Re: RC: pigweed

[karen Clanin <kclanin@fix.net>]

At 05:43 PM 8/22/99 -0700, guest@endurance.net wrote:
>hutchings ihutch@jps.net
>Does anone have any info on pigweed.  Where i board they have found mass
doses of it >and my horse seems to be eating a lot of it. He has pasture
turnout all day and >stalled at night

The following is from:  http://vet.purdue.edu/depts/addl/toxic/cover1.htm
hope it helps. there's also a nice pic of the plant also.

also of interest might be: http://www.ansci.cornell.edu/plants/alphalist.html


karen clanin




33. REDROOT PIGWEED 

Amaranthus retroflexus 

(pigweed family)


TOXICITY RATING: High. The plant is quite common and very toxic. 


ANIMALS AFFECTED: Cattle and swine are the animals most likely to be
affected; goats and sheep can also be poisoned. 


DANGEROUS PARTS OF PLANT: Leaves, stems, roots.


CLASS OF SIGNS: Breathing problems, trembling, weakness, abortions, coma,
death.


PLANT DESCRIPTION: Redroot pigweed (fig. 33) is a large (to 5 feet tall),
coarse, annual with red stems and simple, egg-shaped, wavy-margined,
alternate leaves. The green, inconspicuous flowers are borne in short,
compact clusters along with green spines. Seeds are small, shiny, and
black. Fields, barnyards, and waste areas are the favorite habitats of this
weed.


SIGNS: Pigweed contains a nephrotoxin that causes kidney failure, and also
contains soluble oxalates and is capable of accumulating nitrates.
Therefore, toxicity can be due to any combination of these toxicoses.


Animals need to consume pigweed in fairly significant quantities over
several days before signs appear. Typically, onset of signs is 3 to 7 days
from the onset of ingestion. Animals will usually avoid pigweed if there
are better forages available. Common incidences of poisonings have occurred
when swine have been raised in confinement and are then turned out into a
pigweed-infested pasture in the late summer to early fall. Under these
circumstances, the swine consume large amounts of the plant quickly, with
5-90% of the animals becoming affected, with 75% or greater mortality among
the affected animals. Modern management practices have largely eliminated
this type of poisoning, but it can still occur. In cattle, pigweed
toxicosis resembles oak toxicosis. 


In affected animals, early signs include weakness, trembling and
incoordination. This progresses to an inability to stand and paralysis, yet
the animals may still be alert and able to eat. Near the end of the
clinical course, the affected animals may go into a coma, and have edema
under the skin of the abdomen and the legs, have a bloated abdomen, and
die. The course of the disease is approximately 48 hours and is primarily
consistent with kidney failure. Cases where animals consume smaller amounts
of plants over long time periods have not been well studied, but this is
also believed to cause toxicology problems. 


Treatment with herbicides may render pigweed even more palatable, therefore
make sure all treated plants are dead prior to introducing animals.


FIRST AID: If pigweed is being rapidly consumed, limit further access and
ingestion of the plants. A veterinarian will be able to provide supportive
care for the different toxicants contained in pigweed, but the animals may
still succumb to the nitrates, soluble oxalates or the kidney toxin.


SAFETY IN PREPARED FEEDS: Pigweed is not safe in hay or other prepared feeds.


PREVENTION: To prevent pigweed poisoning, do not allow animals to have
access to affected pastures, especially if the animals are hungry. Spray or
mow plants down, making sure they are dead before animals are on pasture.
Provide for supplemental feed if pasture quality is poor, since well-fed
animals are less likely to consume pigweed. 



=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
Ridecamp is a service of Endurance Net, http://www.endurance.net.    
Information, Policy, Disclaimer: http://www.endurance.net/RideCamp   
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=