Systemic diseases Flashcards
most common, most widely prevalent, and economically the most important bacterial pathogen of poultry
E. coli
Clinical signs & diagnosis:
1. blood infection (colisepticemia)
2. yolk sac infection
3. egg peritonitis
Colibacillosis
omphalitis & salphingitis
Colibacillosis
Predisposing factors:
1. contaminated water and feeds
2. overcrowding
3. poor ventilation
4. poor litter
5. ammonia
6. stress
7. immunosuppression
Colibacillosis
exudation in heart can easily migrate in abdomen to reproductive organs
Colibacillosis
magnify the effect of colibacillosis
cold stress
Encephalitis if migrated in the brain
E. coli
Control of coli
begin with: complete sanitation program in surroundings and various environmental stresses
caused by
Pasteurella multocida
Fowl cholera
- septicaemic disease of chickens
- disease occurs in several forms
- wattle = filled with pus
Fowl cholera
Form of cholera
- no preceding symptoms
- sudden spike in mortality
- apparently good body condition
Severe cholera
Form of cholera
* marked depression
* loss of appetite
* mucus discharges
Less severe cholera
Form of cholera
* birds that survive the severe disease
* depression, difficult breathing
* later manifestation: lameness, twisting of the neck, swollen wattles
Chronic cholera
cheesy exudates, bacterium
Cholera
severe form of ____ is so rapid that treatment is futile
Fowl Cholera
Fowl cholera
hemolytic or non-hemolytic?
non-hemolytic
Fowl cholera
gram stain?
gram-negative
caused by Salmonella pullorum
Mortality usually at the first 2-3 weeks
Pullorum disease
Vertical transmission:
* most important route of infection (in ovo)
* infected chicks shed S. pullorum through in feces
* other sources:
1. contaminated feed
2. water
3. litter
4. pedunculated ovum
Pullorum disease
Mainly a disease of young birds;
• chicks below 3 weeks of age
• rare in adult birds
Pullorum disease
Mortalities:
1. inflammation of the caeca (enlarged, distended with hard, dry, necrotic material)
2. distinct, small, white, necrotic foci (dead tissue) usually found in the liver
Pullorum disease
Clinical disease without external signs:
1. mainly poor production performance
2. at necropsy: pedunculated ova (oviduct)
Pullorum disease
Diagnosis for pullorum disease
Test the blood of breeders
Control for pullorum
- purchase infection-free replacement stock
- hatchery: salmonella free eggs
caused by Salmonella gallinarum
Fowl Typhoid
Vertical and horizontal transmission
Infected flocks signs:
• increased mortality (5-10% weekly)
• diarrhea
• depression
• declining production performance
Fowl Typhoid
Diagnosis for fowl typhoid
- Isolation
- Plate agglutination
- (+) 2 weeks after infectoin
Vaccination (bacterins)
Fowl Typhoid
caused by:
* S. enteritidis
* S. typhimurium
* S. agona
* S. heidelberg
Salmonellosis Paratyphoid
Vertical and horizontal transmission
rodents & beetles reservoirs
Salmonellosis Paratyphoid
Infected flock:
* 3% chick mortality
* at the first 2-weeks of life
Salmonellosis Paratyphoid
Clinical signs:
* may resemble pullorum disease
* (E.g., high mortality, poor uniformity, omphalitis, enteritis, peritonitis, splenomegaly, hepatitis, typhlitis or cacum inflammation)
Salmonellosis Paratyphoid
Confirmatory for s. paratyphoid
Microbial isolation & ID
Only vaccines for s. paratyphoid
- S enteritidis
- S typhimirium
Clinical signs:
1. ruffled feathers
2. limping
3. hanging downwards of one or both wings
4. fever
5. severe depression
6. death
Staphylococcosis
abrasion in foot pads
“cheesy exudates” in joint
Staphylococcosis
Control:
1. Sensitivity tests should always be performed because antibiotic resistance is common
2. Maintenance of good litter quality will reduce foot pad ulceration
Slatted floor
Staphylococcosis
Caused by
1. M. synoviae (serous arthritis)
2. E. coli
3. Staphylococcus aureus (purulent/Staphylococcal arthritis)
Arthritis – Bacterial
Infection of the synovial fluid in the joints
* arthritis
* manifests as lameness
* inability to stand
Arthritis – Bacterial
Morbidity and mortality may reach 20%, carcass quality is also reduced
Arthritis – Bacterial
- vertical & horizontal (Mycoplasma spp.)
- horizontal (Staphylococcus spp.)
Arthritis – Bacterial
Two (2) specific Reovirus serotypes that caused arthritis (reoviral arthritis C)
- S1122
- WVU 2937 (arthritis & tenosynovitis)
Occurs worldwide; losses in broilers and breeders
can be a complication of
“Helicopter feather disease”
Arthritis
– Reoviral arthritis C
Birds ±30 days old
lameness unilateral / bilateral arthritis (hock, stifle)
Arthritis
– Reoviral arthritis C
gastrocnemius tendon may rupture
Arthritis
– Reoviral arthritis C
Transmission:
1. vertical (egg)
2. horizontal (carriers)
3. fomites
4. poor hygiene
Arthritis
– Reoviral arthritis C
Aka: Malabsorptive Syndrome; specific causal agents has not been identified
• most likely multifactorial in nature
• mapapatagal harvest
Specific reovirus strains (E.g.,1733) has been implicated
Runting-Stunting Syndrome
Poor growth rate, elevated chick mortality (2-5%) at 5-7 days old
(morbidity up to 100%)
Yellowish feathering at 3-4 wks old
• abnormal wing feathering
• helicopter disease
Runting-Stunting Syndrome
finger-like intestinal villi
Runting-Stunting Syndrome
Inclusion bodies – fragments of viral DNA
Runting-Stunting Syndrome
Vaccination at 4-5 days old with boosters at 30-40 days old
Reoviral infection
can cause septicemia or endocarditis
spread through aerosols, oral route, injury
Streptococcosis
Streptococcus species
- S. equi subsp zooepidemicus (S. gallinarum)
- S. gallolyticus subsp gallolyticus (S. bovis)
- S. dysgalactiae
- S. gallinaceus
- S. mutans
- S. pluranimalium
- S. suis
Diagnosis for strep
Bacterial isolation
localized or septicemic
Endocarditis and lameness occur at the subacute or chronic stages
Bloodstained feathers around the mouth and head
Hematemesis has been reported
Flock mortality: ±50%
Streptococcosis
considered part of normal microbiota
clinical infections usually occur secondary to a primary pathogen
Streptococcosis
Young birds are apparently more susceptible; birds are depressed, with cyanosis of the of the head
Enlarged mottled spleen, hepatic necrosis
Sub acute & chronic: paresis (weakness), paralysis, and death
Mortality may reach 30%
Spirochetosis
(3) vectors of Spirochetosis
Soft-shelled tick vector: Argas spp.
Mites: Dermanyssus spp.
Mosquito: Culex spp.
Caused by Borrelia anserina (spiral bacteria)
occurs in tropical countries
Spirochetosis
Eradicate the vectors
spirochetosis
Diagnosis of spirochetosis
- Giemsa stain slides
- Spleen inoculation
- Homogenate into SPF eggs
(3) diseases associated with Fowl Adenovirus Infection
- Adenoviral gizzard erosion (AGE, Serotype 1)
- Inclusion body hepatitis (IBH, Serotype 8a, 8b, 11)
- Hydropericardium-Hepatitis Syndrome (HPS/HHS; Angara disease) Serotype 4
Affected flocks show wasting, poor performance, and increased mortality
Synergism with other pathogens: CAV, MDV, NDV, etc.
Fowl Adenovirus Infection
Transmission:
* Vertical (egg)
* Horizontal (feco-oral route)
Diagnosis:
1. Serology,
2. Histopathology
3. Necropsy
4. PCR
Control:
1. vaccination
2. farm hygiene (proper disinfection)
3. start with ____-free flocks
Fowl Adenovirus Infection
