Happy Anniversary

Today is the second anniversary of Fudge coming home with us.  And what a two years it has been.

Today is the second anniversary of me saying, “Honey, look at this.  Look at how he is eating his food.  That’s kind of funky.”  What I saw were symptoms of the acute stage of EPM.  I just didn’t know it at the time.

Today is the second anniversary of an equine disease that would occupy much of my time, and take me in a new direction.  Even if I didn’t want to go there.

I think back to the sinking feeling in the pit of my stomach when I rode Fudge the first time at home.  I knew the feeling under my seat.  I had felt it before with my EPM horse Charlie.  Deep down inside I knew that it meant trouble.  What were the chances of having two EPM horses from two different locations?  What really defies the odds, is that both horses showed many of the same deficits, and this lead to Fudge’s early diagnosis.  EPM can vary tremendously from one horse to the next.

From one horse owner to another:  I will NEVER purchase a horse again without it being tested for EPM.  I keep my horses for life, so this is not something that comes up very often at our house.  But it may come soon for you.  This is not a politically correct thing to say according to the AAEP.  Many vets will scoff at this idea.  But I have been down this road twice now.  I will not go there willingly again.

If you ask for an EPM test (Sarcocystis neurona antibody test) at a pre-purchase exam, you need to be aware of the consequences.  First, the vet will refuse to do this.  Be firm, you are paying the vet to perform what YOU want on the horse.  Insist, you will have to live with this horse for some time, and getting rid of an EPM horse is not easy.  Treating is costly.  The consequences dire.

There are also reasons that a horse will correctly test positive.  It takes some time, but you can sort it out.  In a pre-purchase exam, look carefully for any cranial symptoms.  Many times they are the first to present.  Second, AAEP always states NOT to test a non-symptomatic horse.  Why?  Because a horse that has been exposed to Sn can produce a titer that can be seen on a blood test.  The horse can clear the infection by itself, without drugs.  There are also tests that will cross react with other species of Sarcocystis that do not cause EPM.  Sorting out the subtleties of Sarcocystis can be achieved with careful testing.

A horse that is naturally infected, and clears the infection by himself will have a titer that rises and falls in a 6-8 week period.  This can happen often, depending on how frequently the horse is being exposed.   This can happen without symptoms.  Use the knowledge of the titer cycle to schedule the tests.

Utilize a test that relies on Sn Surface AntiGen (SAG)1, these tests will not give false positives.  Tests that rely on SAG2, 3, or 4 will cross react with both Sarcocystis fayeri and falcatula.  These protozoa cause muscle tissue cysts, not neurological disease, and cause many false positives on Sn antibody tests.  You have three choices for the SAG1 test: The SAG1 ELISA, the Peptide ELISA, and the Sn RAPID Assay.   The Peptide ELISA is the most complete, the 10-minute stall-side SN RAPID is by far the fastest.  Some vets are using the Sn RAPID Assay to screen in the field, and if positive, sending the blood for a Peptide ELISA.  If the horse tests positive on any Sn antibody test, retest the horse in 2 to 4 weeks.  You are looking for a fall in the titer, meaning the horse has cleared the infection by itself.  If the horse is still positive, wait and test the horse again, or move on to look at other horses.

Some of you are thinking, “Three tests?  Are you nuts?”  No, I am speaking from experience.  The cost of three tests is minimal compared to the heartbreak and cost of treating an EPM horse.  For most horses, you will only use one test, and it will be negative.  Consider this:  I have two full years and several thousand dollars into treating Fudge.  He had no ataxia at the time we picked him up, but he did have cranial symptoms.  Had the Sn RAPID been available at the time I bought him, I would have passed him by. 

It is always acceptable to add to a purchase contract that the horse will test negative for Sn antibodies.  It can also be added to a contract that additional testing will be performed, and the acceptance of the horse is conditional on the tests.  Word it any way you want.  Just don’t send a check without first checking the horse.

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One Response to “Happy Anniversary”

  1. Roxanne Says:

    I just wanted to take the time and say thank you for your blog. Less then I year ago I had to put down my best friend because of this disease. Now I am more cautious and a little more paranoid with my new horse. I agree fully that horses should be tested before buying.