Changes

In aquariums, causes include '''leaks in pumps or valve systems''' that can suck air under pressure or '''sudden temperature gradients'''. Fish '''transported by air''' may also develop gas bubble disease.

In aquariums, causes include '''leaks in pumps or valve systems''' that can suck air under pressure or '''sudden temperature gradients'''. Fish '''transported by air''' may also develop gas bubble disease.

'''Heavy algal blooms''' have also been blamed, by producing more oxygen than can diffuse into the water which supersaturates the pond.

'''Heavy [[Algal Bloom|algal blooms]]''' have also been blamed, by producing more oxygen than can diffuse into the water which supersaturates the pond.

Most gas embolic are produced by '''excess nitrogen''' because oxygen is assimilated metabolically and thus less likely to form persistent bubbles. However, very high oxygen levels are dangerous.

Most gas emboli are produced by '''excess nitrogen''' because oxygen is assimilated metabolically and thus less likely to form persistent bubbles. However, very high oxygen levels are dangerous.

When fish breathe supersaturated water, the excess gas can form '''emboli''' in various tissues. The severity of the disease depends on the number of gas bubbles formed and the tissues affected. '''Brain damage''', behavioural abnormalities and death may all occur.

When fish breathe supersaturated water, the excess gas can form '''emboli''' in various tissues. The severity of the disease depends on the number of gas bubbles formed and the tissues affected. '''Brain damage''', behavioural abnormalities and death may all occur.

==Clinical Signs==

==Clinical Signs==

'''Acute gas bubble disease''': acute '''mortality''' may occur in minutes. Eggs float to the surface and fish may show '''hyperinflation of their swim bladder''', cranial swelling, '''exophthalmos''', blindness, swollen gill lamellae, pneumoperitoneum or gass bubbles in the yolk sac. Up to 100% of fish may die.

'''Acute gas bubble disease''' manifests as acute '''mortality''' and may occur in minutes. Eggs float to the surface and fish may show '''hyperinflation of their swim bladder''', cranial swelling, '''exophthalmos''', blindness, swollen gill lamellae, pneumoperitoneum or gass bubbles in the yolk sac. Up to 100% of fish may die.

'''Chronic gas bubble disease''': there are a few mortalities, hyperinflation of the swim bladder, '''emboli''' in the gastrointestinal tract and mouth, and '''secondary infections''' which can lead to higher mortality rates.

'''Chronic gas bubble disease''' results in a few mortalities, hyperinflation of the swim bladder, '''emboli''' in the gastrointestinal tract and mouth, and '''secondary infections''' which can lead to higher mortality rates.

==Diagnosis==

==Diagnosis==

The clinical signs are suggestive but fish may die suddenly without apparent cause.

The clinical signs are suggestive but fish may die suddenly without apparent cause.

The '''presence of gas emboli''' is characteristic. Bubbles may be squeezed from a fin or gill clip whilst it is help underwater.

The '''presence of gas emboli''' is characteristic. Bubbles may be squeezed from a fin or gill clip whilst it is held underwater.

The total concentration of dissolved gas in the water source should be measured using a '''saturometer'''.

The total concentration of dissolved gas in the water source should be measured using a '''saturometer'''.

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

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

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[[Category:To Do - Review]]

[[Category:Fish Diseases]]

[[Category:Expert Review - Exotics]]