Non-respiratory bacterial diseases in poultry Flashcards
Another term for salmonelloses in poultry.
Pullorum disease
Fowl typhoid
Fowl paratyphoid
These are all caused by different salmonella spp.
Pullorum disease is a disease of chicks caused by
Salmonella pullorum and characterized by septicaemia and high mortality.
Fowl typhoid is a chronic disease of older chicks and adult birds caused by
Salmonella gallinarum, characterized by diarrhea, drowsiness and emaciation.
Fowl paratyphoid is a zoonotic infectious disease caused by
a variety of Salmonella spp., characterized with latent course in birds, but causing
disease in humans who eat inadequately cooked poultry meat or eggs.
Notifiable disease!
Describe Salmonella spp.
Motile, facultatively anaerobic Gram- bacteria.
Zoonotic!
Two species, more than 2600 serotypes.
Salmonella enterica
Salmonella bongori
+ all the various subspp.
Salmonella enterica: six subspecies, S. enterica subsp. enterica has pathogenic serotypes.
Name 2 main subspp. to affect poultry.
S. Pullorum ja S. Gallinarum:
non-motile, variable in size, host-specific (chickens, turkeys, quails, pheasants, ducks, geese and pigeons).
Virulence factors in Salmonella spp.
Virulence factors: fimbriae, invasins, enterotoxins, endotoxins
Which salmonella spp. are more dangerous to humans?
Where do humans get them from?
Salmonella Typhimurium, Salmonella Infantis and Salmonella Enteritidis
Source: fresh chicken eggs and chicken meat, contaminated food, cross
contamination in the kitchen.
Salmonella Pullorum typically affects what age birds?
Causes what?
in chicks up to 3 weeks of age
Septicemia, white bacterial diarrhea
Salmonella Gallinarum typically affects what age birds?
Causes what?
in adults and young birds, but also in chicks
Septicemia, acute or chronic course.
Source of salmonella infection:
Birds (incl. wild birds)
Animals (incl. wild animals and rodents)
Insects (incl. blood-sucking)
Recovered birds become asymptomatic carriers with local ovarian infection.
transmission of salmonella
Excretion: faeces
Transmission:
Direct horizontal: eating eggs, birds, blood-sucking insects, people
Indirect horizontal: contaminated water, feed, fomites, etc.
Aerogenic: aerosols, dust (chicks)
Vertical: transovarial
IP of salmonelloses.
Incubation period: 4-6 days
Recovered birds become asymptomatic carriers with local ovarian infection.
Where is salmonella found?
Salmonelloses are always a threat in poultry farms with gross and intensive production.
Prevalent everywhere. Every year people get infected. One of the four major causes of diarrhea globally.
Salmonella spp. has some resistant serotypes affecting the food chain.
Eggs and meat from infected or sick birds shall not be allowed to be resold or processed for human consumption.
Notifiable disease!
Clinical signs of Pullorum disease and fowl typhoid in chicks.
Peracute illness: sudden deaths
Acute illness: chicks seek heat,
drowsiness, not eating, white pasty
diarrhea, feathers around the cloaca are dirty, wings dropped.
Less commonly blindness, breathing
difficulties, hock joint swelling.
Clinical signs of Pullorum disease and fowl typhoid in older chicks and adult birds.
- Not characteristic
- depression, body temperature increase 1-3’C.
- Loss of appetite, anorexia
- White diarrhoea, dehydration
- Poor plumage, comb paleness
- Breathing difficulties
- Decrease in egg production and fertility
- Joint (especially hock joint) inflammation
- Low mortality
Clinical signs of Fowl paratyphoid
in chicks.
Mortality is highest in the first few weeks of
life - Sudden deaths.
Huddling, Progressive depression, drowsiness, lethargy, closed eyes.
- Droopy wings, poor feathers
- Slow growth, weight loss, anorexia
- Profuse watery diarrhoea, dehydration
- Secondary infection → acute septicaemia.
Clinical signs of Fowl paratyphoid
in older chicks and adult birds.
Clinical disease is not characteristic.
- Decreased egg production and quality
- Infected eggs → high embryonic
mortality. - Anorexia
- Diarrhea
- In some cases, blindness and limping.
Post mortem signs of Pullorum disease and fowl typhoid in chicks.
Peracute (sudden deaths): no findings.
Acute:
* Retained yolk sac, creamy caseous yolk sac contents.
- Enlarged, dense liver, spleen and kidneys
- Greyish-white spots in the liver, white nodules in the lungs, spleen, heart, intestines and gizzard.
- Creamy caseous cecal crusts
- Thickened pericardium, yellow serous/fibrinous exudate in pericardial cavity.
- Swollen joints, accumulation of the yellow viscous liquid
- Excessive exudate in the anterior chamber of the eyes
Post mortem signs of Pullorum disease and fowl typhoid in adult birds.
Damage often minimal.
- Egg follicles of irregular shape, unnatural color, cystic or nodular follicles with oily and/or caseous content.
- Caseous exudate in the oviduct
- White caseous lumps may be present in the lungs and air sacs.
- Swollen, brittle and often bile-stained liver.
- occasionally Fibrinous peritonitis and perihepatitis, adhesions between organs.
- Roosters: white nodules can be found in testicles
Post mortem signs of fowl paratyphoid in both chicks and adults.
- Septicaemia, high mortality, few
visible lesions. - Omphalitis, yolk sac inflammation
- Bloody or watery yellow fluid in a
yolk sac.
Longer course: enteritis, necrosis of
the intestinal mucosa.
- Reddish-brown pseudomembrane
and white to yellow caseous
exudate in the ceca. - Enlarged liver, pale to hemorrhagic foci of necrosis.
- Accumulation of fibrin or fibrinopurulent exudate on the surface of the heart, liver, lungs and other internal organs, as well
as in the eye (hypopyon) and wing or leg joints (arthritis).
Material for Diagnosis of salmonelloses in poultry.
Material: faeces, blood, live birds and
carcasses
Lab analyses for Diagnosis of salmonelloses in poultry.
Analyses: guide to standard procedures in
EU (ISO 6579-1:2017). Strict! You must follow the standards.
Bacteriological analysis: gives a true
diagnosis.
- Faeces, organs cultured on specific media
- Diagnosis is based on isolated and confirmed Salmonella spp.
- Serotyping: White–Kauffmann–Le Minor’
system
Blood agglutination test
- Regular study of 10% of the breeding birds
(Salmonella monitoring plan).
Treatment of salmonella in birds.
Production birds are not treated.
No drug is able to completely eliminate the pathogen.
Other birds:
- Drugs With the feed or water
- Prophylactic and therapeutic treatments