salmonela pullorum part 2

pathology

the newly hatched chicks wich die from the disease may not show any gross lesion, some of them may show haemorrhagic streak on normally yellowish liver of a newly hatched chick. the chick, which die later, may show greyish necrotic spots of 1 to 2 mm size in the liver; rised, white spot on heart (pericarditis) and spleen.

The caeca may have semi sholid, cheesy material (cores) inside. Unabsorbed an cangulated egg-yolk in another important lesion.

For the test:

the wing vein of the bird is punctured and blood is taken on a platinum loop of 3/16 in diam, (about 0.02 ml of blood) one drop of antigen.

which is placed ready on the clean glass-plate is mixed with teh blood in the bacteriological loop.

Both are mixed by rotating the glass-slide for about 2 minutes. in positive cases clumps of antigen will be seen. Te reacrion is graded as below:

++++: Imediate clumping on mixing: large clumps in coloured fluid are seen.

+++: clump are seen within 1 1/2 to 2min. but clumps are large as above.

++: fine clumps in colourless fluid

+: fine clumps in slightly coloured fluid.

The test should not be done at temperature below 23.5c . otherwise it should be done at 37.5 celcius in an incubator.

the test can be done at the poultry farm.

Read also prev article salmonela pullorum part 1

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