Difference between revisions of "Epizootic Lymphangitis"

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(Created page with '*''Histoplasma capsulatum'' var. ''farciminosum'' **Similar to ''H. capsulatum'' *Occurs in horses, donkeys and mules *90% occurs in horses *Occurs in Europe, Africa and Asia *…')
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*''Histoplasma capsulatum'' var. ''farciminosum''
== Introduction ==
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**Similar to ''H. capsulatum''
  
Epizootic Lymphangitis is a highly contagious, chronic disease of horses, donkeys and mules, caused by '''''Histoplasma capsulatum'' var. ''farciminosum''''', which is similar to [[Histoplasmosis|''H. capsulatum'']]. The disease is widespread in Europe, Africa and Asia. It has been eradicated from the UK but is still under the notifiable Diseases of Animals Act.<br>
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*Occurs in horses, donkeys and mules
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*90% occurs in horses
  
Disease is spread by direct contact or indirectly, e.g. through infected grooming equipment and [[Biting Flies|biting flies]]. Once established in a population it is very difficult to eradicate, which is not helped by the long incubation period. New cases can develop weeks or months after the infection appears to have been eradicated.
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*Occurs in Europe, Africa and Asia
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**Eradicated from the UK but is still under the notifiable Diseases of Animals Act
  
The disease affects the [[Lymph Nodes - Anatomy & Physiology|lymph nodes]], [[Lymphatic Vessels - Anatomy & Physiology|lymph vessels]] and [[Skin - Anatomy & Physiology|skin]]- mostly of the neck and limbs.
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*Chronic disease
  
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*Highly contageous
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**Spread by direct contact or indirect, e.g. through infected grooming equipment, [[Biting Flies|biting flies]]
  
== Clinical Signs ==
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*Once established in a population it is very difficult to eradicate
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**Long incubation peroid
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**New cases can develop weeks or months after the infection appears to have been eradicated
  
Ulceration and nodular lesions of the skin - mostly the neck and limbs as described above. Ulcers rupture, discharging blood-stained pus for several weeks. There will be swollen lymph nodes on physical examination and a typical lymphangitis appearance on the legs will be seen.
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*Affects the [[Lymph Nodes - Anatomy & Physiology|lymph nodes]], [[Lymphatic Vessels - Anatomy & Physiology|lymph vessels]] and [[Skin - Anatomy & Physiology|skin]]
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**Mostly of the [[Musculoskeletal System - Anatomy & Physiology#The Head and Neck|neck]] and [[Musculoskeletal System - Anatomy & Physiology#Limbs of the Domestic Species|limbs]]
  
Pulmonary signs can also be seen in some cases.
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*Causes ulcerative, nodular lesions
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**Dissemination occurs
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**Pulmonary disease can occur
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**Ulcers rupture, discharging blood-stained pus for several weeks
  
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*Oval or pear shaped cells
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**Double contoured
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**Dimorphic
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***Grows in the yeast phase at 37°C and in the mycelial phase at room temperature
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**Growth is slow, taking up to 8 weeks
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**At room temperature, thick-walled chlamydospores can be seen
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**Orgnaisms can usually be seen in swollen [[Leukocytes - WikiBlood|leucocytes]]
  
== Diagnosis ==
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*Can be stained using Gram, Giemsa, H & E and 10% Methylene Blue followed by Carbol Fuchsin
  
Clinical signs and history would lead to a presumptive diagnosis.
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*Enzyme-linked immunosorbant assay can be used to detect the fungi
  
Samples of lymph nodes and blood samples can be taken for diagnosis. The organism can be cultured and grows in the yeast phase at 37°C and in the mycelial phase at room temperature. Growth is slow, taking up to 8 weeks so is not ideal for primary diagnostic reasons. At room temperature, thick-walled chlamydospores can be seen. Organisms can also usually be seen in swollen [[Leukocytes|leucocytes]].
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*Life-long immunity follows recovery from infection
  
The organism can be stained using Gram, Giemsa, H&E and 10% Methylene Blue followed by Carbol Fuchsin and an enzyme-linked immunosorbant assay can be used to detect the fungi too.
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*Treatment included potassium iodide, [[Antifungal Drugs#Polyene Antifungals|hamycin]] and [[Antifungal Drugs#Polyene Antifungals|Amphotericin B]]
 
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**Vaccination has also proven to be effective
 
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**Injection of hyperimmune serum around skin lesions has been proven to be effective[[Category:Subcutaneous_Mycoses]]
== Treatment and Control ==
 
 
 
In countries where this disease is notifiable, slaughter of the equid is required by law. In countries where treatment is used, options include potassium iodide, [[Antifungal Drugs#Polyene_Antifungals|hamycin]] and [[Antifungal Drugs#Polyene_Antifungals|Amphotericin B]]. Vaccination has also proven to be effective in endemic countries.
 
 
 
Injection of hyperimmune serum around skin lesions has been proven to be effective.
 
 
 
 
 
== Prognosis ==
 
 
 
Life-long immunity follows infection, if the animal recovers.
 
 
 
 
 
{{Learning
 
|flashcards = [[Subcutaneous Mycoses - Flashcards#Epizootic_lymphangitis|Epizootic Lymphangitis Flashcards]]
 
}}
 
 
 
== References ==
 
 
 
Blood, D.C. and Studdert, V. P. (1999) Saunders Comprehensive Veterinary Dictionary (2nd Edition) Elsevier Science
 
 
 
Knottenbelt, D.C. A Handbook of Equine Medicine for Final Year Students University of Liverpool
 
 
 
Reed, S.M, Bayly, W.M. and Sellon, D.C (2010) Equine Internal Medicine (Third Edition), Saunders.
 
 
 
 
 
 
 
{{review}}
 
 
 
{{OpenPages}}
 
 
 
[[Category:Subcutaneous_Mycoses]]
 
[[Category:Dermatological Diseases - Horse]]
 
[[Category:Lymphoreticular and Haematopoietic Diseases - Horse]]
 
[[Category:Expert Review]]
 

Revision as of 13:34, 29 April 2010

  • Histoplasma capsulatum var. farciminosum
    • Similar to H. capsulatum
  • Occurs in horses, donkeys and mules
  • 90% occurs in horses
  • Occurs in Europe, Africa and Asia
    • Eradicated from the UK but is still under the notifiable Diseases of Animals Act
  • Chronic disease
  • Highly contageous
    • Spread by direct contact or indirect, e.g. through infected grooming equipment, biting flies
  • Once established in a population it is very difficult to eradicate
    • Long incubation peroid
    • New cases can develop weeks or months after the infection appears to have been eradicated
  • Causes ulcerative, nodular lesions
    • Dissemination occurs
    • Pulmonary disease can occur
    • Ulcers rupture, discharging blood-stained pus for several weeks
  • Oval or pear shaped cells
    • Double contoured
    • Dimorphic
      • Grows in the yeast phase at 37°C and in the mycelial phase at room temperature
    • Growth is slow, taking up to 8 weeks
    • At room temperature, thick-walled chlamydospores can be seen
    • Orgnaisms can usually be seen in swollen leucocytes
  • Can be stained using Gram, Giemsa, H & E and 10% Methylene Blue followed by Carbol Fuchsin
  • Enzyme-linked immunosorbant assay can be used to detect the fungi
  • Life-long immunity follows recovery from infection
  • Treatment included potassium iodide, hamycin and Amphotericin B
    • Vaccination has also proven to be effective
    • Injection of hyperimmune serum around skin lesions has been proven to be effective