EPM flare after routine vaccinations

[DownYonder]

Questions for those with EPM horses that were treated successfully and returned to work but later experienced another EPM recurrence:

1. How long after treatment finished did the relapse occur?
2. Was the horse on a low dose preventative (such as Decoquinate) after treatment? If so, how long after finishing the preventative did the relapse occur?
3. What time of year did the relapse occur?
4. Most importantly - Did the relapse occur within 60 days of routine vaccinations? If so, which vax were given and which brand(s)?

[knic13]

Following. My EPM horse is back to light work but has not been vaccinated since his initial dx.

Did your horse relapse after vaccinations while on decoquinate? If so, what is the preventative dose you were using?

[dotneko]

Yes on the relapse after vaccinations. We did them slowly, but still saw a recurrence of symptoms. Was on a low dose of the cocktail. Had two relapses. In spring and fall as I recall. Don’t remember the brands or sequence of vaccs

[goodhors]

Wow, news to me they have an EPM vaccination!! What is the product being used to prevent EPM? Is it a new invention?

Our Vet believes most Michigan horses are carrying the protazoa, just have not had stresses to allow the escape into the body yet. His own herd of Arabs all tested positive years ago, when MSU was looking for a “clean herd” to test against their group of positive horses. They never did find a clean horse group for the study.

We had an EPM horse who was treated successfully with Marquis, years ago. He was caught extremely early, Vet said he never would have guessed he had EPM after doing body tests, watching him move. We knew the horse well, he just wasn’t himself in moving or crabby attitude. We started the Marquis anyway, Vet promised visible, mental changes in 7 days if it was going to work. It truly did cause an attitude change, better moving, in that short time. He fully recovered with some special exercising, therapy riding, after the full course of Marquis. Horse was as good moving as ever before.

Horse was 18 at the time, never relapsed, used ridden and driven all the time until his death about 6yrs later.

[dotneko]

Not a vaccine for EPM. I believe OP is questioning whether EPM horses have relapses when given other vaccines like tetanus etc.

[DownYonder]

To clarify - I was referring to routine vax such as EWT, rabies, and WNV, as well as flu/rhino and strangles.

My horse is currently having his third relapse since initial diagnosis in Nov. 2011. The first relapse wasn’t diagnosed until Feb. 2018 but he had been progressively “iffy” all fall and into the winter. He is now having another recurrence that seemed to begin in Oct. In all three cases, he started getting NQR in the fall and worse over the next few months. The last two bouts began within a few weeks of his fall vax, and I believe the initial bout also happened not long after fall vax. He is super sensitive to vax and we generally break them up so he isn’t getting everything at once but he got hit with Vetera Gold in a few months ago due to a miscommunication between the vet and her tech. And it was within a few weeks of the Vetera Gold that he started showing pretty obvious circumduction of the hind legs and other troubling symptoms such as toe-dragging.

As for preventatives–we usually keep him on Decoquinate powder after he finishes Orogin treatments but he finished his last round of Decoquinate in June and was doing great up until October. We are now pretty darned certain that vax are triggering his flare-ups. I think he gets through spring vax okay because he has been on Decoquinate over the winter, but comes off of it in early summer so fall vax overwhelm his immune system and he can’t fight the protozoal infestation.

He just started Orogin this morning and we will follow up with Levamisole/NeuroQuel tabs and then Decoquinate tabs. Then we will recheck and see how things look but I am guessing he will end up staying on Decoquinate powder.

And no more vax other than rabies and strangles!

[ASB_Stars]

If you challenge the immune system, you give the EPM an opportunity to take another run at your horse. I first dealt with EPM long before there were any drugs approved in this country for it. The drugs That are available by the way, all have varying issues.

I’m fairly well convinced that you do not ever rid a horse of EPM once they have had a full-blown case. You simply drive the protozoans back, Try to support the immune system anyway that you can, and hope that the horses own immune defenses will actually be able to bring them back to a state of health.

As far as I’m concerned, every time you give a horse a vaccination you are challenging their immune system. If they’re right on the bubble trying to fight back the EPM, you can alter that balance and cause them to relapse. I would be extremely circumspect about what immunizations you absolutely must to give a horse who you know has a compromised immune system

[DownYonder]

Thanks folks for your input. ASB, I also tend to think that EPM is never truly eradicated and horses can and do have flare-ups throughout the rest of their lives. Not only are many horses constantly being re-exposed–particularly when opossum activity is high–but stress can trigger protozoal blooms.

My horse is not in a particularly stressful situation but the barn has woods and creeks near it that harbor many opossums as well as other wildlife such as raccoons that could be carriers. It is a full training barn and horses occasionally go off property for shows, clinics, trail rides, etc, plus there are outsides horses there periodically for clinics, so spring and fall vax have been required protocol. If he gets past this current bout, I will no longer allow him to have anything but strangles and rabies vax. We have boosted his Vitamin E intake and also put him on Immune Plus, so we will see if he can recover enough to go back to work. Praying for a miracle…

[JB]

@DownYonder

I will no longer allow him to have anything but strangles and rabies vax. We have boosted his Vitamin E intake

What’s his normal E intake (counting all supplements)? Many EPM horses need to stay on relatively high amounts for life, 5000-8000IU, give or take.

I would make sure he also gets a tetanus booster yearly - that’s a bit of a different type of vaccine, and horses are so susceptible to tetanus.

[mroades]

Down Yonder I had one like that. After it happened twice we put her on decoquinate for twenty days, and gave her the vax at the ten day mark. Worked for her.

[DownYonder]

@JB

What’s his normal E intake (counting all supplements)? Many EPM horses need to stay on relatively high amounts for life, 5000-8000IU, give or take.

I would make sure he also gets a tetanus booster yearly - that’s a bit of a different type of vaccine, and horses are so susceptible to tetanus.

Yes on the tetanus vax. As for E intake, I am not sure. I thought he was getting supplemental E, but I have not been there much the past 4-6 months due to life circumstances. I have not been billed for E so I guess he hasn’t been getting it. We have just put him on Elevate WS as well as an immune booster and I am ordering Vitamin E in bulk to give him after he finishes this bottle of Elevate.

[DownYonder]

@mroades

Down Yonder I had one like that. After it happened twice we put her on decoquinate for twenty days, and gave her the vax at the ten day mark. Worked for her.

Thanks. We are going to remove him from the schedule for routine vax and do only rabies, tetanus and strangles. I wouldn’t even do strangles since he doesn’t go anywhere. But other horses go off property periodically and we also have horses trailering in for lessons and clinics, so strangles vax is mandatory.

[Janet]

If it is happening in October, it COULD be related to day length rather than vaccinations. Try doing the vaccinations significantly earlier or later to see if it makes a difference. Especially if the spring shots don’t cause problems.

[dotneko]

Make sure the Vit E is natural not synthetic. Mine was 10000 IU daily.
Also, when he relapsed, we started with Banamine, DMSO and prednisone. Seemed to help.

[goodhors]

Thanks for clarifying that Donetko.

We gave our vaccines a week apart, one at a time. No big combination shots. Horse never reacted to them in any fashion. It takes longer to work thru them all this way, but we do not get reactions or problems either. We give our own shots so this method is not difficult or expensive to use. He was not getting any extra Vit E, or other meds…

While I believe we got rid of the EPM for a short time with the Marquis, he was probably contaminated, an EPM carrier again, after grazing in the pasture. He never exhibited any sign of EPM again in his career as a performance horse.

He was under a lot of stress the year he showed signs, which we think lowered his ability to contain the protazoa. After treatment, geting back to work, he seemed more relaxed with his new life changes, not stressed. He was a good traveler, accepting of many new situations he was exposed to as a single horse, instead of travel with barn friends.

[DownYonder]

@Janet

If it is happening in October, it COULD be related to day length rather than vaccinations. Try doing the vaccinations significantly earlier or later to see if it makes a difference. Especially if the spring shots don’t cause problems.

Interesting you say that! His relapses always seem to start in mid to late October and a few weeks after we switch from night to day turnout. He goes from being out from about 12 hours overnight, to 4-5 hours turnout in the morning. I have commented to both my vet and my trainer about how it seems related to the change in turnout time.

I have been thinking it had to do with the amount of time he was out, but am now formulating this hypothesis:

Opossums are most active at night, but they generally try to avoid pastures with horses in them and will find other routes such as between pastures, etc. So horses aren’t being exposed at night, but when they are on day turnout, the opossums can travel the pastures at will (they sometimes drink out of the outside water tanks). Horses go out in the morning, and so are at risk from exposure to fairly fresh opossum feces.

Add in the fact that grass is dying off in the fall and therefore and losing nutrients. There is no vitamin E in hay, so horses that are not getting supplemental E are at increased risk of an EPM outbreak.

What are your thoughts on how length of day ties in to that? Because grass is dying off? Or other factors?

[DownYonder]

@dotneko

Make sure the Vit E is natural not synthetic. Mine was 10000 IU daily.
Also, when he relapsed, we started with Banamine, DMSO and prednisone. Seemed to help.

Yes, it is natural. And the one I am ordering has 8,000 IU per recommended daily dose.

[knic13]

@DownYonder

Interesting you say that! His relapses always seem to start in mid to late October and a few weeks after we switch from night to day turnout. He goes from being out from about 12 hours overnight, to 4-5 hours turnout in the morning. I have commented to both my vet and my trainer about how it seems related to the change in turnout time.

I have been thinking it had to do with the amount of time he was out, but am now formulating this hypothesis:

Opossums are most active at night, but they generally try to avoid pastures with horses in them and will find other routes such as between pastures, etc. So horses aren’t being exposed at night, but when they are on day turnout, the opossums can travel the pastures at will (they sometimes drink out of the outside water tanks). Horses go out in the morning, and so are at risk from exposure to fairly fresh opossum feces.

Add in the fact that grass is dying off in the fall and therefore and losing nutrients. There is no vitamin E in hay, so horses that are not getting supplemental E are at increased risk of an EPM outbreak.

What are your thoughts on how length of day ties in to that? Because grass is dying off? Or other factors?

The EPM Protozoa is very resistant to environmental conditions, so it isn’t a matter of how “fresh” the opossum contamination is when the horse comes in contact.

[JB]

@Janet

If it is happening in October, it COULD be related to day length rather than vaccinations. Try doing the vaccinations significantly earlier or later to see if it makes a difference. Especially if the spring shots don’t cause problems.

Interesting! I’ve never heard of daylight length related to EPM - do you have any literature for that?

@DownYonder what day/month were the Spring vaccines given, where you didn’t get a flare? Roughly 6 months apart Spring and Fall, daylight hours are the same-ish. But you said he had also been on Decoquinate Winter-early Summer, so that throws a wrench in things.

[DownYonder]

@knic13

The EPM Protozoa is very resistant to environmental conditions, so it isn’t a matter of how “fresh” the opossum contamination is when the horse comes in contact.

Yes, I thought about that later in the day and realized I should have clarified my comment. 1) Opossums are more active at night; 2) opossums try to avoid occupied pastures if possible; 3) horses on night turnout are therefore less likely to be exposed to opossum activity; 4) day turnout puts horses at higher risk of exposure because the opossums are more likely to frequent the unoccupied pastures at night; 5) night after night after night of unfettered access to unoccupied pastures gives opossums plenty of opportunities to “seed” the pastures with feces.

So you are right, it may not be a matter of the freshness of contamination but rather the amount.