Salmonellosis is caused by Salmonella bacteria, including S. pullorum and S. gallinarum. S. pullorum causes pullorum disease (bacillary white diarrhea), a septicemic disease primarily in chickens and turkeys seen as excess dead chicks and mortality up to 60% in chicks under 3 weeks. S. gallinarum causes fowl typhoid, an acute or chronic septicemic disease in mature birds with mortality up to 100% characterized by swollen liver with necrotic foci and a bronze sheen. Other Salmonella serotypes like S. typhimurium and S. enteritidis cause paratyphoid infections in poultry and foodborne

1. Salmonellosis
• Genus Salmonella consists of more than 2300
serologically distintinguishable varieties
• All species of salmonella except, S.pullorum,
S.gallinarum are usually motile and have long
flagellae
• These two sps are host specific for avian species.
• Pullorum disease is caused by S pullorum. It is an
acute disease of chicks and poults.
• Fowl typhoid is caused by S. gallinarum and it is a
acute or chronic septicaemic disease affecting
mature birds.

2. • The second group includes infection with
motile salmonella serotypes referred to
collectively as paratyphoid salmonellae
S.typhymurium and S.enteritidis
• Paratyphoid infections are important mainly
as a cause of food borne disease in humans.
• Mortality upto 100%, increases during stress
and immunocompromised flocks

3. Pullorum disease (Bacillary white
diarrhoea)
• Pullorum disease is caused by bacterium
Salmonella pullorum.
• It was previously known as bacillary white
diarrhoea or BWD.
• It is septicaemic disease affecting mainly
chickens and turkeys.
• S.pullorum is Gram negative, nonmotile rod
0.3-0.5 x 1.25 μm and has no flagellar or H
antigen

4. • Usually grow on direct culture on MacConkeys
agar as pale, non lactose fermenting colonies
• S. pullorum differs from S. gallinarum in its
inability to ferment dulcitol and maltose and
fermented by S. gallinarum
• Survive outside body for many months
• Mortality upto 60% in chicks ( mostly upto 3
wks of age) and 20% in adults
• Morbidity 1- 80% may reach upto 100%

5. Species affected
• Mainly domestic chicken
• Turkeys
• Ducks
• Pigeons
• Guinea fowl
• Pheasants
• sparrows

6. Spread:
• Horizontal and vertical(transovarian)
• The important method for spread is transovarian
transmission.
• A portion of infected birds become adult carriers with
S.pullorum persisting in the ovaries excreted in the ova.
• These birds become poor layers
• The fertility and hatchability of infected egg is also
below average.
• Contaminated feed, water and fluffs

7. • However viable chicks do hatch from such
infected eggs and remain as source of infection.
• Fluff from such chicks is heavily contaminated
with S.pullorum and it dries, the bacteria are
disseminated through the incubator or brooder.
• Pasty white in the vent area
• Both vertical snd horizontal transmission occurs.

8. Signs:
• Pullorum is seen in chicks under 3 weeks of age.
• First indication is excess numbers of dead in shell
chicks and death soon after hatching.
• Inappetence, depression, tendency to huddle,
respiratory distress(gasping), closed eyes, loud
chirping, white viscous droppings which adhere
to the feathers around the vent.
• The mortality can be 100%.

9. • A subacute form with lameness and swollen,
hock joints(arthritis) may be seen in growing
birds and result of poor growth rates.
• Many remain as carriers and disseminators of the
etiological agents
• Older birds may appear listless, depression and
have pale and shrunken combs with white
diarrhoea
• Reduced egg production may be the only sign of
the disease in adult birds.

10. Lesions:
• Chicks which die soon after hatching have
peritonitis with inflammed unabsorbed yolk
sac.
• Lungs may be congested, liver is dark and
swollen with haemorrhages. Necrotic foci
lungs, liver, spleen and heart
• In chicks which die after showing signs of
disease for 1-2 days, there may be typhlitis.

11. • The caeca are enlarged and distended with casts
of hard dry necrotic and cheesy material.
• Spleen enlarged
• Urates distended with urates
• Discrete small white necrotic foci in liver, lungs,
myocardium and gizzard wall.
• In adult birds abnormal ovary- ova are irregular,
discoloured, cystic, misshapen pedunculated with
prominent stalk
• Pericarditis peritonitis and arthritis

13. Salmonellosis

14. • In growers affected with arthritis. Hock joints
are enlarged.
• In chicks lesions area not constant.
• In adult birds abnormal ovary with irregular
cystic, misshapen, haemorrhagic, atrophic,
discoloured pedunculated with prominent
thickened stalks.
• Oviduct impaction, peritonitis and ascites
• Peritonitis and pericarditis is also common.

16. Diagnosis:
• Typical history, signs and lesions
• Isolation of the causal organisms
- Mckonkey’s Agar
- Xylose Lysin Deoxycholate(XLD) Agar
- Bismuth Sulphite Agar(BSA)
• Rapid plate agglutination test after 16 weeks of age -
>2min positive, within 30 sec positive
• Tube agglutination test
• ELISA
• PCR

17. Fowl typhoid
• Primarily of chicken and turkeys
• Most outbreaks occur in recently hatched
young birds
• Fowl typhoid is caused by S. gallinarum.
• A short bacillus 1-2 μm long and 1.5 μm broad
and don’t poses flagellae
• This organism shares many antigens with S.
pullorum

18. • Readily grows in blood agar and MacConkeys
agar as pale, non lactose fermenting colonies
• Ferments glucose , mannitol, maltose and
dulcitol but does not ferment lactose, sucrose,
and salicin
• It is septicaemic disease affecting mainly
chicks and growers or adult birds although
chicks can be infected.
• Morbidity 10- 100% and Mortality upto 100%

19. Spread:
• Vertical and horizontal
• Organisms are passed in droppings.
• Lateral spread is by ingestion of contaminated
food or water.
• Recovered birds remain carriers for long period of
time.
• Egg transmission also occurs.
• Transmission can occur by contact, attendant,
visitors and contaminated materials.

20. Signs:
• increase in mortality in chicks and continuous
mortality in adults (>50%)
• anorexia, drop in egg production.
• Watery mucoid yellowish diarrhoea and soiled
vent.
• Depression and ruffled feathers
• Reluctant to move

21. • Shrunken pale combs and wattle
• In sub cute outbreak sporadic mortality over a
long period.
• In chicks signs are similar to pullorum disease.
• Increase in dead in shell embryos and dead
chicks in hatching trays

22. Lesions:
• Swollen friable liver with multiple necrotic
foci.
• Surface has a characteristic coppery bronze
sheen.
• Spleen enlarged with necrotic foci and
enlarged kidney
• catarrhal enteritis.

23. • In chronic phase include emaciated and
intensely anaemic carcass with focal necrosis
in heart, intestine,liver heart.
• Necrotic foci in liver, lungs, myocardium and
gizzard.
• In laying bird rupture of yolk occurs.

24. Fowl Typhoid(Bronze coloured Liver)

25. Diagnosis:
• Bacerial culture, Isolation and identification of
organisms
• Rapid plate agglutination test
• Tube agglutination test
• ELISA
• PCR

26. Whole blood agglutination test
• Coloured pullorum antigen available
commercially
• Wing vein punctured
• One drop of blood transferred to a clean slide
(30 µl)
• 30 µl of coloured pullorum antigen mixed with
blood and mixed with the micro tips and by
rotating the glass slide for 2 min
• Observe for clumping
• Clumping in positive cases

27. Differential Diagnosis
Dextrose Mannitol Dulcitol &
Maltose
Litmus ilk
S.Pullorum Fermented
with gas
Fermented
with gas
Not fermented Little and in 18-
72 hrs
S.gallinarum Fermented
without gas
Fermented
without gas
Fermented Fast acid
production

28. Salmonellosis- Avian paratyphoid
• Food borne disease trnsmission to humans
• Salmonellosis, there are > 2300 serotypes isolated from
poultry.
• S.typhimurium
• S.hadar
• S.enteritidis
• S. Heidelberg
• S. montevideo
• S. kentucky
• It rarely cause clinical disease in chicks > 3 weeks of
age.

29. Pathogenesis:
3 type of toxins are reported
• Endotoxin- cell wall polysacharide(LPS)- fever,
liver and spleen lesions,
• Enterotoxin(heat labile)-Increased secretory
response in epithelial cells. Causes fluid
accumulation in the intestinal lumen.
• Cytotoxin(heat stable)- Structural damage to
epithelial cells.

30. Spread:
• It is spread by contaminated feed(animal protein,
fish meal, bone meal etc),
• animal and insect vectors( rats, mice, cockroach).
• It can be transmitted both by vertical
transmission and horizontal transmission.
• It is spread by contaminated faeces and water in
feed.
• S.enteritidis: Organisms enters as eggs get cooled

31. Signs:
• mortality of chicks >3 weeks of age
• Ruffled feather, droopy wings, diarrhoea and
pasty vent, dejection, closed eyes and loss of
appetite
• Ducklings, young turkeys. Mortality< 20% is
recorded. Diarrhoea, pasty vent is common.

32. Lesion:
• Dehydration and enteritis
• congestion and necrotic lesions in liver.
• Swollen liver, spleen and kidney.
• Unabsorbed yolk sac is common feature.
• Haemorrhagic enteritis
• Typhlitis is characteristic(cheesy core in Caeca).
• Distention of caeca with white necrotic cores.
• Peritonitis, enteritis and caecal coring are
pathognomonic.

33. Diagnosis:
• Isolation of organisms from liver, gall bladder,
yolk, and caecum( Brlliant green Agar and Mc
Conkeys.
• Whole blood agglutination tesi
• ELISA
• PCR

34. Salmonella colour antigen

35. Culture of Salmonella

36. Identification of salmonella by
Fermentation reactions
Lactose Maltose Dulcitol
Avian salmonellae No change Acid and gas Acid and gas
S.pullorum No change No change No change
S.gallinarum No change Acid Acid
E.coli Acid and gas Acid and gas Acid and gas