Conference noted::equitation

    8 - 10 weeks is about normal.  People whose horses have lots of
    pasture and "clean" stable mates can get by with less often.
    
    My critters get tubed once a year and paste the rest of the time.
    I rotate the kinds of wormer I use.
    
        By the way, no horse is ever completely free of worms.  They 
    just get to an acceptable level.
    
    -maureen
    

    This is also my normal routine. Since I went to every 2 months,
    I have never had to scrape bot eggs off of any of my horses. Worming is
    very cheap insurance against parasite induced colic. I worm the same
    day the farrier comes, so it is more often in summer when the worms
    life cycle makes it easier for the horses to pick them up.
    Sandy
    

    
    I paste every 8 weeks.  Since my horses have histories of being
    terrible to tube, I have a fecal sample examined to make sure the
    pasting is doing the job.  If the fecal sample ever shows infestation,
    then I'll tube.  However, so far all the samples have been clean.

    
    Hi,
    
    I have never had my horse tube wormed.  He's absolutely a booger
    when the vet comes and the vet told me that it was no longer
    necessary to do this procedure.  The reason being that there
    was technically no difference in the wormers effectiveness regardless
    of the application technique.  He said that anymore, the vets
    out here only do tube worming at the owners request.
    
    Recently, Rail went through a very severe illness and we thought
    at first that it might be worms.  When Dr. Wallace tested
    the stool specimen, he said that it looked remarkably clear.  This
    is with at least 3 years of only paste and on a 3 month rotation.
    I rotate strongid with invermectin and benzelmine.
    
    Please bear in mind that I'm in a LOT dryer climate than you and
    I'm sure thats a major contribution.  
    
    good luck!
    
    jan
    

    re:- I agree w/ tube vs paste.
    
         We are on the 6-8 week schedule as well. A sample is taken
         in the spring. If clean we continue are schedule. Our vet
         recommended if the sample should ever prove positive, to worm
         every four weeks for the next three wormings, and at the next
         4 week worming, sample again. If clean, back to 8 weeks.
     
         She also mentioned to allow 4 weeks between last worming for
         sample.
    
         Dave'
    

    
    Thank to all!  it was very helpful, I knew I could count on you!
    
    Louisa

    Pasting every 2 months is normal.  You should also rotate which worms
    you paste for.  Most veterinarians will make recommendations of the
    best times ti paste fow what.
    
    Mary

    We worm just about every month, but rotate between ivermectin,
    Strongid-T, and Anthelcide-C.  We used to tube worm because we had one
    horse that was particularly sensitive to migrating larva which wormers
    didn't used to kill.  She would colic a lot because of it, but the tube
    worming helped the colic quite a bit.  The ivermectin now does a good 
    job on the larva, so we don't tube any more and she hasn't had colic 
    much at all since we've been using the ivermectin (we're still keeping
    our fingers crossed though!).
    
    						Jan

THE SHORT VERSION - Condensed from "The Chronicle of the Horse" Nov 29 1991:

Studies have proved ivermectin to be safe for young foals, and very effective 
against ascarids(roundworms), preventing lung and liver damage before it 
starts.

Trials showed that ivermectin was effective against the migratory third and 
fourth stage ascarid larvae in the foal's body tissues.  In 1989, the FDA 
approved use of ivermectin in foals under 4 months of age.  

Foals between 28 and 59 days of age were treated with ivermectin and none
of the foals showed any adverse effects.  The deworming completely
eliminated all third stage migratory larvae and all ascarids in the small
intestine.

The horseman can prevent the lung damage due to ascarids by deworming young 
foals even earlier than traditional schedules. Repeat treatment every 6-8
weeks until the foal reaches 1 year of age.  


THE LONG VERSION quoted from the magazine:

   The roundworm or ascarid (Parascaris equorum) is a troublesome parasite
in foals and young horses.  These white worms are the largest internal
parasites found in the horse and may grow up to 12 inches in length.

   Roundworms are usually found in the small intestines after they mature,
where a single female may lay a quarter of a million eggs per day.  The 
eggs are passed out with manure and usually must remain on the ground for
two or three weeks before maturing enough to become infective.

   When the mature eggs are ingested by a horse, they hatch and become
larvae - and migrate through the horse's tissues, developing into mature
adult form after the migration is complete.

   Adult horses have usually developed some immunity against roundworms.
By the time a horse is 2, his immune system can hinder the development of
ascarid larvae so fewer will be able to mature in his system.

   In a foal, the ascarid robs nutrients and can cause mechanical blockage
of the small intestine.  But the most common and extensive damage is during
the larval migration through the lungs.  Ascarids are the primary cause of
lung damage and cough in foals under 6 months of age.

   After the worm eggs are ingested with contaminated feed or water, the
newly-hatched larvae penetrate the intestinal wall and enter the blood
stream.  Within 48 hours the larvae reach the liver where they develop and
grow for about a week on their way through it.

   Upon leaving the liver, the larvae are carried by the bloodstream into
the lungs, where they pass through the small blood vessels and break through
the tiny air sacs and into the bronchial tubes.  Respiratory problems, nasal
discharge or cough, can be seen in the foal about three to four weeks after
he eats the ascarid eggs.

   After spending some time in the lungs and bronchial tubes, the larvae are
coughed up the windpipe into the mouth where they are swallowed, returning
to the digestive tract.  There they develop into adults and lay eggs.  The
interval between ingestion of the egg until the development of an egg-laying
adult is the prepatent period and takes about 2 to 2 1/2 months.  For this
reason fecal examinations for parasite eggs are usually negative until the
foal is nearly 3 months old.

   But a person should not wait that long before deworming the foal for
ascarids; they have already done their damage by the time they return to
the intestine.  Since horse pastures are usually heavily infested with
roundworm eggs, it is likely the foal has worms.

   Adult worms use up nutrients from the small intestine and may stunt the
foal's growth as well as making him rough-coated, emaciated and pot-bellied.
The irritation from the worms may give him diarrhea or collic.  A heavy
infestation can be fatal, and deworming him after he has a heavy infestation
can also be fatal - due to impaction and blockage from all the bulk of dead
and dying worms.  When treated with an organophosphate or piperazine dewormer,
a large mass of roundworms may suddenly die and cause impaction or gut 
rupture.  It's safer to deworm infested young horses with a drug that has a 
slower "kill rate" - like ivermectin or oxibendazole.

   When ivermectin first came out, advice to horsemen was to use it only in
horses over 4 months of age for two reasons:  First, not enough trials had
been done with the drug in young foals, and second, it was felt that the
drug was not effective enough against ascards in the very young foal.

   The latter opinion was partly due to the fact that dead ascarids did
not usually appear in the foal's feces following deworming with ivermectin
and egg counts didn't drop immediately.  This fact is the result of
ivermectin's mode of killing parasites, however.  They are not killed 
outright, as with other dewormers, but merely paralyzed.  They can't move
or eat so they eventually die.  But since it takes them longer to die, they
do not show up immediately in the feces and may not be obvious later, since
by the time they are passed out with manure their bodies may be somewhat
disintegrated.

   But further studies have proved ivermectin to be safe for young foals,
and very effective against ascarids, preventing lung and liver damage
before it starts.

   Trials lead by Dr. Thomas Klei of Louisiana State University and Dr.
Joseph DiPietro, University of Illinois, showed that ivermectin was
effective against the migratory third and fourth stage ascarid larvae in
the foal's body tissues.  Based on their results, the FDA approved, in
1989, use of ivermectin in foals under 4 months of age.  In the studies,
foals between 28 and 59 days of age were treated with ivermectin and none
of the foals showed any adverse effects.  The deworming completely
eliminated all third stage migratory larvae and all ascarids in the small
intestine.

   Now the horseman can prevent the lung damage due to migratory ascarid 
larvae by deworming young foals even earlier than traditional schedules,
repeating the treatment at 6- to 8-week intervals thereafter until they
reach 1 year of age.  After that, the deworming emphasis can be focused
more upon strongyles and their life cycles since ascarids won't be so
much of a problem.

    EQUUS had an article on deworming that I think is really out to
    lunch. We use a rotation of oxibendazole paste, pyrantel pamoate and 
    ivermectin. The oxibendazole is supposed to be the most effective of
    the "-zole" dewormers and, if you believe the ads they run in EQUUS,
    the only of the "-zole" family dewormers to which strongyles have not 
    shown resistance(yet). The article mentions pyrantel pamoate and
    ivermectin as also being drugs to which parasites are not resistant.
    
    Because of Seattle's mild climate, the recommended interval between
    dewormings is 4 to 6 weeks. We deworm monthly. We use ivermectin every 
    other month. The other months, we alternate between pyrantel pamoate
    and oxibendazole. We developed this program with our vet's advice so it
    may not apply to your situation.
    
    Here's the text of another nastygram I sent to EQUUS about the article:
        EQUUS,

        In a recent(EQUUS 170, December 1991) Medical Issues artice entitled 
        "What's New With Worms", you make misleading statements. I also feel
        that you have drawn illogical conclusions.

        The article reports that two recent studies show that only some 
        horses shed parasite eggs in their manure at a moderate to high rate.
        Based on that information, you state that it would be cost effective 
        and efficient to run a regular fecal analysis on each horse and
        deworm only as needed rather than at the usual 6-8 week intervals.

        Our equine veterinarian charges $8 for a fecal analysis. To deworm a
        1000-1200 pound horse, we pay about $4 for oxibendazole paste, $5 for 
        pyrantel pamoate and $8 for ivermectin. How can it save us money to
        pay $8 to find out we don't need to spend $4 to $8 on dewormer? How
        can it save us time to collect fecal samples and drive 20-30 minutes
        to drop them off at our veterinarian's office versus having UPS
        deliver mail-order dewormers to our door?

        You also state the parasite's development of resistance to deworming 
        drugs would be slowed by the "deworm as needed" concept. The studies
        you reported showed that perhaps as many as one out of every three to
        one out of five horses had to be dewormed MONTHLY. It seems to me 
        that the parasites in one of these heavy shedders would become 
        resistant even more quickly than on the 6-8 week schedule. Once the
        heavy shedders have resistant parasites, the rest of the herd will
        soon have them.

        So, it seems that the 10 year old advice to deworm frequently and to
        rotate dewormers still prevails.
         

    
    
    	Not to get off the subject but,... 
    
    	You mail order your wormer..?
    
    	Where.. where .. (that would be a great savings to me).

    jeffers... stateline... where are cheaper prices also..
    
    
    
    
    
    wendy o'
    

    Jeffers Vet Supply, Dotham, Alabama
    
    Stateline Tack, NH (forget the town-Nashua, Salem?)
    
    

    We get our paste wormer and vaccines(we do most of our own
    vaccinations) from Foster and Smith. They also sell dog vaccines(we
    also do most of our own canine vaccinations...can't buy rabies in WA)
    
    Their ordinary prices are about what I said in that earlier note. Some
    other catalogs have slightly better prices when they have specials or
    sales or if they use a particular product as a "come-on" or "leader"
    item. But, we haven't found another catalog with better prices than
    Foster and Smith that could provide EVERYTHING we use.
    
    The pyrantel pamoate(Strongid-T) liquid we use requires a prescription.
    The paste form does not. 
    
    We buy the liquid in quart jugs and use it for the dogs and horses. The 
    canine dewormer "Nemex" is the same drug in diluted form. Our vet told us 
    the dosage of Strongid-T to use for our dogs and we haven't used "Nemex" 
    since! The last time we bought it, the quart price for the pyrantel 
    pamoate liquid was about $78. Since you need 2 ounces for a 1000 lb horse, 
    I figured there were 16 doses in a quart bottle. That's how I got $4 for 
    pyrantel pamoate.
    
    I don't worry about the shipping charges on mail orders because the 
    shipping is usually less than the WA sales tax if I bought the stuff
    locally!