Bacterial INfections of Poultry Flashcards
Reminder - what are the AB categories?
A - Avoid
B - Restrict
C - Caution
D - Prudence
Which cat D Abs have a 0-day egg withdrawl ?
Narrow spec penicillins
Which cat C Abs have 0-day egg withdrawl ?
Macrolides, Pleuromutilins
What is collibacillosis partially or entirely caused by?
E.Coli (APEC - Avian Pathogenic E.Coli)
T/F Collibacillosis is the 3rd most common bacterial infection in poultry?
FALSE - 1st!
What are the sommon infections caused by APEC
infections caused by APEC in chickens are perihepatitis, airsacculitis, pericarditis,
egg peritonitis, salphingitis, coligranuloma, omphalitis, cellulitis, and osteomyelitis/arthritis; these are
commonly referred as avian colibacillosis
What predisp factors of APEC?
- Concurrent viral ro mycoplasma infection
- Immunosuppresisve or stressed conditions
What Outcomes of APEC?
High morbidity & mortality
- Production losses
- Carcass condemnations
- Food borne human infections
Describe pathogenesis of APEC?
Entry -> Colonises the mucosal sites without causing disease -> Presence of concurrent infections or
immunosuppression or stress -> Invades the mucosal layers and reach extra-intestinal organs -> multisystemic infections referred to as colibacillosis
Transmisssion of APEC?
- Egg transmission (some percentage vertical and fecal contamination of surface)
- Oral tracheal, caecal or oviduct contamination
- Direct or indirect contact with infected animals or free living birds
- Egg contmaination on breeder farms and hatcheries
How does transmission in hatcheries happen?
- Floor eggs set in different incubators
OR - Bottom of incubators
Descibre CS with Coliform Omphalitis/ Yolk sac infection
- Abdomen is distended and BV hyperaemic
- Necrosis, lysis and wetnjess of underlying skin = Mushy chicks or poults
- Swollen yolk sac with unabsorbed yolk and inflammatory fluid
- Yolk content putrefactive necrotic processes in the peritoneal cav
swollen head syndrome?
Acute to subacutee cellulitis involving êriorbital and adjacent subcut tissues of the head
- Upper resp viral infection aggravates dx
Salpingitis and/ or peritonitis consequences?
Inflammation of oviduct. = dec egg prod and sporadic mortality
describe Salpingitis and or peritonitis ?
- Ascending infection or through colisepticaemia?
- Egg peritonitis: accumulate of caseated exudate
- Abdominal laying and egg binding
CLS of E.coli infeciton?
- Resp distress
- Swollen abdo
- Lethargy
- Dec egg production
- D+
- SD
Diagnosis of E.Coli infection?
PM findings :
- Retained yolk sac
- Pericarditis
- Airsacculitis
- Peritonitis
- Coligranuloma
What isolation lab techinques for diagnosis of E.coli?
- Bacteriologicla culture (mac conkey agar)
- AM Sensitivity testing
What molecular diagnosing can we do?
- PCR
- Quantitative PCR (qPCR)
- Sequencing
Other differentials for peritonitis?
- Salmonellosis
- Pasteurellosis
- Enterococci
- Streptococci
other differentials for air sacculitis?
- Mycoplasma
- Chlamydiasis
Can u use amox for APEC tx?
AMOXICILLIN (15mg/kg bw for 3-5 days)
Withdrawal: meat and offal of chickens 1d ; Turkeys 5 d
-> Not authorised for use in laying birds producing eggs for human consumption and within 3 weeks of onset of laying
Can u use Colistin sulfate as tx of APEC for eggs?
75000 IU/kg for 3-5 d
Chickens and turkeys offal/meat: 1 d
Eggs: zero days
What else might we give for tx of APEC ?
Probiotics, prebiotics, vits, immune enhancersn anti-inflammatories
What Management procedures for prevention & control of colicobacillosis?
- Prevent faecal contamination
- Clear rodent droppings
- Give pelletised feed, clean or chlorinated water
- Sure good air and litter quality
What else can be done for control of colicobacillosis?
Vaccination & Bacterins?
Describe Mycoplasma Gallisepticum
Characterised by respiratory rales, coughing, nasal disC and conjunctivitis and frequent in turkeys, infraorbital sinusitis
Synonyms: Chronic Respiratory Dx
What mycoplasma species are important in avian medicine?
M. gallisepticum
M meleagridis
M.synoviae
they haemagglutinate erythrocytes from chickens and turkeys
Describe transmission of Mycoplasma G?
- Horizontal -> direct / indirect contact & fomites
- Vertical -> eggs laid by naturally infected hens (remain infected for life)
T/F spread of Mycoplasma is quite fast amongst other birds?
FALSE - quite slowW
What C/S of Mycoplasma gallisepticum?
- Sneezing, coughing, moist rales, breathing through open beak
- Reduced feed consumption & lost weight
- Egg prod decrease
- Conjunctivits
What pathological findings?
- Catarrhal exudates in nasal / paraN passages, trachea bronchi and air sacs
- Thickening of mucous membranes of affected tissue from infiltration with mononuclear cells and hyperplasia of the mucous glands
- Some pneumonia
- Conjuncitivitis, facial oedema & profuse tear secretion
Diagnosis for Mycoplasma G?
- CS and PME
- Isolation of agent
- Serology: ELISA (for prevalence ) & HI
- Molecular -> PCR; real-time PCR
Differentials for Mycoplasma G ?
- Newcastle disease
- Fowl cholera
- Infectious bronchitis
- E. coli infection
- Infectious coryza
(respiratory signs)
What options for TX of Mycoplasma G?
- Tylosin tartrate (egg WP 0 days)
- Tiamulin (egg WP 0 days)
- both WP for meat = 1 d
from day 1-5 admin ; WP day 6, slaughter on d7
Prevention of Mycoplasma G?
- Vaccination should be done in epidemic areas.
- Fresh parent stock free of the disease should be use in production.
- Good hygiene and management on the farm is important.
Mycoplasma Synoviae infection - describe ?
- Causes infectious synovitis affecting the joints and tendon sheaths producing exudative synovitis or bursitis.
- Subclin upper resp infection
Transmission Mycoplasma synoviae ?
- Horizontal via respiratory tract, Vertical transmission.
- Birds are infected for life and remain carriers.
- Air sac lesions when
combined with ND, IB or both
What clinical findings of Mycoplasma synoviae?
- Retarded growth, pale comb and lameness are the first signs seen.
- Feather becomes ruffled, comb shrinks or cyanotic.
- joint swelling and breast blisters.
- Egg production may drop to 30% as birds become listless, dehydrated and emaciated.
- greenish diarrhea.
- Joints are oedematous & thickened periarticular tissues
of the synovial membrane.
What pathological findings
- Creamy/grey exudate in synovial membranes
- Liver may be swollen and mottled green or dark red in colour
- Splenomegaly and renomegaly with pale and mottled kidney
- thymus and bursa of fabricius atrophied
Tx for Mycoplasma synoviae?
Tylosin Tartrate OR Tiamulin (DENAGARD)
Prevention of Mycoplasma synoviae?
- Vaccination should be done in epidemic areas.
- Fresh parent stock free of the disease should be use in production.
- Good hygiene and management on the farm is important.
What is Fowl Cholera?
It is an acute, contagious disease of domesticated and wild birds causing high mortality and morbidity.
Subacute, localised and chronic forms of the disease occur.
What synonyms for fowl cholera?
: Avian Cholera, Avian Pasteurellosis, Avian Haemorrhagic Septicemia
Aetiology of Fowl Cholera ?
Pasteurella Multocida
Describe the epidemiology of Pasteurella Multocida?
Present in most countries of the world.
Host: Turkey (mostly), Chicken, ducks, geese, companion birds.
Adult laying birds (>16week) are most affected but all are susceptible
Transmission of Fowl Cholera?
- Chronically infected birds &actely infected carcass
- Free flying birds
- Infected farm animals and rodents
- Excretions from mouth, nose, conjunctiva that contaminates feed
- Contaminated crates, feed bags, or equipment
- Flies and ticks can also transmit the organism
CLS of Fowl Cholera? (peracute / acute)
- In peracute and acute forms, death may be seen without premonitory signs
- Anorexia, cyanotic combs and wattles, catarrhal discharges from nostrils, mucoid discharge from the mouth
- There may be dehydration & yellowish or greenish D+
- Respiratory distress esp turkey
Fowl Cholera C/S in hronic form?
- Tracheal rales and dyspnea can be observed
- Swollen wattle, comb, sinuses, face, joints, footpad, sternal bursae
- Torticollis and Opisthotonus may result when the meninges,
middle ear or cranial bones are infected. - Faeces is watery and whitish initially,
then greenish/yellowish and mucoid later
PME findings ->
- Hepatomegaly with some coagulative necrosis
- Congestion, enlargement & dark coloration of liver, kidney & spleen
- Congestion lungs & pneumonia
- Ecchymotic haemorrhages in lungs, abdo fat and intestinal mucosa
PME findings (pt 2) ?
- Pinpoint necrotic areas on the muscles, proventriculus and serosa of intestines.
- Flaccid and hyperemic follicles
- Caseous exudates may be found around the hock joints, footpads, peritoneal cavity and oviduct
- Ova may be congested or ruptured.
Diagnosis of Fowl Cholera?
- CLS @ PM
- Culture isolation etc
- PCR
- Serology
- Presence of bipolar organism in heart blood or liver impression smear
DDx ?
- Mycoplasmosis
- Avian influenza
- NDV
for resp signs and vascular disturbances
TX for Fowl Cholera?
Depopulation thorough leaning and disinfection
- Sulphonamides (WP meat 1d)
- Phenoxypethylpenicillin or Phenocillin -> WP meat 2d; eggs 0 days
What to note about Sulphonamide use in layers?
Sulfa drugs should be used with
caution in breeders because of
potential toxicity and cannot be
used in hens laying eggs for human
consumption
Prevention & Control - fowl cholera?
- Carrier birds & animals should be prevnted from mixing with free flock
- Birds of different ages should not be reared together ‘all i, all out’
- Disinfection
- Vaccination
Describe Infectious Coryza
It is an acute respiratory disease of chickens characterised by nasal discharges, sneezing and swelling
of the face.
Synomys of infectious coryza ?
Roup, Contagious or Infectious Catarrh, cold
What aetiology of infectious corya?
Avibacterium paragallinarum
Epidemiology fo infectious coryza?
Public Health Importance: No public health significance.
Epidemiology: The disease occurs worldwide.
Host: Chicken is the only natural host and they are infected with clinical signs.
Age susceptible: All ages but less severe in chicks
Economic importance of Infectious Coryza?
- Increase number of culls in growing chickens
- Reduced egg production in layers especially in multi-age farms (carrier birds implicated)
Transmission of Infectious Coryza?
HORIZONTAL
- The main sources of infection are clinically infected birds, chronic or healthy carrier birds
- Bird to bird contact
- Through aerosol coughed out into air or water.
- Spread between batteries with nipple drinkers occurs more slowly
Clinical signs Fowl choelra?
- First signs: serous to mucoid nasal discharge, facial oedema and marked conjunctivitis with closed
eyes. - Swollen wattles and difficult breathing or rales (if lower repsiratory tract is involved)
- D+
PME findings
- Chicken affected have catarrhal to fibrinopurulent exudates in the nasal passages, infraorbital
sinuses, conjunctiva and trachea. - Lungs and airsacs are only affected in chronic complicated cases.
- Swollen periorbital region
Diagnosis of fowl cholera?
- Clinical and postmortem findings
- Isolation and identification of causative agent (Infraorbital wash)
- PCR
- Serology –ELISA, HI tests
- Blood Biochemistry
Differentials list?
- Chronic respiratory disease
- Chronic fowl cholera
- Fowl pox
- Swollen head syndrome
- Vitamin A deficiency
Tx for Fowl Cholera?
Combination of Sulphonamides & Trimethoprim
Sulph WP meat 1d
Amox (not in birds laying for consumption)
Tylosin Tartare
Prevention & Control for fowl cholera
- Sanitise drinking water and by daily fogging can reduce the duration and severity of clinical signs.
- Vaccinate birds in epidemic areas.
- Recovered birds possess varying degree of immunity to re-exposure.
- All in and all out programme
Describe Erysepelas
Erysipelas is a bacterial disease in poultry caused by Erysipelothrix
rhusiopathiae.
HOST: Turkeys, chickens & other
ZOONOTIC dx : through cuts @ abrasions
what kind of pathogen is eryseplas rhusiopathiae?
gram-positive, rod-shaped bacterium that can survive in soil and
organic matter for extended periods.
It is hardy and resistant to environmental stressors, making it a persistent pathogen on farms.
`Transmission?
HORIONTAL
- Through soil, feed, water
- Direct contat , vectors like rodents and insects
- Cuts or abrasions provide an entry point
CLS of Erysepelas ? Peracute?
death
CLS of Erysepelas ? Acute form?
Depression and Lethargy
Ruffled Feathers and Loss of Appetite
Swollen Wattles and Cyanosis
Diarrhea
Egg Production Drops
CLS of Erysepelas ? Chronic form?
Lameness and Joint Swelling
Weight Loss and Poor Growth
PME LEsions?
Subcutaneous hemorrhages and swelling, especially around the comb, wattles, and face.
Enlargement of the spleen and liver, with petechial (pinpoint) hemorrhages on these organs.
I
n some cases, birds may have endocarditis (infection of the heart valves), which can lead to sudden
death.
Fibrin deposits in the heart, liver, and air sacs are commonly observed in acute cases.
Diagnosis of Erysepelas
- Bacterial isolation
- Histopath
- PCR
Differentials for erysepelas?
Fowl cholera & avian influenza (cyanosis)
Colibacillosis & salmonellosis (hepatomegaly, splenomegay)
Tx for Erysipelas?
- Penicillin or erythromycin and tetraC
Phenocillin WP meat 2d egg 0d
what other tx for erysepelas?
Supportive Care: easy access to food and water, warm, stress-free environment to improve recovery.
Prevention and Control
Vaccination: killed vaccine effective in preventing outbreaks, especially in endemic areas.
Biosecurity Measures: Strict biosecurity, Rodent control,
Proper sanitation and disinfection, Isolating and culling infected birds.
Environmental Management: Maintain clean, dry bedding and
regularly remove waste to reduce bacterial load in the environment.
Describe zoonotic risk of erysipelas
Erysipelas is a zoonotic disease, humans handling infected birds or contaminated materials are at risk
of contracting erysipeloid, a skin infection characterised by red, swollen lesions at the site of infection.
Economic impat of Erysipelas
High mortality rates.
Reduced productivity in laying hens.
Costs associated with treatment, vaccination, and biosecurity measures.
