A disease caused by the mycotoxins produced by the fungus Stachybotrys atra (also called S. chartarum, S. alternans).


[affected.gif]
Animals most affected
Horses, cattle, pigs, sheep.


[etiology.gif] Etiology
A mould that grows, after prolonged storage, in black colonies on wet or damp hay, straw or bedding, and on stored feed. Poisoning is caused by ingestion of contaminated feed.


[toxic.gif] Toxicity
The mould produces satratoxins (L, D, F, G and H) which are trichothecenes, potent inhibitors of protein synthesis in mammalian cells.
   
Toxic doses in g of contaminated straw:
LD pigs 100
  sheep 171
  horses 220


[clinical.gif] Clinical features and lesions
Acute syndrome

Subacute syndrome
(From 2-10 days after exposure)
At the outset (8-10 days):


In addition:

Hoematological effects (which develop within 15 to 20 days after exposure):


Advanced stage with intensification of all the above clinical features. The disease is called alimentary toxic aleucia.

Chronic dermal effects (pigs)


[treatm~1.gif] Treatment


[labinv~1.gif] Laboratory investigations
Samples of straw which appear blackened as if with soot.


[case.gif] Case summaries
Thirty-two cows were fed silage made from ammonium-treated straw. At the start of winter the majority of the herd presented with starey coats and weight loss. Subsequent to earlier visits, the vet also noted an intermittent hyperthermia, but most significantly haematomas and bleeding from injection sites. Blood analysis showed a low haematocrit, a lowered white blood cell count (mainly of granulocytes) suggesting the possibility of a mycotoxicosis. The laboratory identified some satratoxins in the dung and soiled bedding. The animals' diet,
based on straw, resulted in the ingestion of large quantities of the toxins, and was responsible for the development of the toxic syndrome.