There are four main types of disease affecting poultry: metabolic and nutritional diseases; infectious diseases; parasitic diseases; and behavioural diseases.
Metabolic and nutritional diseases
These are conditions caused by a disturbance of normal metabolic functions either through a genetic defect, inadequate or inappropriate nutrition or impaired nutrient utilisation. These include Fatty Liver Syndrome, Perosis (or slipped tendon), Rickets and Cage Layer Fatigue.
An infectious disease is any disease caused by invasion of a host by a pathogen which subsequently grows and multiplies in the body. Infectious diseases are often contagious, which means they can be spread directly or indirectly from one living thing to another. These include Avian Encephalomyelitis, Avian Influenza, Avian Tuberculosis, Chicken Anaemia Virus Infection (or CAV), Chlamydiosis, Egg Drop Syndrome (or EDS), Fowl Cholera (or Pasteurellosis), Fowl Pox, Infectious Bronchitis, Infectious Bursal Disease (or Gumboro), Infectious Coryza, Infectious Laryngotracheitis, Lymphoid Leukosis, Marek’s Disease, Mycoplasmosis, Necrotic Enteritis, Newcastle Disease and Salmonellosis.
Parasitic diseases are infections or infestations with parasitic organisms. They are often contracted through contact with an intermediate vector, but may occur as the result of direct exposure. A parasite is an organism that lives in or on, and takes its nourishment from, another organism. A parasite cannot live independently. These include Coccidiosis, Cryptosporidiosis, Histomoniasis, Lice and Mites, Parasitic Worms (or Helminths), Toxoplasmosis and Trichomoniasis.
Abnormal behavioural patterns can lead to injury or ill health of the abnormally behaving bird and/or its companions. These include Cannibalism (or aggressive pecking).
Diseases caused by Viruses
Big Liver and Spleen Disease
Chicken Anaemia Virus Infection (or CAV)
Egg drop syndrome (or EDS)
Inclusion Body Hepatitis (or Fowl adenovirus type 8 )
Infectious Bursal Disease (or Gumboro)
Lympoid Tumour Disease (Reticuloendotheliosis)
Marek’s Disease Virus or MDV
Runting/stunting and malabsorption syndromes
Viral Arthritis (Tenosynovitis)
Diseases caused by Chlamydia
Diseases caused by Mycoplasmas
Mycoplasmosis – MG (Mycoplasma gallisepticum; MG infection; Chronic Respiratory Disease)
Mycoplasmosis – MS (Mycoplasma synoviae; infectious synovitis)
Diseases caused by Bacteria
Fowl Cholera (or pasteurellosis)
Spirochaetosis (Avian Intestinal Spirochaetosis)
Tuberculosis (Avian Tuberculosis)
Diseases caused by Fungi
Moniliasis (Candidiasis; crop mycosis)
Diseases caused by Protozoa
Diseases caused by Internal Parasites
Diseases caused by External Parasites
Several types of louse (insect; plural – lice)
Stickfast flea (insect)
Several types of mite (acarid)
Diseases caused by Metabolic Disorders
Cage Layer Fatigue and Rickets
Fatty Liver Haemorrhagic Syndrome
Diseases caused by environmental factors
Cannibalism (or aggressive pecking)