Monthly Surveillance Report Published March 2005 Highlights Spiking Mortality Syndrome Pseudomonas septicaemia Ammonia blindness

Salmonellosis

Probable hypoglycaemia (“spiking mortality syndrome”) was the diagnosis for a batch of 21-day-old broilers presented with a history of a sharp increase in mortality, lasting for 3 days. Post-mortem examination revealed congested livers, pale spleens with blood splashes and absence of food in the upper digestive tract.

A definitive diagnosis of this condition, which tends to occur more in winter and often following one or more interruptions of the feed supply, depends on the demonstration of blood glucose levels in moribund birds considerably lower than the published reference range of approximately 7.6 – 20.1 mmol/l.

Pseudomonas septicaemia

Pseudomonas aeruginosa septicaemia and arthritis were diagnosed in 6-dayold layer breeders. Routine cultures of liver, spleen and hock joints produced good virtually pure growths of Pseudomonas aeruginosa. Possible sources of this infection such as the hatchery, contaminated vaccination equipment, and source flocks were discussed.

Ammonia blindness

Ammonia blindness was the most likely diagnosis in 14-week-old commercial layer pullets with a history of eye irritation. The flock had undergone ILT vaccination two weeks or so before submission and the veterinarian in charge wished to rule out the possibility of ILT involvement.

Birds submitted alive were sitting on their hocks with tightly closed eyes and had bilateral corneal opacity and a mild conjunctivitis. Histopathological examination confirmed a mild to moderate kerato-conjunctivitis with small areas of corneal ulceration, but with no evidence of ILT.

Ostrich

Three adult ostriches that had died over a period of 3 days were submitted to Penrith for post-mortem examination. The proventriculus of each bird was full of grit or straw, and in one bird this had impacted. Histopathological examination revealed the presence of a large number of nematodes in the gizzard mucosa.

Differentiation of nematodes can be difficult histopathologically, however, heavy infestations of the wireworm Libyostrongylus Douglas, which lives in the openings of the deep proventricular glands and under the koilin layer of the proventriculus and gizzard, is known to cause a severe gastritis with subsequent gastric stasis. This could have been responsible for the deaths of these three animals.

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Source: Veterinary Laboratories Agency - March 2005