Avian Salmonellosis Flashcards
Salmonella spp. characteristics
- G-neg rods
- non-motile serotypes
- Salmonella gallinarum (“fowl typhoid”)
- Salmonella pullorum (“pullorum disease”)
- motile serotypes
- many paratyphoid salmonella
Pullorum Disease/Fowl Typhoid: general facts
- septicemic diseases
- primarily affects: chickens, turkeys, guinea fowls
- low incidence in commercial poultry in the US - persists in backyard flocks
Pullorum Disease/Fowl Typhoid: Etiology
S. enterica subsp. enterica pullorum
S. enterica subsp. enterica gallinarum
Pullorum Disease/Fowl Typhoid: Transmission
= direct and indirect
- carriers lay infected eggs»_space; infected hatch»_space; infection to healthy chicks in the hatchery»_space; brooder house mortality»_space; diseased chicks»_space; shed organism in feces and respiratory excretions»_space; contaminate environment»_space; horizontal/indirect transmission»_space; outbreak in flock
- carriers intermittently shed organism in feces»_space; contaminate environment»_space; horizontal/indirect transmission»_space; outbreak in flock
Pullorum Disease/Fowl Typhoid: Symptoms in chicks
= more severe than in adults!
- moribund and dead (piped) chicks, low hatchability
- high mortality in brooder house with signs of:
- incoordination
- respiratory distress
- thirst
- huddling together
- pasting of vent w/ chalky, brown excreta
- a few with hock joint swelling and blindness
Pullorum Disease/Fowl Typhoid: Symptoms in adults
= less severe than in chicks!
- no signs of acute infection or carrier birds
- in severe outbreaks:
- anemia
- depression
- intermittent diarrhea
- low mortality
Pullorum Disease/Fowl Typhoid: Lesions in chicks
- many piped (dead in shell) embryos
- omphalitis
- liver and spleen enlarged and congested with pinpoint necrotic foci
- lung abscesses in 5-10% of chicks
- heart: necrotic foci or nodules (=mononuclear cells)
- hock joint synovitis (viscous, yellow fluid)
- kidneys congested with urates present
Pullorum Disease/Fowl Typhoid: Lesions in adults
- lesions in ovaries:
- chronic asymptomatic carriers
- misshapen follicles
- pedunculated ova
- acute outbreaks:
- lesions in ovaries similar to chronic carriers
- liver and spleen as in chicks (enlarged and congested with pinpoint necrotic foci)
Pullorum Disease/Fowl Typhoid: Diagnosis
- history and CSs
- DDx includes:
- Lung lesions = fungus
- joint lesions = mycoplasma, viral arthritis, mineral deficiency, etc.
- septicemia = fowl cholera, E. coli
- preferred specimens for culture:
- acute = liver
- chronic = ovary…+/- liver, spleen, BM, etc.
Pullorum Disease/Fowl Typhoid: Treatment
= depends on type of bird and country’s policy
- abx only decrease mortally
- no treatment eliminates the infection
Pullorum Disease/Fowl Typhoid: Prevention and Control
- free flocks developed in chickens and turkeys via:
1. elimination of carriers
2. management procedures
3. incubator and hatchery hygiene - vax for fowl typhoid…not available in US
- live vax @ 9-10 wks old
- 8-9 mo. immunity
- interferes with blood testing!
Paratyphoid infection: General info and Etiology
- infection with motile salmonella subtypes
- hosts = avians, dom. and wild animals, humans
etiology = S. enterica…6 subspecies…many serotypes!
Paratyphoid infection: Symptoms in chicks
- symptoms similar to fowl typhoid/pullorum disease
- high # of piped/dead embryos in incubator
- chicks stand w/ eyes closed, head lowered
- ruffled feathers
- diarrhea with pasted vent
Paratyphoid infection: Symptoms in growers
- loss of appetite
- diarrhea
- dehydration
Paratyphoid infection: Symptoms in adults
- chronic carriers of the organism in the intestines
- no clinical signs!
