selected bacterial and mycotic infections of poultry bacterial and mycotic infections of poultry...

Selected bacterial and Selected bacterial and mycotic infections of mycotic infections of

poultrypoultry Summer term 2010Summer term 2010

Clostridia Clostridia ClostridiaClostridia are large, Gram positive, rod-shaped, toxin producing are large, Gram positive, rod-shaped, toxin producing

bacteria than are anaerobic and can produce endospores as a bacteria than are anaerobic and can produce endospores as a means of survial. means of survial.

The are ubiquitous worldwide, being found in The are ubiquitous worldwide, being found in soil, dust, animals soil, dust, animals and insect larvae. and insect larvae.

The The predisposition factorspredisposition factors include management, nutrition and include management, nutrition and environmental conditions. environmental conditions.

Increasing restriction of the use in-feed antimicrobials in Europe Increasing restriction of the use in-feed antimicrobials in Europe and other regions has changes the status of and other regions has changes the status of C. perfringens-C. perfringens- associated necrotic enteritisassociated necrotic enteritis in poultry, especially in broilers. in poultry, especially in broilers.

Necrotic EnteritisNecrotic Enteritis

Necrotic EnteritisNecrotic EnteritisAn acute or chronic enterotoxemia seen in chickens, An acute or chronic enterotoxemia seen in chickens, turkeys and ducks worldwide, caused by turkeys and ducks worldwide, caused by Clostridium Clostridium perfringensperfringens and characterised by a fibrino-necrotic and characterised by a fibrino-necrotic enteritis, usually of the mid- small intestine. enteritis, usually of the mid- small intestine. Mortality may be 5-50%, usually around 10%. Infection Mortality may be 5-50%, usually around 10%. Infection occurs by faecal-oral transmission. occurs by faecal-oral transmission. Spores of the causative organism are highly resistant. Spores of the causative organism are highly resistant. Predisposing factorsPredisposing factors include coccidiosis/coccidiasis, diet include coccidiosis/coccidiasis, diet (high protein), in ducks possibly heavy strains, high (high protein), in ducks possibly heavy strains, high viscosity diets (often associated with high rye and wheat viscosity diets (often associated with high rye and wheat inclusions in the diet), contaminated feed and/or water, inclusions in the diet), contaminated feed and/or water, other debilitating diseases. other debilitating diseases.

Toxinotypes of Toxinotypes of Clostridium Clostridium perfringensperfringens

Typ Main toxineAlfa (α) Beta (β) Epsilon (ε) Iota (ι)

A produce

B produce produce produce

C produce produce

D produce produce

E produce produce


SignsSigns Depression. Depression. Ruffled feathers. Ruffled feathers. Inappetance. Inappetance. Closed eyes. Closed eyes. Immobility. Immobility. Dark coloured diarrhoea. Dark coloured diarrhoea.


Necrotic enteritis appears suddenly in the affected flock. Necrotic enteritis appears suddenly in the affected flock.

Apparently healthy birds may become acutely depressed Apparently healthy birds may become acutely depressed

and die within hours. Mortality is usually between two and die within hours. Mortality is usually between two

and ten percent, but may be as high as thirty percent in and ten percent, but may be as high as thirty percent in

severe outbreaks. severe outbreaks. Losses due to reduced growth and Losses due to reduced growth and

feed conversion may be more costly than flock mortalityfeed conversion may be more costly than flock mortality..

Necrotic EnteritisNecrotic EnteritisPost-mortem lesionsPost-mortem lesions Small intestine (usually middle to distal) Small intestine (usually middle to distal)

thickened and distended. thickened and distended. Intestinal mucosa with diptheritic membrane. Intestinal mucosa with diptheritic membrane. Intestinal contents may be dark brown with Intestinal contents may be dark brown with

necrotic material. necrotic material. Reflux of bile-stained liquid in the crop if upper Reflux of bile-stained liquid in the crop if upper

small intestine affected. small intestine affected. Affected birds tend to be dehydrated and to Affected birds tend to be dehydrated and to

undergo rapid putrefaction. undergo rapid putrefaction.

Cholangiohepatitis


DiagnosisDiagnosisA presumptive diagnosis may be made A presumptive diagnosis may be made based on flock history and gross lesions based on flock history and gross lesions Confirmation is on the observation of Confirmation is on the observation of abundant rods in smears from affected abundant rods in smears from affected tissues and a good response to specific tissues and a good response to specific medication, usually in less than 48 hours. medication, usually in less than 48 hours.

Lesion score of NELesion score of NE


Diagnosis specificDiagnosis specificbacteriologybacteriology

- - examination for examination for C. perfringensC. perfringens on blood agar plates on blood agar plates (anaerobic)(anaerobic)

histologyhistology- - finding of aggregation of large Gram positive rod shaped finding of aggregation of large Gram positive rod shaped

bacteria sorrounded by necrotic tissue bacteria sorrounded by necrotic tissue

examination for coccidiaexamination for coccidia

Necrotic EnteritisNecrotic EnteritisPreventionPrevention

Penicillin in feed is preventive, high levels of Penicillin in feed is preventive, high levels of most growth promotors and normal levels of most growth promotors and normal levels of ionophore anticoccidials also help.ionophore anticoccidials also help. Probiotics may limit multiplication of bacteria and Probiotics may limit multiplication of bacteria and toxin production. In many countries local toxin production. In many countries local regulations or market conditions prevent the regulations or market conditions prevent the routine use of many of these options. routine use of many of these options.

BotulismBotulism

A condition of chickens, turkeys, ducks and other waterfowl A condition of chickens, turkeys, ducks and other waterfowl occurring worldwide and caused by a bacterial toxin produced by occurring worldwide and caused by a bacterial toxin produced by Clostridium botulinumClostridium botulinum mainly types A / C. mainly types A / C.

The toxin is produced in decaying animal (usually carcases) and The toxin is produced in decaying animal (usually carcases) and plant waste, and toxin-containing material (pond-mud, carcases, plant waste, and toxin-containing material (pond-mud, carcases, maggots) is consumed by the birds. maggots) is consumed by the birds.

Toxin may also be produced by the bacteria in the caecum. Toxin may also be produced by the bacteria in the caecum. Morbidity is usually low but mortality is high. Morbidity is usually low but mortality is high.

The toxin and bacterial spores are relatively stable and may survive The toxin and bacterial spores are relatively stable and may survive for some time in the environment. for some time in the environment.

BotulismBotulism

SignsSigns Nervous signs, weakness, progressive Nervous signs, weakness, progressive

flaccid paralysis of legs, wings then neck, flaccid paralysis of legs, wings then neck, then sudden death. then sudden death.

Affected broilers tend to settle with eyes Affected broilers tend to settle with eyes closed when not disturbed. closed when not disturbed.

A soiled beak, because it rests on the A soiled beak, because it rests on the litter, is also quite typical. litter, is also quite typical.

BotulismBotulism

Post-mortem lesionsPost-mortem lesions Possibly no significant lesions. Possibly no significant lesions.

Mild enteritis if has been affected for some time. Mild enteritis if has been affected for some time.

Feathers may be easily pulled (chicken only). Feathers may be easily pulled (chicken only).

Maggots or putrid ingesta may be found in the crop. Maggots or putrid ingesta may be found in the crop.

BotulismBotulism

PreventionPrevention

Preventing access to toxin, suspect food and stagnant Preventing access to toxin, suspect food and stagnant

ponds, especially in hot weather. The single most ponds, especially in hot weather. The single most important measure is careful pick-up and removal of all important measure is careful pick-up and removal of all dead birds on a daily basis. This will reduce the risk of dead birds on a daily basis. This will reduce the risk of botulism in the poultry. botulism in the poultry.

OrganismOrganism

Clostridium botulinumClostridium botulinum Gram positiveGram positive Obligate anaerobic bacillusObligate anaerobic bacillus SporesSpores

• UbiquitousUbiquitous• Resistant to heat, light, drying and radiationResistant to heat, light, drying and radiation• Specific conditions for germinationSpecific conditions for germination

Anaerobic conditionsAnaerobic conditions Warmth (10-50Warmth (10-50ooC)C) Mild alkalinityMild alkalinity

NeurotoxinsNeurotoxins

Seven different typesSeven different types: A through G: A through G Different types affect different speciesDifferent types affect different species All cause flaccid paralysis All cause flaccid paralysis Only a few nanograms can cause illnessOnly a few nanograms can cause illness Binds neuromuscular junctionsBinds neuromuscular junctions

ToxinToxin: Destroyed by boiling: Destroyed by boiling SporesSpores: Higher temperatures to be : Higher temperatures to be

inactivatedinactivated

Birds and Poultry:Birds and Poultry:Clinical SignsClinical Signs

Occurs 12-48 hours after ingestionOccurs 12-48 hours after ingestion Droopy headDroopy head DrowsyDrowsy Wing and leg paralysisWing and leg paralysis

Unable to hold their head upUnable to hold their head up Unable to use their wings or legsUnable to use their wings or legs

Eyelid paralysisEyelid paralysis

Birds and PoultryBirds and Poultry

““Limber neck”Limber neck” Types C and ETypes C and E Good sentinel speciesGood sentinel species Sources:Sources:

Decomposed vegetation or invertebratesDecomposed vegetation or invertebrates Ingest toxin or invertebrates with toxinIngest toxin or invertebrates with toxin Contaminated feed or water of chickensContaminated feed or water of chickens

StaphylococcosisStaphylococcosisAll avian species appear to be susceptible to All avian species appear to be susceptible to staphylococcosis, which is common worldwide staphylococcosis, which is common worldwide wherever poultry are reared. wherever poultry are reared. Staphylococcus aureusStaphylococcus aureus is usually the causative is usually the causative agent, but there is increasing evidence that other agent, but there is increasing evidence that other StaphylococcusStaphylococcus species may also be involved species may also be involved (coagulase-positive and coagulase-negative).(coagulase-positive and coagulase-negative).

StaphylococcosisStaphylococcosis

Staphylococci are associated with a wide variety Staphylococci are associated with a wide variety of diseases in the chicken and turkey, and in of diseases in the chicken and turkey, and in other avian species.other avian species.These include These include septicaemia, arthritis and septicaemia, arthritis and tendosynovitis, bacterial chondronecrosis tendosynovitis, bacterial chondronecrosis and osteomyelitis, gangrenous dermatitis, and osteomyelitis, gangrenous dermatitis, yolk sac infection, subdermal abscesses yolk sac infection, subdermal abscesses (bumble foot), comb necrosis and often with (bumble foot), comb necrosis and often with cellulitis, endocarditis and granulomas.cellulitis, endocarditis and granulomas.

StaphylococciStaphylococciStaphylococcus aureusStaphylococcus aureus coagulase-positivecoagulase-positive coagulase-negativecoagulase-negativeThe disease condition can vary depending on The disease condition can vary depending on

where and how the bacteria enter the host; where and how the bacteria enter the host; infections have been reported in the bones, infections have been reported in the bones, joints, tendon sheaths, skin, sternal bursa, navel, joints, tendon sheaths, skin, sternal bursa, navel, yolk sac, liver, lungs, and eyelids. yolk sac, liver, lungs, and eyelids. Septicemic Septicemic infectioninfection has also been seen in laying chickens, has also been seen in laying chickens, with death occurring very quickly. with death occurring very quickly.

StaphylococciStaphylococci

StaphylococciStaphylococcifacultative anaerobes, catalase –positive facultative anaerobes, catalase –positive and grow readily on blood agar. and grow readily on blood agar. poultry strain of poultry strain of S. aureus S. aureus usually show usually show αα- or - or δδ- hemolysis.- hemolysis.


Differential diagnosis:Differential diagnosis:- E. coliE. coli- salmonellassalmonellas- Pasteurella multocidaPasteurella multocida- Mycoplasma synoviae Mycoplasma synoviae - reovirusesreoviruses

StaphylococcosisStaphylococcosisControlControlBird in early stages of infection and disease may respond Bird in early stages of infection and disease may respond

to treatment but those with well-established lesion are to treatment but those with well-established lesion are unlikely to respond.unlikely to respond.

S. aureusS. aureus is inherently a rather resistatn organismus. is inherently a rather resistatn organismus. Antimicrobial sensitivity testing.Antimicrobial sensitivity testing.

Avian TuberculosisAvian Tuberculosis

A bacterial infection, caused by A bacterial infection, caused by Mycobacterium aviumMycobacterium avium, ,

of poultry, game birds, cage birds etc. Morbidity and of poultry, game birds, cage birds etc. Morbidity and

mortality are high. Transmission is via faecal excretion, mortality are high. Transmission is via faecal excretion,

ingestion, inhalation, offal and fomites. The disease has ingestion, inhalation, offal and fomites. The disease has

a slow course through a flock. The bacterium resists a slow course through a flock. The bacterium resists

heat, cold, water, dryness, pH changes and many heat, cold, water, dryness, pH changes and many

disinfectants.disinfectants.


SignsSigns Severe loss of weight with no loss of appetite. Severe loss of weight with no loss of appetite.

Pale comb. Pale comb.

Diarrhoea. Diarrhoea.

Lameness. Lameness.

Sporadic deaths. Sporadic deaths.


Post - mortem lesionsPost - mortem lesions

Emaciation. Emaciation.

Grey to yellow nodules attached to intestine. Grey to yellow nodules attached to intestine.

Granulomas in liver, spleen and many other Granulomas in liver, spleen and many other

tissues, even bone marrow. tissues, even bone marrow.

Tubercular nodules in bone marrow.

Mycobacterium avium

Positive tuberculin test

Positive rapid blood agglutination .

Campylobacter Infection Campylobacter Infection Campylobacters are a significant cause of Campylobacters are a significant cause of enteritis in man. Infected poultry are a potential enteritis in man. Infected poultry are a potential reservoir of this zoonosis. reservoir of this zoonosis. Campylobacter jejuniCampylobacter jejuni is the commonest species is the commonest species found in poultry. All campylobacters are delicate found in poultry. All campylobacters are delicate organisms that survive for relatively short organisms that survive for relatively short periods outside the host unless protected by periods outside the host unless protected by organic material, biofilm or engulfed by protozoa. organic material, biofilm or engulfed by protozoa.

Campylobacter jejuniCampylobacter jejuni Leading cause of bacterial diarrheaLeading cause of bacterial diarrhea 2.4 million people each year2.4 million people each year

Children under 5 years oldChildren under 5 years old Young adults (ages 15-29)Young adults (ages 15-29)

Very few deathsVery few deaths Can lead to Guillain-Barré SyndromeCan lead to Guillain-Barré Syndrome

Leading cause of acute paralysis Leading cause of acute paralysis Develops 2-4 weeks after Develops 2-4 weeks after CampylobacterCampylobacter infection infection

(after diarrheal signs disappear)(after diarrheal signs disappear)

CampylobacteriosisCampylobacteriosis Sources Sources

Raw or undercooked poultryRaw or undercooked poultry Non-chlorinated waterNon-chlorinated water Raw milkRaw milk Infected animal or human fecesInfected animal or human feces

• Poultry, cattle, puppies, kittens, pet birdsPoultry, cattle, puppies, kittens, pet birds Clinical signsClinical signs in humans in humans

Diarrhea, abdominal cramps, Diarrhea, abdominal cramps, fever, nauseafever, nausea

Duration: 2-5 daysDuration: 2-5 days

Campylobacter InfectionCampylobacter Infection

DiagnosisDiagnosis

Isolation of the organism from caecal contents, cloacal swabs Isolation of the organism from caecal contents, cloacal swabs

or composite faeces. The organism is sensitive to air so swabs or composite faeces. The organism is sensitive to air so swabs

should be collected into transport medium and other samples should be collected into transport medium and other samples

placed in airtight containers with minimal airspace. Samples placed in airtight containers with minimal airspace. Samples

should be tested as quickly as possible after collection.should be tested as quickly as possible after collection.

Campylobacter InfectionCampylobacter InfectionPreventionPrevention

In principle, housed poultry can be maintained free of In principle, housed poultry can be maintained free of

CampylobacterCampylobacter infection by consistent application of excellent infection by consistent application of excellent

biosecurity. Key aspects of this include effective sanitation of biosecurity. Key aspects of this include effective sanitation of

drinking water, sourcing of water from high quality supplies, drinking water, sourcing of water from high quality supplies,

avoidance of contact with pets and other farmed species, good avoidance of contact with pets and other farmed species, good

hand hygiene by stockmen, and changing of overalls and boots hand hygiene by stockmen, and changing of overalls and boots

on entering bird areas.on entering bird areas.

SalmonellosisSalmonellosis

Gram negative bacteriaGram negative bacteria Many serotypes can cause diseaseMany serotypes can cause disease S.S. enteritidisenteritidis and and typhimuriumtyphimurium

• 41% of all human cases 41% of all human cases • Most common species in U.S. Most common species in U.S.

1.4 million cases annually1.4 million cases annually 580 deaths580 deaths

SalmonellosisSalmonellosis SourcesSources

Raw poultry and eggsRaw poultry and eggs Raw milkRaw milk Raw beefRaw beef Unwashed fruit, alfalfa sproutsUnwashed fruit, alfalfa sprouts Reptile pets: Snakes, turtles, lizardsReptile pets: Snakes, turtles, lizards

SignsSigns Onset: 12-72 hours Onset: 12-72 hours Diarrhea, fever, crampsDiarrhea, fever, cramps Duration: 4-7 daysDuration: 4-7 days

On Farm StrategiesOn Farm Strategies

Testing and removal for Testing and removal for SalmonellaSalmonella Serologic, fecal culture, hide cultureSerologic, fecal culture, hide culture

Vaccinating Vaccinating Many serotypesMany serotypes Varying effectivenessVarying effectiveness

Minimize rodents, wild birdsMinimize rodents, wild birds Isolation of new animalsIsolation of new animals

Avian chlamydophilosisAvian chlamydophilosis

TermsTermsPsittacosisPsittacosis – first recognized in parrots – first recognized in parrotsOrnithosisOrnithosis – describe disease in other birds, – describe disease in other birds,

including poultryincluding poultry

The OrganismThe Organism

Chlamydophila psittaciChlamydophila psittaci Obligate intracellular bacteriaObligate intracellular bacteria Elementary body Elementary body

InfectiousInfectious Survive for months in environmentSurvive for months in environment

Reticulate body Reticulate body Non-infectiousNon-infectious

New Taxonomic ClassificationNew Taxonomic Classification Genus Genus ChlamydiaChlamydia

C. trachomatisC. trachomatis C. muridarumC. muridarum C. suisC. suis

Genus Genus ChlamydophilaChlamydophila C. abortusC. abortus C. felisC. felis C. pecorumC. pecorum C. pneumoniaeC. pneumoniae C. caviaeC. caviae C. psittaciC. psittaci

The OrganismThe Organism

Resistant to drying Resistant to drying Remains infectious for monthsRemains infectious for months Remains viable on surfaces for 2-3 weeksRemains viable on surfaces for 2-3 weeks Survives in turkey carcass for >1 yr. Survives in turkey carcass for >1 yr.

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HistoryHistory 18791879

First recognized human outbreakFirst recognized human outbreak 7 people in contact with sick parrots7 people in contact with sick parrots

1929-19301929-1930 750 human cases750 human cases

• 20% mortality 20% mortality Large scale importation of Large scale importation of

infected birds from Argentinainfected birds from Argentina 19351935

Wild psittacines in AustraliaWild psittacines in Australia

Populations at RiskPopulations at Risk Lab workersLab workers VeterinariansVeterinarians Avian quarantine Avian quarantine

workersworkers Zoo workersZoo workers FarmersFarmers Pregnant womenPregnant women

Bird fanciers Bird fanciers (pigeon fanciers too)(pigeon fanciers too)

Bird ownersBird owners Pet shop employeesPet shop employees Poultry slaughter and Poultry slaughter and

processing workersprocessing workers Wildlife rehab workersWildlife rehab workers

Transmission to HumansTransmission to Humans Inhalation Inhalation

Dried infective droppingsDried infective droppings Secretions or dust from Secretions or dust from

feathersfeathers Mouth-to-beakMouth-to-beak Direct contactDirect contact

Handling plumage or tissues of Handling plumage or tissues of infected birdsinfected birds

Person-to-person transmissionPerson-to-person transmission Not provenNot proven Venereal transmission reportedVenereal transmission reported

Clinical SignsClinical Signs

May also seeMay also see Myocarditis, endocarditis Myocarditis, endocarditis Arthritis, lethargy, hepatitis, epistaxisArthritis, lethargy, hepatitis, epistaxis Placentitis, fetal deathPlacentitis, fetal death Encephalitis, jaundice, respiratory failure Encephalitis, jaundice, respiratory failure Thrombocytopenia, coma, arthralgiaThrombocytopenia, coma, arthralgia

Disease in HumansDisease in HumansPsittacosisPsittacosis

Human Disease: PsittacosisHuman Disease: Psittacosis

Incubation period: 1-4 weeksIncubation period: 1-4 weeks RangeRange

Inapparent infectionInapparent infection Systemic infection with pneumoniaSystemic infection with pneumonia

• Pneumonia 30-60 years of agePneumonia 30-60 years of age

Common signs – abrupt onsetCommon signs – abrupt onset Fever, chills, headache, malaise, myalgia, Fever, chills, headache, malaise, myalgia,

sore throat, cough, dyspnea, splenomegaly, sore throat, cough, dyspnea, splenomegaly, rashrash

45 year old male, rail station worker with Chlamydial pneumonia

DiagnosisDiagnosis

Confirmed caseConfirmed case Clinical signs + laboratory resultsClinical signs + laboratory results

• CultureCulture• 4-fold rise in titer4-fold rise in titer• IgM detected by MIFIgM detected by MIF

Probable caseProbable case Linked epidemiologically to confirmed case of Linked epidemiologically to confirmed case of

PsittacosisPsittacosis Single titer Single titer ≥≥1:321:32

Differential DiagnosisDifferential Diagnosis

Coxiella burnetiiCoxiella burnetii (Q fever) (Q fever) LegionellaLegionella Chlamydia pneumoniaeChlamydia pneumoniae Mycoplasma pneumoniaeMycoplasma pneumoniae InfluenzaInfluenza TularemiaTularemia

Treatment and PrognosisTreatment and Prognosis

With treatmentWith treatment 1-5% case-fatality rate 1-5% case-fatality rate Tetracyclines are drug of choiceTetracyclines are drug of choice Remission of symptoms Remission of symptoms

• Usually in 48-72 hoursUsually in 48-72 hours Relapse possibleRelapse possible

Without treatmentWithout treatment May resolve in few weeks-monthsMay resolve in few weeks-months 10-40% case-fatality rate10-40% case-fatality rate

Avian Species AffectedAvian Species Affected

Isolated from over 100 avian species Isolated from over 100 avian species PsittacinesPsittacines

• Especially cockatiels and parakeetsEspecially cockatiels and parakeets Egrets, gulls, ratitesEgrets, gulls, ratites Pigeons, doves, mynah birds, sparrowsPigeons, doves, mynah birds, sparrows Turkeys, ducksTurkeys, ducks

• Rarely chickensRarely chickens

Clinical SignsClinical Signsin Turkey, Duck & Pigeonin Turkey, Duck & Pigeon

Depression Depression Ruffled feathers Ruffled feathers Weakness Weakness Inappetence Inappetence Nasal discharge Nasal discharge Respiratory distress Respiratory distress

Yellow-green diarrhea Yellow-green diarrhea ConjunctivitisConjunctivitis Decreased egg Decreased egg

productionproduction Ataxia-pigeonsAtaxia-pigeons Trembling-ducksTrembling-ducks

DiagnosisDiagnosis

Diagnosis difficultDiagnosis difficult Case definitionsCase definitions

Confirmed, probable, suspectConfirmed, probable, suspect Single test may not be adequateSingle test may not be adequate

Combination testing recommendedCombination testing recommended Proper sample collection techniques Proper sample collection techniques

critical for accurate resultscritical for accurate results Consult an experienced avian veterinarianConsult an experienced avian veterinarian

DiagnosisDiagnosis

Pathologic diagnosisPathologic diagnosis CultureCulture Antibody testsAntibody tests

CF, EBACF, EBA Antigen TestsAntigen Tests ELISA, IFA, PCRELISA, IFA, PCR RIMRIM

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AspergillosisAspergillosis

A fungal infectious disease, caused A fungal infectious disease, caused

by by Aspergillus fumigatusAspergillus fumigatus, in which the , in which the

typical sign is gasping for breath, typical sign is gasping for breath,

especially in young chicks. especially in young chicks.

Sometimes the same organism Sometimes the same organism

causes eye lesions or chronic lesions causes eye lesions or chronic lesions

in older birds. in older birds.


It affects chickens, turkeys, ducks, penguins, game It affects chickens, turkeys, ducks, penguins, game birds, waterfowl, etc, worldwide. birds, waterfowl, etc, worldwide.

The infection has an incubation period of 2-5 days. The infection has an incubation period of 2-5 days.

Morbidity is usually low, but may be as high as 12%. Morbidity is usually low, but may be as high as 12%.

Mortality among young affected birds is 5-50%. Mortality among young affected birds is 5-50%. Transmission is by Transmission is by inhalation exposureinhalation exposure to an to an environment with a high spore count; there is usually environment with a high spore count; there is usually little bird-to-bird transmission. Spores are highly resistant little bird-to-bird transmission. Spores are highly resistant to disinfectants. to disinfectants.

AspergillosisAspergillosisSignsSigns Acute formAcute form::

Inappetance. Inappetance. Weakness. Weakness. Silent gasping. Silent gasping. Rapid breathing. Rapid breathing. Thirst. Thirst. Drowsiness. Drowsiness. Nervous signs (rare). Nervous signs (rare).

Chronic FormsChronic Forms:: Ocular discharge (ocular form only). Ocular discharge (ocular form only). Wasting. Wasting.


Post-mortem lesionsPost-mortem lesions

Yellow to grey nodules or plaques in lungs, air sacs, trachea, Yellow to grey nodules or plaques in lungs, air sacs, trachea,

plaques in peritoneal cavity, may have greenish surface. plaques in peritoneal cavity, may have greenish surface.

Conjunctivitis/keratitis. Conjunctivitis/keratitis.

Brain lesions may be seen in some birds with nervous signs. Brain lesions may be seen in some birds with nervous signs.

Multiple nudules in the liver of 3 weeks old poult, due to aspergillosis.

Mycotic granuloma in cerebelum.

AspergillosisAspergillosisDiagnosisDiagnosis

This is usually based on the signs and lesions and This is usually based on the signs and lesions and microscopic examination for the fungus, preferably after microscopic examination for the fungus, preferably after digestion in 10% potassium hydroxide. digestion in 10% potassium hydroxide. It may be confirmed by It may be confirmed by isolation of the fungusisolation of the fungus, typically , typically by putting small pieces of affected tissue on Sabouraud by putting small pieces of affected tissue on Sabouraud agar. Growth occurs in 24-48 hours and colonies are agar. Growth occurs in 24-48 hours and colonies are powdery green/blue in appearance. powdery green/blue in appearance. Differentiate from excessive exposure to formalin or Differentiate from excessive exposure to formalin or vaccinal reactions in day olds and from heat stress in vaccinal reactions in day olds and from heat stress in older birds. older birds.

Aspergillosis Aspergillosis

TreatmentTreatmentUsually none. Environmental spraying with effective Usually none. Environmental spraying with effective antifungal antiseptic may help reduce challenge. antifungal antiseptic may help reduce challenge. Amphotericin B and Nystatin have been used in high-Amphotericin B and Nystatin have been used in high-value birdsvalue birds. .

PreventionPreventionDry, good quality litter and feed, hygiene.Dry, good quality litter and feed, hygiene.

selected bacterial and mycotic infections of poultry bacterial and mycotic infections of poultry...

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