviary birds

Salmonella Typhimurium was isolated from pooled faeces from racing pigeons with diarrhoea. Deaths in adult pigeons were attributed to a pigeon herpesvirus infection – post mortem examination of the one bird submitted revealed extensive yellow caseous necrosis in the oesophagus and crop. Aspergillus fumigatus was isolated from the lungs of a yearling pigeon from a loft in which two birds had died. A focal pneumonia was detected at post mortem examination.

Large numbers of avian gastric yeasts ("megabacteria") were demonstrated in proventricular smears from a young Border canary from a collection where young birds were losing weight and dying.

An adult macaw was observed to be gasping for breath and died shortly afterwards. Internal haemorrhage from the area of the ovary was found at post mortem examination.

Garden birds

A presumptive diagnosis of trichomoniasis was made in 19 garden birds from numerous different sites. Affected birds had a severe necrotic oesophagitis, frequently causing partial or complete obstruction of the oesophagus. Most of the submitted birds were greenfinches (Carduelis chloris) or chaffinches (Fringilla coelebs) but lesions were also found in a house sparrow (Passer domesticus).