ned wrote:
"Mike Lyle" wrote in message
...
ned wrote:

snip

I had a discussion with a vet who held the 'subjective' opinion
that
ragwort was the easy excuse for bad equine management. He claimed
he
had not seen a case of liver damage which could solely be
attributed
to ragwort poisoning. He had seen cases (plural) where nibbling
of
creosoted stabling and rails, had proved fatal. And he also
reeled
off a list of other plants which would prove just as dangerous
(including bracken, deadly nightshade, hemlock, yew, privet -
these
were just the 'common sense' ones that I can remember). And let's
not forget mouldy hay and too rich feeding leading to laminitis
which can also prove fatal.

Ragwort is just the scapegoat.

That does seem to be sensible. Stock won't generally eat it if
there's anything else, though hay and silage is a different
matter.
But since it kills by causing cirrhosis of the liver, autopsy
can't
establish for certain that ragwort was or was not the cause.

I understand that the toxin accrues within the body over a
considerable period of time. It is not just one contaminated feed
that
causes the problem. Is there not a test which could identify the
specific accumulated toxin?

Apparently not: by the time the cirrhosis is fatal, its cause or
causes will have been excreted. (I don't think the body is often
_able_ to retain toxins for long, since they are generally
water-soluble.) My book may be out of date, of course: it's the 1978
impression of the MAFF _British Poisonous Plants_. It does, however,
mention a 1963 study in which microscopic examination produced some
distinctive cytological evidence: I don't know what happened -- and I
might not understand it if I did know!

Mike.