Pullorum Disease

Synonym: Bacillary white diarrhea

• It is an acute, highly fatal disease of young chicks characterized by white diarrhea.
• Earlier, this disease was called bacillary white diarrhea but since diarrhea is not always a sign, later it is known as pullorum disease.
• Disease is acute in young chicks and chronic in adult birds. Adult birds may remain as carrier.

Etiology:

• Salmonella pullorum
• It is gram -ve, non-motile bacteria, measuring 1.0–2.5 mcm by 0.3–1.5 mcm.
• They exhibit host specificity for poultry.

Epidemiology:

• Disease is worldwide in distribution.
• Organism can survive outside the body of host for many months and for several years in favorable environment.
• Mortality from disease is usually confined to first 2-3 weeks of age.
• Pullorum disease is responsible for considerable economic losses in the poultry industry worldwide.
• Disease cause very high mortality rates (potentially approaching 100%) in young chickens and turkeys within the first 2–3 weeks after hatching.
• In adult chickens, mortality rates may be high; however, frequently there are no clinical signs.
• Pullorum disease was once common but has been eradicated from commercial poultry stock in the US.
• Birds < 4 weeks old or younger are most commonly affected.

Transmission:

• Infection spreads in 2 ways:

1. Vertical transmission
2. Horizontal transmission

• Vertical transmission usually occurs through infected eggs. Infection spread to chick through eggs during hatching.
• Horizontal transmission takes place through:
  • Ingestion of contaminated food and water
  • Contaminated utensils
  • Dead embryos, dead chicks
  • Cannibalism of infected birds
  • Egg eating
  • Visitors, rodents and flies

Pathogenesis:

Clinical Findings:

Signs in chicks:

• Signs are variable in nature and not typical.
• In incubator, birds look moribund in appearance.
• Respiratory distress; gasping
• Ruffled feathers and drooping of wings
• Drowsiness, weakness and loss of appetite.
• Huddling together
• Birds disincline to move.
• Excretion of whitish feces; chalky white in color.
• Pasting of feathers of vent region
• A shrill cry while voiding droppings.
• Swelled pot bellied abdomen
• Increased thirst, peculiar chirping sound
• Lameness; swelling of hock and tibiotarsal joints

Signs in adult birds:

• Adult donot exhibit any appreciable sign.
• Reduction in egg laying in laying birds.
• Reduction in fertility and hatchability
• Birds may show inappetance, depression, ruffled feathers and greenish brown diarrhea.
• Dullness and paleness of combs
• Drooping of wings and heads
• Death due to severe dehydration.

PM Findings:

• In chicks, lesion usually includes unabsorbed yolk sac
• Classic gray nodules in liver, heart, spleen, lungs, gizzard, intestine.
• Liver is enlarged, congested, and shows pinpoint nodules, hemorrhage
• Necrotic foci in large intestine.
• Pinpoint nodules in gizzard.
• Hock joints are enlarged due to excess gelatinous material around the joint.
• Abnormal ovary in adult birds; ova is irregular, cystic, deformed, discolored and attached with prominent, thickened stalks.
• Firm, cheesy material in the ceca (cecal cores) and raised plaques in the mucosa of the lower intestine are sometimes present.

Diagnosis:

• Based on history of mortality, reduction in egg production
• Based on clinical findings and PM findings
• Isolation and identification of S. pullorum from liver and intestine.
• Rapid plate agglutination test; colored antigen containing S. pullorum are added in serum separated from poultry blood. The reagent is then mixed and examine for clump. Positive reaction shows clumping within one minute.
• Intradermal test, FAT

Differential Diagnosis:

1. Fowl typhoid:

• Fowl typhoid mainly affects adult birds.
• Liver shows bronze discoloration with white necrotic foci

2. Colibacillosis:

• More fibrinous lesion such as pericarditis and perihepatitis are seen in colibacillosis.
• Chalky white cecal sore are less typical in pullorum.

3. Omphalitis:

• No cecal sores present
• Not contagious like pullorum

4. Coccidiosis:

• Bloody diarrhea
• Cecal sores with blood clots
• It usually occurs after 2-3 weeks of age.

5. IBD:

• Swollen bursa with hemorrhagic lesion
• There is no septicemia.
• Usually seen at age of 3-6 weeks.

Treatment:

• Drugs like sulphonamide, chlortetracycline, Furazolidine and furaltadone can be used for treatment.
• Trimethoprim and Sulphadiazine preparations can also be used.
• Antrima powder @1-2g/litre of water BID for 5-7 days
• Bactrisol powder @500mg/litre of water for chicks BID for 5-7 days
• Sulcoprim powder @ 500mg/litre of water for chicks BID or 1-2 g/litre of water for adult birds BID for 5-7 days.
• Furalin @ 250-500g/ton of feed
• Fucox @50g/50-100 litre of water for 5 days.

Control Measures:

• Proper hygienic measures should be adopted in farm.
• Rapid agglutination test should be adopted as routine measures for screening disease in poultry flock.
• All the breeding stock should be tested with whole blood agglutination test annually or periodical interval.
• Those birds that are positive on PAT should be culled and slaughtered.
• Following removal of dead birds and reactor birds, premises should be disinfected with 3% cresol or commercially available disinfectants.
• Birds should be purchased only from pullorum free flock.
• New birds shouldnot be allowed to enter the farm without testing.
• Infected eggs shouldnot be incubated for hatching.
• Movement of birds should be restricted within the farm.
• Incubators should be fumigated with formalin and potassium permanganate (355 ml of formalin and 17.5g of potassium permanganate for 100 cu. ft area).
• Incubator wastes should be destroyed by burning.
• No commercial vaccine is available for disease.