A Basic Approach to Poultry Disease Diagnosis

Mohamed El-GazzarDVM, MAM, PhD, DACPV

Assistant Professor Poultry Extension Veterinarian

The Ohio State University

Trends in Food Production

• Organic

• Free Range

• Produce local/Eat local

• Shift in Poultry Population

Urban Chicken Ownership in Four U.S. Cities

• Denver• Los Angles• Miami• New York

– Around 1% of all households– Quadruple (4%) within 5 years– Not enough veterinary services

Backyard flocks Not only Urban

• Urban, Suburban and Rural• Few birds to several hundreds (Average 49

birds)• Still food animals not Pets• Population medicine • Mainly Chicken• Some Turkey• Other species

But they are falling through the crakes!!

• Wall Street Journal http://online.wsj.com/news/articles/SB10001424127887323527004579081812563033586

• A gap that needs to be filled

• Small and mixed Animal Practices or Even Poultry Specialists

Poultry Disease Diagnosis and Control

• Clinical History• Clinical signs• Necropsy• Laboratory diagnosis• Control

Rule Out List

• Clinical signs grouping– Respiratory– Digestive – Musculoskeletal– Neurological – Others

• Samples to collect• General control

Poultry Disease Diagnosis

Necropsy

• Extremely useful in poultry • Recently dead • Clear clinical picture• Sample collection

http://partnersah.vet.cornell.edu/veterinarians/avian-necropsy-examination

Usual Clinical Samples

• Blood serology• Swabs bacterial isolation• Organs virus isolation• Organs histopathology

Disclaimer

• Non of lists is comprehensive

• Only most common

• Starting point

Respiratory Diseases

General signs:• Mortality• Anorexia/Fever/lethargy• Coughing/Sneezing• Rales/Weezing• Nasal/Occular discharges• Swollen head/swollen sinuses• inflamed eyelids

Respiratory Diseases

Gross lesions:• Inflammation of:

– head tissues– nasal cavity– conjunctivitis

• Tracheitis• Pneumonia • Air sacculitis• Polyserositis

Turbinate

Normal Trachea

Inflamed Trachea

Early Airsacculitis

PolyserositisPnuemonia

Respiratory DiseasesRule out list:• Newcastle disease• Infectious bronchitis• Infectious laryngotracheitis• Avian Influenza• Mycoplasmosis (4 species)• Colibacillosis (E. coli)• Fowl Cholera (Pasteurella multocida)• Infectious coryza (Avibacterium paragallinarum)• Turkey coryza (Bordetella avium)• Aspergillosis• Cryptosporidiosis• Gape worms (Syngamus trachea)

Respiratory Sampling

Samples:• Blood Serology• Eye lids, Trachea, lungs and

kidney Histopath• Eye lids, Trachea, lungs and

kidney Virus isolation• Trachea/choana/airsacs

swabing Bacterial isolation

Digestive Diseases

General signs:• Mortality• Anorexia/Fever/lethargy• Dehydration • Diarrhea/Loose droppings

(watery/bloody)• Pasty vent/wet litter

Normal Droppings

Loose Droppings

Digestive Diseases

Gross lesions:• Intestinal mucosa• Intestinal content• Parasite• Pathognomonic

lesions

Digestive DiseasesRule out List:• Hemorrhagic Enteritis Virus• Turkey Corona Virus • Clostridium species• Salmonella species• Coccidia species• Histomonas meliagridis (Black head)• Trichomonus gallinae• Intestinal helminthes (Tapeworms and

Round worms)

Digestive Diseases Sampling

Samples:• Intestine/liver/other

histopathology• Intestinal/liver/spleen swabs bacterial isolation

• Intestinal scrapings• Impression smears

Coccidosis• Most common protozoan

parasite• Mortality/economic losses• Bloody Diarrhea E. tenella• Diarrhea (not always bloody)• Predispose for Clostridium

enteritis• Vaccines• Amprolium for prevention and

control

Eimeria acervulina

Eimeria maxima

Not All Internal Parasites are Intestinal

• Histomonus meliagridis(Black head)– Liver lesions – Cecal cores

• Syngamus trachea (Tracheal worms or Gapeworms)

Histomonus meliagridis

Syngamus trachea

External Parasites• Lice• Mites

– Red mites– Northern fowl mites– Scaly leg mite

• Powdering, dusting or spraying of insecticides– Birds and Environment– Minimum of Two treatments– 7 days interval

Red Mites Northern fowl Mites

Chicken Lice

Musculoskeletal Diseases

General Signs:• Mortality• Paralysis• Lameness• Down birds

Musculoskeletal Diseases

Gross Lesions:• Nerve inflammation • Joint inflammation• Foot pad infection

(bumblefoot)• Weak/soft bones

(rickets or osteoporosis)

• Bone deformities

Musculoskeletal Diseases

Rule out list:• Marek’s disease (nerve involvement)• Reo virus • Staphylococcus aureus• E. coli• Pasteurella maltocida• Mycoplasma synoviea• Calcium/Phosphorus deficiency• Ionophore toxicity• Genetic deformities

Musculoskeletal Diseases

Samples:• Swab lesions bacterial isolation• Nerve/muscle/affected tissue histopathology• Feed samples feed analysis

Neurological Diseases

General signs:• Paralysis • Ataxia • Torticollis• Tremors

Neurological Diseases

Rule out List:• Marek’s Disease• Avian Encephalomylitis• Newcastle Disease• Influenza• Pasteurella• E. coli • Nutritional deficiency• Ionophore toxicity

Neurological Diseases SamplingSamples:• Nerves/brain histopathology

• Lesions other organs histopathology

• Organs virus isolation

• Blood serology

• Feed feed analysis

Vitamin E difficiency

General signs:• 3 forms of the disease

– Encepahlomalacia– Exudative diathesis – Muscular dystrophy

Exudative diathesis

Muscular dystrophy

Other Common Conditions in Backyard Flocks

Egg Production problemsBirds are not laying??• Review lighting• Review feeding• Water consumption• Infectious causes

– Egg peritonitis– New castle– Infectious bronchitis– Laryngotracheitis– Influenza – Egg drop syndrome– Pasteurella– Coriza– Mycotoxins in feed

Egg peritonitis

Pox virus

• Dry form and wet form• Collect samples for histopathology

Dry form Wet form Inclusion bodies

Tumor Viruses (3 viruses)

1- Marek’s Disease2- Leukosis/Sarcoma3- Reticuloendotheliosis

Recommended References

• Avian Disease Manual: 7th edition 2013

• A laboratory Manual for the Isolation, Identification and Characterization of Avian Pathogens: 5th edition 2008

• Diseases of Poultry: 13th edition 2013

Take Home• Good management and Biosecurity

Clinical signs and Lesions

List of Diseases

Sampling and treatment

Questions?