3/2/2017

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Common diseases of backyard chickens, pathology and diagnostics

Aslı Mete, DVM, PhD, Diplomate ACVP

California Animal Health & Food Safety (CAHFS) Laboratory System

Todays talk:

CAHFS: the CA diagnostic laboratory system

Chicken necropsy procedures

Common diseases of chickens in backyard flocks

CAHFS Laboratory System

UC Davis CDFACA Department of Food & Agriculture

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CAHFS Laboratory System

Davis

Turlock

Tulare

San Bernardino

AVIAN, LIVESTOCK, HORSE

AVIAN

AVIAN, LIVESTOCK, HORSE

AVIAN, LIVESTOCK, HORSE

CAHFS Mission

PublicHealth

New Knowledge

Equine Health

Food SafetyHealth 

ManagementSurveillance

CAHFS Mission – backyard flocks

Public Health New Knowledge

Food Safety

Health Management

Surveillance

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Photo creditsAAAP  (contributions of all invaluable avian pathologists)

Dr. Dan Shaw’s “Necropsy procedure for game birds”

CAHFS necropsy cases, techs

ResourcesFARAD.org – Food Animal Residue Avoidance Bank 

AMDUCA – Extra label Drug Use Algorithm

UC EXTENSION ‐ http://ucanr.edu/sites/poultry/?search=yes

CDFA

Backyard Flocks (BYF)

Chickens, turkeys, waterfowl, game birds

<1000 birds

Food source, pet, hobby

Deanne de Silva

The ‘BYF Program’

CDFA – CAHFS partnership

Surveillance:    Exotic Newcastle Disease (END)

Highly Pathogenic Avian Influenza (HPAI)*

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HPAI

Sick or dead chicken?

Pathologist on duty performs necropsy

Swabs for HPAI/ENDAssigns tests: histopathology,bacteriology, virology, toxicology, serology

Findings reported by e‐mail/fax/mail

Live bird testing

Immunology ‐ Serology

Bacterial cultures, PCR – swabs

Toxicology – suspected toxin or surveillance Egg, soil, water, feed, blood etc.

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Choana /trachea swabs

Postmortem diagnostics Highly advantageous, effective

Necessary if multiple birds are dying/dead 

If sending – fridge up to a week! After that: freezeWet feathers to cool down fast

Necropsy/Pathology

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Histopathology

Necropsy

External exam: feathers, signs of 

trauma, ocular/nasal discharge

Necropsy

WET completely – soap helps!

Dander/healthPracticality 

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Necropsy ‐ ‘Normal’ vs ‘Not’

‘Normal’  vs  ‘Not’

Could be significant, or, incidental

‘Normal’  vs  ‘Not’

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‘Normal’         ?  ‘Not’

Necropsy

‘Normal’

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‘Normal’Laying hen

‘Normal’

Infectious60%

Non-Inf27%

Unknown13%

Overview of diagnoses 

n= 1301 chickens

Mete et  al., Avian Dis, 2013

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Causes of mortality in Northern CA: 2007‐2012

Bacterial23%

Viral30%

Fungal1.5%

Parasitic5%

Metabolic11%

Toxic 1%

Neoplastic 9%

Developmental 1%

Trauma 3%

Miscellaneous 2%Unknown

13%

n=1301

Conclusions

Most common etiologies: 

1. Marek’s disease 

2. Salpingitis, peritonitis

3. Carcinomatosis

4. Liver hemorrhagic syndrome

Zoonoses: 2% incidence

Mycobacteriosis, 

Salmonellosis, 

Listeriosis, 

Baylisascaris sp.

Common diseases of backyard flocks (chickens) and diagnostics

Respiratory system

Digestive system

Reproductive system

Metabolic / Toxic

Integument

Nervous system

Lymphoproliferative diseases

Clinical signs:

• many times “found dead”

• ADR ‐ “ain’t doin’ right”

• on and off, not easy to see!

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Respiratory system signsSinuses, trachea, lungs, air sacs 

Swollen sinuses

Ocular / nasal discharge

Open mouth breathing

Difficulty to breath

Coughing /sneezing / wheezing

‘Bubbly’ eyes

Respiratory system diseases

Avian Influenza (AI)

Exotic Newcastle Disease (END)

Infectious Laryngotracheitis (ILT)

Pox virus

Infectious Bronchitis Virus (IBV)

Mycoplasma gallisepticum

Mycoplasma synoviae

Pasteurella multocida

Avibacterium paragallinarum

Chlamydia psittaci (turkeys)

Viral Bacterial

Parasitic Fungal

Trichomonas gallinae

GapewormAspergillus spp. 

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Mycoplasma spp. – MG/MS 

P. multocida ‐ Fowl Cholera

(Avibacterium paragallinarum)

Sinusitis

MG and Fowl Cholera

Air sacculitisAir sacs

TracheaHealthy

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END

ILT

HPAI

Tracheitisacute

d1614960

Dr. Dan Famini

Tracheitissubacute/chronic

d1614960

DDx: ILT, Pox v. (wet pox), END!,  Trichomonas

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Trichomoniasis

Aspergillosis

Healthy

LungsPneumonia, cholera

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Neoplasia

Squamous cell carcinoma

Diagnosis of respiratory diseases

Histopathology, scrapings

Serology: poultry respiratory panel

Aerobic culture: sinuses, trachea, lungs 

Oropharyngeal swab PCR: AI, END, Mycoplasma sp., ILT, IBV

Virus isolation: trachea, lung tissue

Direct electron microscopy: ILT, poxvirus

D1611748

Jethro 2 yr old rooster

Wheezy cough 6 months

Gaping, gurgles

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Intrathoracic “masses”

Granuloma? Fungal? Bacterial?

Neoplasia?

Histopathology!

PAS

aspergillosis

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Digestive system diseases

Crop dysfunction

‘Vomiting’

Diarrhea – vent feathers soiled with feces

bloody / non‐bloody

Viral

Pox 

ENDPoult enteritis (rotav.)

Bacterial

C. perfringens (NE) Salmonella sp.

Fungal

Candidiasis

Parasitic

Trichomoniasis

CapillariasisCoccidiosisHistomoniasis

AscaridiasisCestodiasis

Nutritional

Vitamin A deficiency

Digestive system diseases

Uni. Of Kentucky

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Crop impaction/stasis

Ingluvitis; candida, capillaria etc.

Obstructive; coelomic “mass”

Diet: long grasses, dry etc.

Neurogenic; vagal, ganglia (Marek’s)

Ingluvitis

Candidiasis 

Capillariasis – flock problem!

pheasant

Obstructive

Carcinomatosis, ascites, salpingitis

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Diet

“Rescue hen” with weight loss

“Choke” – death by tortilla

ENDV; Virulent/non‐v

Viral

ENDV, HPAI

Pox; ‘wet pox’ (mucosal form)

Clostridium spp.Necrotic enteritis (NE)

Salmonella spp.

Bacterial

Salmonella arizonae

CulturePCR

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Coccidiosis

Parasitic

Histomoniasis

Turkeys and chickens

Parasitic

Ascarids – not typically pathogenic(need A LOT)

Tapeworms – only few speciespathogenic

Parasitic

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Diagnosis of digestive tract diseases

Fecal swab or feces:

Salmonella PCR, culture 

Aerobic / anaerobic (Clostridium spp.) culture

Wet mount (coccidiosis)

Flotation

Histopathology

Reproductive system diseases

• Infection of the oviduct, coelom/peritoneum

• Internal layers

• ‘Carcinomatosis’

“Liver hemorrhagic syndrome”

Metabolic diseases

The “Big belly” chicken series

‘Big belly’ chicken I

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Salpingitis/Peritonitis/Salpingoperitonitis (SPS)

E. Coli

Acute SPS

Chronic SPS

E. ColiGallibacterium anatis 

SPS,

Internal layer

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‘Big belly’ chicken II

Carcinomatosis(disseminated carcinoma)

Ovarian/Oviductal/?Carcinoma

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PearlCrop stasis, occasional emptying

Carcinomatosisunknown origin

‘(Fatty) Liver Hemorrhagic Syndrome’

‘Big belly’ chicken III

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Overweight (obese) chickens

Pale livers (“fatty”)

Hemorrhages, hematomas

Capsular rupture 

Exsanguination

Sudden death

Trott et al., Vet Pathol., 2013

LHS associated with

LHS Conclusions

Obesity is a risk factor in female layers

Spring and summer warrant extra caution!

Misleading name of disease!: “Liver Hemorrhagic Syndrome”

Big belly ‘Bonus’ chicken

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MycoplasmaCholeraSalmonellaCoryza

Sudden death; systemic acute infections Pinpoint random fociFibrinous coelomitis

Gout(non-infectious)

Visceral urate deposits Articular urate deposits

Toxicoses Many possibilities – suspect?

Lead toxicosis: important public health issueegg, blood testingNO signs or postmortemFind source!!

Duck lead toxicosis

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Skin diseases

Parasitic

Mites 

Lice

Anemia, restlessness

Mites

Red mite, Northern fowl mite Always check vent feathers for

discoloration, matting

Rapid life cycle – treat frequent

Flock, coop problem

Can be underlying or have

underlying disease

Dr. A. Loretti

Scaly leg mites (Knemidecoptidae)

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Lice 

Eggs – diagnosis, repeat treatment 

D1611278

TurkeyChickenQuail

Pox viruscutaneous

Nervous system diseases

ViralMarek’s disease

END

HPAI

BacterialSalmonella enterica subsp. arizonaeMycoplasmosisListeria monocytogenes

Nutritional/ToxicVitamin E deficiencyPolyneuropathy: Vit B2 def (riboflavin)

Vit B1 def (thiamin)Lead poisoning Parasitic

Baylisascaris migration

Fungal AspergillosisDactylaria gallopova

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Vitamin E deficiency – Brain necrosis

Diagnosis of neurologic diseases

Histopathology  

PCR, serology 

Liver nutrition analysis, response to treatment 

Aerobic bacterial culture

Toxicology (brain/liver/kidney/crop contents/etc.)

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Sudden death

Know your breeds….

“Lymphoproliferative Diseases”

Marek’s Disease

Avian Leukosis/Sarcoma complex

Reticuloendotheliosis 

[virus  ‐ induced lymphomas]

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Lymphoproliferative Diseases

‐ Diagnostic challenge: 

Overlap between LPD lesions

IHC (research) only for some of the proteins, low sensitivity

PCR in specialty labs, can’t differentiate pathotypes

‐ Typically “presumptive diagnosis”

Marek’s Disease Virus 

Ubiquitous alpha herpesvirus

Oncogenic strain serotype 1 (MDV‐1)

MDV‐2 and ‐3 vaccine strains

Neurotropic

Marek’s DiseaseMost frequent diagnosis

Marek’s Disease

Classic presentation unilateral, droopy wing, splayed 

legs, ocular disease but depends which nerve it affects!

Lymphomas, nerves affected

Non‐lymphomatous MD ‐ immunosuppression

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Lymphomas –

diffuse/focal

Liver

Heart

ThymusSkin

Sciatic nerve

Brachial plexus Iliosacral plexus

MDVAffected nerves

D1108767

Lymphoid leukosis

Fibroma

Bursal lymphoma

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MDV or ALV

Thank you for your attention!