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Created page with "==Introduction== Hepatitis refers to '''inflammation of the liver''' which can lead to gross lesions visible at necropsy. In birds, these lesions are seldom diagnostic, as nume..."
==Introduction==
Hepatitis refers to '''inflammation of the liver''' which can lead to gross lesions visible at necropsy.
In birds, these lesions are seldom diagnostic, as numerous infectious diseases cause hepatitis. Liver inflammation usually occurs alongside '''systemic infection''' and changes in other organs such as the '''spleen and lungs''' may be helpful in obtaining a diagnosis.
'''Histopathology''' can usually be more revealing, especially if special stains are used. '''Electron microscopy, viral isolation, DNA probes and special cultures''' can be used to get an exact aetiological diagnosis.
Most causes of hepatitis are difficult to diagnose in the '''live bird''', unless the enlarged liver causes abdominal distension or biochemical tests produce significant results.
Common causes of hepatitis are as follows:
==Viral Infections==
===Psittaciformes===
'''Pacheco's disease''' caused by a herpesvirus
'''[[Polyomavirus|Avian polyomavirus]]'''
'''Acute [[Psittacine Beak and Feather Disease]]'''
'''Adenovirus inclusion body hepatitis'''
'''Reovirus-associated hepatitis'''
===Falconiformes===
'''Inclusion Body Hepatitis'''
===Columbiformes, Strigiformes and others===
'''Herpesvirus'''
===Anseriformes===
'''Goose Virus Hepatitis'''
===Galliformes===
'''[[Mareks Disease]]'''
==Bacterial Infections==
Gram-positive and gram-negative bacteria can cause liver disease, usually secondary to septicaemia or enteritis.
===Gram-positive===
''Staphylococcus'' and ''Streptococcus'' species are the most common organisms isolated. They '''disseminate through the blood''' from chronic necrotising skin lesions or can reach the liver by extension from adjacent air sacs.
''Clostridia'' are of intestinal origin and can cause hepatitis.
''Listeria monocytogenes'' can also cause disease, although it is a rare pathogen of birds.
===Gram-negative===
These are the most common causes of systemic bacterial infection.
'''Members of the Enterobacteriaceae''', including ''E. coli'', ''Klebsiella'', ''Proteus'', ''Salmonella'', ''Yersinia'' and ''Enterobacter'' are common isolates.
This is usually secondary to invasion from the gut or extension up the biliary tree.
===Mycobacteria===
'''''[[Mycobacterium avium|M. avium]]''''' infects all birds.
===Intracellular bacteria===
''[[Chlamydophila psittaci]]'' causes psittacosis and hepatomegaly with yellow foci of necrosis.
==Fungal Infections==
This is usually from '''extension from the lungs or air sacs''', or as a result of haematologic spread.
''[[Aspergillosis|Aspergillus]]'' species most commonly affect the liver.
Systemic ''[[Candidiasis - Birds|Candida]]'' infection, particularly in immunosuppressed birds, can also result in liver invasion.
==Parasites==
===Apicomplexa===
''[[Toxoplasma gondii]]''
''[[Sarcocystis]]''
===Hemoprotozoa===
''Plasmodium''
''Leukocytozoon''
''Hemoproteus''
===Sarcomastigophora===
''[[Trichomonosis - Birds|Trichomonas gallinae]]'' infections which become generalised.
''[[Histomonas|Histomonas meleagridis]]'' which is predominantly a disease of turkeys.
===Microspora===
''Encephalitozoon hellem''
==Toxic Hepatitis==
'''Ingestion of heavy metals''' such as [[Lead Poisoning|lead]] or zinc.
Vitamin D toxicity
'''[[Mycotoxins]]''' such as Aflatoxins
==Idiopathic==
'''Chronic-active hepatitis''', or cirrhosis, is common in psittacine birds, particularly parrots, cockatiels, mackaws and budgerigars. The cause of the hepatitis cannot be determined due to the chronicity of the lesions.
{{Learning
|flashcards = [[Avian Medicine Q&A 11]]
}}
==References==
Samour, J. (2000) '''Avian Medicine''' ''Elsevier Health Sciences''
Schmidt, R. (2003) '''Pathology of pet and aviary birds''' ''Wiley-Blackwell''
Doneley, R. (2010) '''Avian medicine and surgery in practice''' ''Manson Publishing''
[[Category:To Do - Helen]]
[[Category:To Do - Review]]
Hepatitis refers to '''inflammation of the liver''' which can lead to gross lesions visible at necropsy.
In birds, these lesions are seldom diagnostic, as numerous infectious diseases cause hepatitis. Liver inflammation usually occurs alongside '''systemic infection''' and changes in other organs such as the '''spleen and lungs''' may be helpful in obtaining a diagnosis.
'''Histopathology''' can usually be more revealing, especially if special stains are used. '''Electron microscopy, viral isolation, DNA probes and special cultures''' can be used to get an exact aetiological diagnosis.
Most causes of hepatitis are difficult to diagnose in the '''live bird''', unless the enlarged liver causes abdominal distension or biochemical tests produce significant results.
Common causes of hepatitis are as follows:
==Viral Infections==
===Psittaciformes===
'''Pacheco's disease''' caused by a herpesvirus
'''[[Polyomavirus|Avian polyomavirus]]'''
'''Acute [[Psittacine Beak and Feather Disease]]'''
'''Adenovirus inclusion body hepatitis'''
'''Reovirus-associated hepatitis'''
===Falconiformes===
'''Inclusion Body Hepatitis'''
===Columbiformes, Strigiformes and others===
'''Herpesvirus'''
===Anseriformes===
'''Goose Virus Hepatitis'''
===Galliformes===
'''[[Mareks Disease]]'''
==Bacterial Infections==
Gram-positive and gram-negative bacteria can cause liver disease, usually secondary to septicaemia or enteritis.
===Gram-positive===
''Staphylococcus'' and ''Streptococcus'' species are the most common organisms isolated. They '''disseminate through the blood''' from chronic necrotising skin lesions or can reach the liver by extension from adjacent air sacs.
''Clostridia'' are of intestinal origin and can cause hepatitis.
''Listeria monocytogenes'' can also cause disease, although it is a rare pathogen of birds.
===Gram-negative===
These are the most common causes of systemic bacterial infection.
'''Members of the Enterobacteriaceae''', including ''E. coli'', ''Klebsiella'', ''Proteus'', ''Salmonella'', ''Yersinia'' and ''Enterobacter'' are common isolates.
This is usually secondary to invasion from the gut or extension up the biliary tree.
===Mycobacteria===
'''''[[Mycobacterium avium|M. avium]]''''' infects all birds.
===Intracellular bacteria===
''[[Chlamydophila psittaci]]'' causes psittacosis and hepatomegaly with yellow foci of necrosis.
==Fungal Infections==
This is usually from '''extension from the lungs or air sacs''', or as a result of haematologic spread.
''[[Aspergillosis|Aspergillus]]'' species most commonly affect the liver.
Systemic ''[[Candidiasis - Birds|Candida]]'' infection, particularly in immunosuppressed birds, can also result in liver invasion.
==Parasites==
===Apicomplexa===
''[[Toxoplasma gondii]]''
''[[Sarcocystis]]''
===Hemoprotozoa===
''Plasmodium''
''Leukocytozoon''
''Hemoproteus''
===Sarcomastigophora===
''[[Trichomonosis - Birds|Trichomonas gallinae]]'' infections which become generalised.
''[[Histomonas|Histomonas meleagridis]]'' which is predominantly a disease of turkeys.
===Microspora===
''Encephalitozoon hellem''
==Toxic Hepatitis==
'''Ingestion of heavy metals''' such as [[Lead Poisoning|lead]] or zinc.
Vitamin D toxicity
'''[[Mycotoxins]]''' such as Aflatoxins
==Idiopathic==
'''Chronic-active hepatitis''', or cirrhosis, is common in psittacine birds, particularly parrots, cockatiels, mackaws and budgerigars. The cause of the hepatitis cannot be determined due to the chronicity of the lesions.
{{Learning
|flashcards = [[Avian Medicine Q&A 11]]
}}
==References==
Samour, J. (2000) '''Avian Medicine''' ''Elsevier Health Sciences''
Schmidt, R. (2003) '''Pathology of pet and aviary birds''' ''Wiley-Blackwell''
Doneley, R. (2010) '''Avian medicine and surgery in practice''' ''Manson Publishing''
[[Category:To Do - Helen]]
[[Category:To Do - Review]]