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
Prevention of salmonelloses in birds.
biosecurity, vaccination
Strict veterinary sanitary regulations & National control programs.
Rules for the control of salmonellosis (surveillance).
Vaccination, longer downtime
Control of wild birds, rodents and other pests
New chicks from serologically tested flocks
Prevention of pullorum disease: spraying eggs with neomycin and fumigation.
Surveillance of salmonelloses.
The prevalence is continuously
monitored at farm level.
- Before slaughter, in slaughterhouses,
before the start of lay.
Only Eggs and meat from farms, where
Salmonella spp. is monitored, can be
sent to the food industry (otherwise youre unable to sell it).
For bacteriological examination;
fecal and cloacal swabs, or sock samples are collected and tested.
What is a sock sample/boot swab?
a method used to collect environmental samples from poultry houses.
Before changing/refreshing bedding.
Special socks are placed on sterile footwear.
Walking at least 100 steps to cover the entire building and all departments.
The stool should remain on socks → dirty.
Socks removed from the shoes are placed in a sterile container. Samples must be immediately and accordingly sent to the
laboratory. Samples must not be in a hot environment before testing.
Review this table on sample types in salmonella surveillance.
sock samples, fecal samples, and other samples can be taken.
from egg-layers, meat birds or other flocks.
Salmonella Control program in Finland
Vaccination of birds and treatment with antimicrobials is prohibited.
Less than 50 birds on the farm → rules are not so tight.
Active monitoring: regular sample collection and investigation –
frequency depends on bird species and production goal.
Samples represent all the birds in the farm.
The result is known before the birds are sent to the slaughterhouse.
Resampling and testing 6 weeks later (if necessary).
Where and when needed, the study of feedstuffs is done.
If a sample if found positive for salmonella:
Positive sample: slaughtering of birds, sending eggs for sale or meat for poultry production, or introduction of new birds is prohibited.
Sending birds for eradication is allowed, but the farm is quarantined, dogs must not roam the farm freely.
Decontamination program: emptying, cleaning and disinfecting buildings, followed by testing.
Pos. result → it’s necessary to redo the
decontamination
Neg. result → the aviary can be repopulated
Clinical signs of Salmonellosis in humans
Incubation period: 6-72h, if not treated, acute phase lasts 4-7p, carrier status for 2
months afterwards.
Stomach cramps, fever, vomiting and diarrhea, tenesmus.
Reactive arthritis, eye irritation, painful urination rare.
Diagnosing Salmonellosis in humans
Diagnosing via faecal and blood samples (antibodies), vomited masses, food residues.
DNA fingerprint, serotyping and culture, electrophoresis
Treatment of Salmonellosis in humans
Fluid therapy + broad-spectrum AB, elongated periods.
Empirical treatment: ampicillin, biseptol, fluoroquinolones, gen. III cephalosporins,
ciprofloxacin.
Resistance plasmids: fluoroquinolones, gen. III cephalosporins.
Course of disease in Cl.perfringens.
Clinical signs?
Post mortem findings?
Acute or subclinical.
Signs: bloody diarrhea, salivation, depression, death in 3 days when acute.
Post mort.: SI mucosa thick, hemorr., necrotized. Hepatomegaly with hemorr.
Spleenic atrophy.
Course of disease in Cl.colinum.
Clinical signs?
Post mortem findings?
Acute or chronic.
Clin.signs:
sudden death
hemorrhagic enteritis
kyphosis (hunchback)
Post mort.:
SI hemorrhagic enteritis
GI tract ulcers
peritonitis
liver/spleenic necrosis
Cl.botulinum.
Clinical signs?
Post mortem findings?
Clin.signs:
diarrhea
visual, auditory, resp. impairment
paralysis
Post mort.:
gaseous gangrene
enterotoxemia
parenchymal organ necrotic inflammation
Clinical signs of colibacteriosis.
Review this table.
Post mortem signs of colibacteriosis.
Review this table.
Clinical signs of Campylobacteriosis in chicks.
Incubation period 1-4 days
- Lethargy, anorexia
- Diarrhoea (usually yellowish in colour, small amount of blood may occur)
Clinical signs of Campylobacteriosis in adults.
In the peak period of egg laying, in
free range systems.
- Decrease in egg production up to 25%
Sudden deaths: septicaemia and
toxaemia.
- Dull, ruffled, discoloured feathers
- Beak/nail overgrowth
- Lethargy, weakness
- Shrunken comb
- Signs do not occur in all birds
Post mortem signs of Campylobacteriosis in chicks.
- Enlarged, pale or greenish liver
- Catarrhal/haemorrhagic enteritis, mostly in the end of small intestine and caeca
- Mucus and blood in the intestinal content
Post mortem signs of Campylobacteriosis in adults.
- Focal hepatic necrosis of various
degrees of severity (spotted liver) - The liver may be slightly enlarged with moderately rounded edges
- Foci of necrosis may coalesce
Campylobacteriosis in humans
Source: uncooked or insufficiently cooked
poultry products, raw milk, contaminated
water.
Most common source: poultry meat (> 50%).
Poultry carcass gets contaminated when
intestines are broken, milk contamination occurs with bad milking hygiene.
Prevention: good personal hygiene
Food warming over +70 °C, poultry meat over +75 °C.
Storing food over +60 °C or below +6 °C.
Care when preparing raw meat.
Clinical signs of poultry erysipelas.
Post mortem signs of poultry erysipelas.
