What is Atypical Myopathy and can it Kill your Horse?

Atypical Myopathy is a fungus in the ground and it comes out in certain conditions, mainly when there has been heavy rainfall, a lack of frost and an increase in relative humidity for several days.
There is no known cure!
It has already caused the death of approx 8 horses in the Hawkes Bay area (NZ).
It is a specific acute rhabdomyolysis (breakdown of skeletal muscle) and its characterised by weakness, stiffness, recumbency and a high mortality rate following severe degeneration of particular muscle groups.
Its been around for approx 50 years yet no one knows much about it. It is thought to affect younger horses more  but one of the horses that has recently passed was nearly 20, so no horse is safe.
The owners of the horses affected were told the recommendations for prevention were to feed horses lots of hard feed to reduce the amount of grass eaten, also there was something about the hay not helping and possibly being part of the cause (i'm a bit unsure about this), not letting the grass get low and if it does remove your horses from all grass.
Clinical signs:
- sudden onset of pronounced muscular weakness and stiffness
- rare signs include depression, colic, anorexia, & can be similar to oesophageal obstruction and hindlimb stiffness
- affected horses are unable to stand and are often found lying on their side.
- sometimes the horses will stand with a ventroflexed head (head lowered and a bit tucked in)              
- sweating and trembling are frequently observed
- horses that can stand can only do so for short periods of time (minutes)
- when moving, stiffness is obvious
- has been evidence of severe pain and paddling movements of the limbs
- appetite remains normal or increases
- usually severely hypothermic (rectal temp <36.5 degrees celsius)
- heart rate normal or moderately accelerated
- rapid onset of laboured breathing
- urine is dark brown in colour
****Death can occur within 72 hours of these signs****
 
The person i know who has lost her two horses told me they found them in their paddock shivering uncontrollably, it looked like they had hypothermia. One was lying down in a puddle, but the other was standing. They found that the horses could only stay standing for approx 10 min, and while they were standing they perked right up, eating happily seeming fine (once the shivers had calmed down). But once they lay down they started to make rasping sounds because they couldn't breathe and after a while it got harder and harder to get them back up. They called out the vet who had no idea what the cause was, they even contacted Massy who said they had no idea.
Anyway the horses were getting to a point that they couldn't walk and had to be pushed around, one was also peeing blood, and the decision was finally made to put them down. This happened over approx 2 days.
An autopsy was performed and it showed the horses were suffering from liver failure, respiratory failure, and i think kidney failure. At the end of all this Massy got back in contact and said that they do know what caused it and they sent some info. Basically they said it comes out in certain conditions, effects younger horses, is a fungus, causes breakdown of muscle and there is no cure but there is a 20% chance of survival. They also said its been around for 50 yrs and there is not much known about it.
 
Since no one knows much including your vets who, as already shown, probably wont even recognise it, and the fact horses are dying of it NOW, Im sending this out to whoever i can to get the word out.
Please send to all your horsey buddies and keep an eye out!

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