This document discusses Pullorum disease, a highly contagious bacterial infection of chickens caused by Salmonella pullorum. It is transmitted vertically from infected hens to chicks through eggs. Young chicks are most severely affected, experiencing high mortality rates due to bacteremia. Clinical signs include diarrhea and death within a few days of hatching. Post-mortem lesions include typhlitis, hepatitis, and arthritis. Definitive diagnosis is made through bacterial culture or serological detection of antibodies against S. pullorum.

1. Pullorum Disease
COLLEGE OF VETERINARYAND ANIMAL
SCINCES, PARBHANI
Submitted by
Balaji. M. Jogdand
M.Vsc Scholar,
Dept. of Vet Pathology

2. Introduction:
Pullorum disease is a highly contagious, egg-transmitted disease.
It is mainly a blood infection of chickens. The disease is characterized by white
diarrhea in young chicks.
Young chicks and turkey poults (Less than 4 weeks) commonly affected- very high
mortality (up to 100%) ; adults - asymptomatic carriers.

3. Etiology
A non motile, gram negative, rod shaped bacterium Salmonella pullorum

4. Route of infection/Spread/Transmission
The most important method of spread is vertical transmission. That is. from an infected
hen through the eggs to the newly hatched chicks.
 Newly hatched chicks spread the infection to other chicks in hatcheries through their
soft feathers which are heavily contaminated by S. pullorum.
Affected chicks shed S. pullorum through the faeces. This is the major method of
spread among chicks.
Contaminated feed, water and litter.
Attendants, visitors, feed dealers, and chicken buyers who move from house to house
and from farm to farm, may carry infection.
Incubation period is 4 to 10 days

7. Pathogenesis
The organisms enters in blood, multiply and leads to bacteremia.(fatal in young chicks)
The bacteremia subside with organism becoming localized in various organs in which
necrotic foci are setup .
Exacerbation and flare up of disease occurs when the animal are exposed to
debilitating influencers such a change in weather, prolonged transport, and sudden
change in feed.

8. Sign & Symptoms
Disease occurs mainly in chicks under 3 weeks of age.
First indication is excessive numbers of dead-in-shell chicks & death soon after
hatching.
Depression with a tendency to huddle with respiratory distress
White viscous (thick and sticky) droppings which adhere to the feathers around the
vent.
The mortality varies considerably, and in extreme cases can be 100%.
A subacute form with lameness and swollen hock joints may be seen in growing birds,
Reduced egg production may be the only sign of the disease in adult birds.

9. Pullorum disease in a chicken.
Note liver is enlarged, congested, and shows
small necrotic foci (minute white spots). Such
necrotic foci are highly suggestive
of pullorum disease.
Pullorum disease in a mature hen showing
lesions (changes) in the ovary. Note ova
are irregular. cystic. deformed and
pedunculated with prominent thickened
stalks.

10. Lesions
Chicks:
If death soon after hatching;
 Peritonitis with an inflamed, unabsorbed yolk sac
 Lungs: congested
 Liver: Dark, swollen, haemorrhages on the surfaces
 If die in the acute phase-no specific lesions, or those of septicaemia
 If death after showing signs for 1 or 2 days
Typhilitis: enlarged and distended with casts of hard, dry necrotic material.
Discrete small, white, necrotic foci in the liver, lungs, myocardium, and gizzard wall.
In general, the lesions in chicks are neither characteristic nor consistent.

11. Growers
Arthritis - Hock joint - Enlarged due to the presence of excess orange colored
gelatinous
material around the joints.
Adults
Abnormal ovary: Irregular ova cystic misshapen discolored pedunculated with
prominent thickened stalks.
Inactive ovary with the small, pale, and undeveloped (in some cases)
Peritonitis, arthritis and pericarditis.
Lesions cont…

12. Diagnosis
Tentative diagnosis - History, signs and lesions
Confirmatory diagnosis - Isolation of the causative agents by cultural examination.
 Detection of antibodies by agglutination tests (rapid slide agglutination test
on whole blood using a stained antigen, and a tube agglutination test carried out on
serum)