Difference between revisions of "Candidiasis"

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=Introduction=
==Introduction==
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Candidiasis is a fungal infection caused by [[Candida spp.|''Candida'' spp.]], [[File:C albicans germ tubes.jpg|200px|right|thumb|''Candida'' spp]] most commonly ''Candida ablicans'' that affects many species.
[[File:C albicans germ tubes.jpg|200px|right|thumb|''Candida'' spp]]
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The yeast is normally present on skin and in [[Alimentary System Overview - Anatomy & Physiology|GI tract]] and symptoms of disease are usually only seen in immunocompromised animals following opportunistic infection.  It is most common in the bird but has also been reported in horses, pigs, cows, sheep, cats and dogs - in particular neonates.  
Candidiasis is a '''fungal infection''' caused by [[Candida spp.|''Candida'' spp.]],  most commonly '''''Candida ablicans''''' that affects many species.
 
  
The yeast is normally present on '''skin''' and in the [[Alimentary System Overview - Anatomy & Physiology|GI tract]]. Symptoms of disease are usually only seen in '''immunocompromised''' animals following '''opportunistic''' infection.  It is most common in the bird (see [[Candidiasis - Birds]]) but has also been reported in [[Candidiasis – Rabbit|rabbits]], horses, pigs, cows, sheep, cats and dogs - in particular neonates.
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==Clinical signs==  
 
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Lesions are found on mucous membranes and at mucocutaneous junctions most commonly. The disease will usually remain localised to the mucocutaneous junctions, but on rare occasions it may spread systemically.
==Clinical Signs==  
 
Lesions are found on '''mucous membranes''' and at '''mucocutaneous junctions''' most commonly. The disease will usually remain '''localised''' to the mucocutaneous junctions, but on rare occasions it may spread '''systemically'''.
 
  
 
Gross clinical signs include:
 
Gross clinical signs include:
* '''Exudative''', '''papular''', '''pustular''' to '''ulcerative dermatitis'''
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* Exudative, papular, pustular to ulcerative dermatitis
* '''Raised''', '''circular white plaques''' or '''ulcers''' with overlying '''scabs'''
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* Raised, circular, white plaques or ulcers with overlying scabs
* '''Keratinous thickening''' of tissue
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* Keratinous thickening of tissue
* [[Stomatitis|'''Stomatitis''']] and [[Otitis Externa - Cat and Dog|'''otitis externa''']]
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* Stomatitis and otitis externa
  
 
Microscopically there is evidence of:
 
Microscopically there is evidence of:
*Spongiotic neutrophilic pustular [[Inflammation|'''inflammation''']]
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*Spongiotic neutrophilic pustular inflammation
*'''Parakeratosis'''
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*Parakeratosis
*'''Ulcerations'''
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*Ulcerations
*Superficial [[Exudate|'''exudate''']] containing organisms
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*Superficial exudate containing organisms
  
Infection may also cause a variety of '''other clinical signs''' depending on the '''species''' and the '''site of infection''', for example [[Mastitis|mastitis]], [[Arthritis|arthritis]], [[Diarrhoea|diarrhoea]] and general malaise.
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Infection may cause a also cause a variety of other clinical signs depending on the species and the site of infection, for example mastitis, arthritis, diarrhoea and general malaise.
  
 
==Predisposing factors==
 
==Predisposing factors==
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* Indwelling urinary or intravenous catheters
 
* Indwelling urinary or intravenous catheters
 
* Antibiotic administration
 
* Antibiotic administration
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* Corticosteroid administration
  
 
==Diagnosis==
 
==Diagnosis==
Diagnosis can be confirmed via '''microscopic examination''' and '''identification of the fungus''' following a '''skin scrape''' of the lesion. The fungus should be visible after staining with a Gram, Methylene Blue or Wrights stain. It is a '''gram-positive ovoid''', '''budding yeast''' with or without '''hyphae'''. '''Culture''' of a sample in Sabourauds Dextrose agar or Blood agar should also confirm diagnosis.
+
Diagnosis can be confirmed via microscopic examination and identification of the fungus following a skin scrap of the lesion. The fungus should be visible after staining with a Gram, Methylene Blue or Wrights stain. It is a gram positive ovoid, budding yeast with or without hyphae. Culture of a sample in Sabourauds Dextrose agar or Blood agar should also confirm diagnosis.
  
 
==Treatment==
 
==Treatment==
'''Topical''' or '''systemic anti-fungals''' are used to treat the infection.  
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Topical anti-fungals are used to treat the infection.
 +
 
 +
 
 +
=Candidasis in birds=
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==Signalment==
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Candidiasis ''aka'' thrush/sour crop/crop mycosis is common in '''neonatal psittacine birds'''. It occurs primarily as a result of '''immunosuppression''' and '''trauma''' to the ingluvies. Hypothermia, feeding too cold or too hot formula which results in crop-burn, poor nutrition, longterm antibiotic therapy, hypovitaminosis A and systemic illness from other causes are all predisposing causes.
 +
 
 +
==Clinical Sings==
 +
The bird may present with '''inflammation''' and '''delayed emptying''' of the '''ingluvies'''.
 +
 
 +
==Diagnosis==
 +
Diagnosis is based on '''identification of oval yeasts''' and '''hyphae''' on '''cytological smears''' taken from swabs and crop washes or aspirates. '''Wrights stain''' can be used to demonstrate the yeasts. There should be no evidence of an inflammatory response. The presence of '''hyphae''' indicates that the crop may have been penetrated and the infection has '''spread systemically'''.
  
 +
==Treatment==
 +
An '''antifungal drug''' is indicated for the treatment of candidiasis. The presence of hyphae is suggestive of invasion of the mucosa by the yeast and the potential for a systemic infection. Therefore, a '''systemic antifungal''' such as oral itraconazole (for 7 days) is recommended  along with a topical antifungal such as nystatin BID or TID for 7–10 days.
 +
.
 
==Prognosis==
 
==Prognosis==
Prognosis depends on both the severity of infection and the animal affected.
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The presence of hyphae on cytological examination suggests a severe infection and potential systemic spread, and therefore a '''poor''' prognosis. Without evidence of hyphae the prognosis is improved.
 
 
<big><b>
 
Also see:
 
:[[Candidiasis - Birds|Candidiasis in Birds]]
 
:[[Candidiasis – Rabbit|Candidiasis in Rabbits]]
 
</b></big>
 
  
 
==References==
 
==References==
 +
Forbes NA & Altman RB (1998) '''Self-Assessment Colour Review Avian Medicine''' ''Manson Publishing Ltd''
  
Merck & Co (2009) '''The Merck Veterinary Manual''' (Ninth Edition), ''Merial''
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Girling, S (2004) '''Diseases of the digestive tract of psittacine birds''' ''In Practice 2004 26: 146-15''
 
 
  
{{review}}
 
  
{{OpenPages}}
 
  
 
[[Category:Cutaneous Mycoses]]
 
[[Category:Cutaneous Mycoses]]
[[Category:Expert Review]]
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[[Category:To Do - Fungi]]
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[[Category: To Do - Siobhan Brade]]

Revision as of 16:01, 2 August 2011

Introduction

Candidiasis is a fungal infection caused by Candida spp.,

Candida spp

most commonly Candida ablicans that affects many species.

The yeast is normally present on skin and in GI tract and symptoms of disease are usually only seen in immunocompromised animals following opportunistic infection. It is most common in the bird but has also been reported in horses, pigs, cows, sheep, cats and dogs - in particular neonates.

Clinical signs

Lesions are found on mucous membranes and at mucocutaneous junctions most commonly. The disease will usually remain localised to the mucocutaneous junctions, but on rare occasions it may spread systemically.

Gross clinical signs include:

  • Exudative, papular, pustular to ulcerative dermatitis
  • Raised, circular, white plaques or ulcers with overlying scabs
  • Keratinous thickening of tissue
  • Stomatitis and otitis externa

Microscopically there is evidence of:

  • Spongiotic neutrophilic pustular inflammation
  • Parakeratosis
  • Ulcerations
  • Superficial exudate containing organisms

Infection may cause a also cause a variety of other clinical signs depending on the species and the site of infection, for example mastitis, arthritis, diarrhoea and general malaise.

Predisposing factors

  • Immunosuppressive drugs
  • Immunosuppressive disease
  • Indwelling urinary or intravenous catheters
  • Antibiotic administration
  • Corticosteroid administration

Diagnosis

Diagnosis can be confirmed via microscopic examination and identification of the fungus following a skin scrap of the lesion. The fungus should be visible after staining with a Gram, Methylene Blue or Wrights stain. It is a gram positive ovoid, budding yeast with or without hyphae. Culture of a sample in Sabourauds Dextrose agar or Blood agar should also confirm diagnosis.

Treatment

Topical anti-fungals are used to treat the infection.


Candidasis in birds

Signalment

Candidiasis aka thrush/sour crop/crop mycosis is common in neonatal psittacine birds. It occurs primarily as a result of immunosuppression and trauma to the ingluvies. Hypothermia, feeding too cold or too hot formula which results in crop-burn, poor nutrition, longterm antibiotic therapy, hypovitaminosis A and systemic illness from other causes are all predisposing causes.

Clinical Sings

The bird may present with inflammation and delayed emptying of the ingluvies.

Diagnosis

Diagnosis is based on identification of oval yeasts and hyphae on cytological smears taken from swabs and crop washes or aspirates. Wrights stain can be used to demonstrate the yeasts. There should be no evidence of an inflammatory response. The presence of hyphae indicates that the crop may have been penetrated and the infection has spread systemically.

Treatment

An antifungal drug is indicated for the treatment of candidiasis. The presence of hyphae is suggestive of invasion of the mucosa by the yeast and the potential for a systemic infection. Therefore, a systemic antifungal such as oral itraconazole (for 7 days) is recommended along with a topical antifungal such as nystatin BID or TID for 7–10 days. .

Prognosis

The presence of hyphae on cytological examination suggests a severe infection and potential systemic spread, and therefore a poor prognosis. Without evidence of hyphae the prognosis is improved.

References

Forbes NA & Altman RB (1998) Self-Assessment Colour Review Avian Medicine Manson Publishing Ltd

Girling, S (2004) Diseases of the digestive tract of psittacine birds In Practice 2004 26: 146-15