Difference between revisions of "Gill Hyperplasia"

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(Created page with "==Introduction== The gill has several important functions in fish physiology: '''respiration, nitrogenous excretion and fluid balance''' regulation. The anatomic structure of th...")
 
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Also known as: '''''Environmental Gill Disease — Bacterial Gill Disease
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==Introduction==
 
==Introduction==
The gill has several important functions in fish physiology: '''respiration, nitrogenous excretion and fluid balance''' regulation.
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The most common response of the [[Gills|gill]] to damage is '''hyperplasia and hypertrophy of epithelial cells''', which results in '''shortening, rounding and fusion''' of the secondary lamellae. Sometimes even the primary lamellae are affected.
 
 
The anatomic structure of the gills helps in its functions by providing a '''large and very thin surface'''. The gill filaments are divided into multiple finger-like projections, the primary lamellae, which in turn are divided into secondary lamellae.
 
 
 
There is usually very little mucus on the gill surface.
 
 
 
The most common reponse of the gill to damage is '''hyperplasia and hypertrophy of epithelial cells''', which results in '''shortening, rounding and fusion''' of the secondary lamellae. Sometimes even the primary lamellae are affected.
 
  
 
This severely affects the structure and function of the gills and reduces the surface area available for exchange. This also predisposes the gills to further bacterial colonisation and potential septicaemia.
 
This severely affects the structure and function of the gills and reduces the surface area available for exchange. This also predisposes the gills to further bacterial colonisation and potential septicaemia.
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:'''Parasites''': ''[[Ichthyophthirius multifiliis|Ichthyophthirius]]'', ''Amlyoodinium''
 
:'''Parasites''': ''[[Ichthyophthirius multifiliis|Ichthyophthirius]]'', ''Amlyoodinium''
 
:'''Bacteria'''
 
:'''Bacteria'''
:'''Environmental toxins''': ammonia, nitrite, heavy metals  
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:'''Environmental toxins''': ammonia, [[Nitrite Toxicity|nitrite]], heavy metals  
 
:'''Poor water quality'''
 
:'''Poor water quality'''
 
:'''Pantothenic acid deficiency'''
 
:'''Pantothenic acid deficiency'''
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==Diagnosis==
 
==Diagnosis==
'''Gill biopsies''' should be performed on dead fish to examing their gross and histological appearance.
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'''Gill biopsies''' should be performed on dead fish to examine their gross and histological appearance.
  
 
'''Histology''' will reveal shortening, fusion and clubbing of the secondary lamellae.
 
'''Histology''' will reveal shortening, fusion and clubbing of the secondary lamellae.
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Roberts, R. (2001) '''Fish Pathology''' ''Elsevier Health Sciences''
 
Roberts, R. (2001) '''Fish Pathology''' ''Elsevier Health Sciences''
  
[[Category:To Do - Helen]]
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[[Category:To Do - Review]]
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{{review}}
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[[Category:Fish Diseases]]
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[[Category:Expert Review - Exotics]]

Revision as of 15:33, 30 October 2011

Also known as: Environmental Gill Disease — Bacterial Gill Disease

Introduction

The most common response of the gill to damage is hyperplasia and hypertrophy of epithelial cells, which results in shortening, rounding and fusion of the secondary lamellae. Sometimes even the primary lamellae are affected.

This severely affects the structure and function of the gills and reduces the surface area available for exchange. This also predisposes the gills to further bacterial colonisation and potential septicaemia.

Excessive mucus production also compromises gill function.

Causes

Any irritation can lead to gill hyperplasia, most commonly from bacteria or parasites or from poor water quality.

The most common causes are as follows:

Protozoa: Trichodina, Chilodonella, Ichtyobodo
Parasites: Ichthyophthirius, Amlyoodinium
Bacteria
Environmental toxins: ammonia, nitrite, heavy metals
Poor water quality
Pantothenic acid deficiency

Clinical Signs

These are primarily of respiratory compromise: rapid opercular movements, lethargy, grouping near inlets, tachypnoea.

Fish may show lesions characteristic for a particular disease.

There will be increased mortality.

Diagnosis

Gill biopsies should be performed on dead fish to examine their gross and histological appearance.

Histology will reveal shortening, fusion and clubbing of the secondary lamellae.

If gill hyperplasia is detected on a wet mount this indicates that severe pathology is present.

Treatment

The underlying cause should be dealt with.

This may include chemical treatment of the water to eliminate parasites, protozoa or bacteria.

Improvement of the water quality is also important and oxygen and toxin levels should be monitored.


Gill Hyperplasia Learning Resources
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Flashcards
Test your knowledge using flashcard type questions
Ornamental Fish Q&A 20


References

Noga, E. (2010) Fish disease: diagnosis and treatment' John Wiley and Sons

Rosenthal, K. (2008) Rapid review of exotic animal medicine and husbandry: pet mammals, birds, reptiles, amphibians, and fish Manson Publishing

Roberts, R. (2001) Fish Pathology Elsevier Health Sciences