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Diagnosis is confirmed by demonstrating ''[[Giardia]]'' antigen, trophozoites or cysts in the faeces. The simplest method is to stain a fresch faecal smear with Diff-Quik or Lugol's iodine to reveal trophozoites. ''[[Giardia]]'' trophozoites are approximately 8 x 15 microns in dimension, tear-drop shaped organisms and contain two nuclei. They can be seen to move in a "falling leaf" pattern in wet mounts.  
 
Diagnosis is confirmed by demonstrating ''[[Giardia]]'' antigen, trophozoites or cysts in the faeces. The simplest method is to stain a fresch faecal smear with Diff-Quik or Lugol's iodine to reveal trophozoites. ''[[Giardia]]'' trophozoites are approximately 8 x 15 microns in dimension, tear-drop shaped organisms and contain two nuclei. They can be seen to move in a "falling leaf" pattern in wet mounts.  
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As cysts are relatively "heavy", cysts must be floatated in higher density solutions prior to visualisation. Suitable solutions include zinc sulphate solution and sugar flotation solution. Centrifugal flotation in zinc sulphate solution is preferred as cysts can be envisaged with minimal distortion. Cysts are around 12 microns long
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As cysts are relatively "heavy", cysts must be floatated in higher density solutions prior to visualisation. Suitable solutions include zinc sulphate solution and sugar flotation solution. Centrifugal flotation in zinc sulphate solution is preferred as cysts can be envisaged with minimal distortion. Cysts are around 12 microns long and, if not distorted, oval in shape. When looking for cysts, three samples collected at two to three day intervals should be examined as shedding is intermittent.
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*Faecal examination
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Commercial ELISA tests are now available for the detection of ''[[Giardia]]'' antigen in faeces. These include the Snap ''[[Giardia]]'' test from IDEXX and the ProSpectT/Giardia ELISA from Alexon-Trend.
**Cysts need to be distinguished from pollen grains and yeasts
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*Cyst excretion is intermittent
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===Endoscopy===
**Faeces need to be collected over a 3 day period
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*Cysts are '''heavy'''
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The above tests may also be performed using duodenal aspirates obtained by endoscopy.
**Needs higher density flotation fluids
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**Do not float well in saturated sodium chloride solution
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*Immunoassays
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**Detect cyst antigen in faeces
      
==Treatment==
 
==Treatment==
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