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  Discussion on EPM Diagnosis
Author Message
Member:
Rob10549

Posted on Tuesday, Jan 11, 2005 - 6:32 am:

Dear Dr. O,
My horse was diagnosed yesterday with EPM. I am concerned about the choice of drug as I have heard some unfavorable results with Navigator. I was wondering what your feelings were when comparing Marquis vs Navigator. Also, if my vet choses one over the other and I am not in agreement will it offend him to discuss the alternative drug?? And lastly, to what extent should I expect a reveral of symptoms and a resumption of ridablility? And how long does it take before you see any improvement? Thank you, Robin
Member:
Ryle

Posted on Tuesday, Jan 11, 2005 - 10:39 am:

Robin,
First, I've known several people now who have treated with Navigator for EPM and I would have to say that the results have not been good. 3 of the horses ended up being put down due to suspected adverse reactions to the drug and even the ones who did recover had mild to moderate adverse reactions that led to the horses not wanting to eat. Marquis has much less severe side effects. I would definitely NOT treat my horse with Navigator unless it was a last resort.
Take the time to check out the drug insert for Navigator (there is a link to it https://www.meadowherbs.com/navigatorvetinsertletter.pdf)and the one for Marquis (https://country:msds@www.compasnac.com/cvp/10/1040/1040039.htm)
You need to have a very accurate weight assessment when using either drug, so it's best to measure and calculate weight rather then depending on a weight tape otherwise you could be under-dosing. With Navigator it's also very very important not to overdose! However, some vets (including some of the university researchers) are recommending using Marquis at 1.5 to 2 times the labelled dose or using it as labelled but continuing treatment for 2 months; Marquis has a wide enough safety margin to do this.
You should also have your vet take a look at the proceedings from the Nov 2003 AAEP convention as it has the most current ideas on treatment all in one place. And remember that you or your vet can also consult with the doctors at the universities who are researching EPM. Those of us on the yahoogroups EPM support list have found them to be very helpful and willing to answer questions.
Most of the people I know who have treated EPM horses have seen continued recovery from the neurological symptoms for 6 months to a year or more. Some of their horses have gone back to being rideable even at competition levels and some are just big happy pasture ornaments. How well they recover is going to be dependant on how much permanent damage has been done in the central nervous system. How well and fast they recover has also seemed to be closely related to having a slow recovery process and not being pushed to work. Many of the horses who's owners insisted on working them (either lunging or riding) too soon after being treated have had a recurrence or worsening of neurological symptoms or even a full relapse which required repeated treatment. Besides the fact that trying to lunge or ride a horse with neurological impairment puts both of you at risk for an accident. SLOW is the key!
As for how soon you might see improvement, with the use of NSAID's, many people see improvement right away, probably due to the fact that inflammation in the central nervous system accounts for part of the neurological deficit. With both Navigator and Marquis, people often see a worsening of symptoms sometime around week 2-3 of treatment and the use of NSAIDS can help lessen the severity of symptoms with this. But it's often a "2 steps forward, 1 step back" sort of thing with EPM...some days are better and some days are worse. If your horse feels better and is very active one day, he's likely to be more "off" the next. Keeping a journal will help you see where the improvements are.
To talk to other people who have treated their horses for EPM, check out https://groups.yahoo.com/groups/EPM and join the list.

Good luck,
Cindy D.
Moderator:
DrO

Posted on Wednesday, Jan 12, 2005 - 9:26 am:

Hello Robin,
We have a thorough review and comparision of both products including safety studies and the drug inserts in our article on EPM associated with this forum. Large studies of horses have not found the drug as toxic as Cindy's experiences suggest. However it is more toxic than the other recommended therapies, see the article for more.

I have tried to summarize the prognostic information in the article based on treatment and severity of symptoms. The article also has most of the information updated with the latest information on treatment, including the 2003 AAEP lecture. I have converted the Scientific Reports section over to our new format of providing a link that loads the latest posted scientific reports at the National Library of Science and Medicine. This has greatly decreased the size of the article and made it easier to load.

If you cannot discuss the drugs used and have some input with your veterinarian about the treatment of your horse, I suggest you get another vet. He should be very open to your concerns and thoughts.
DrO
Member:
Rob10549

Posted on Saturday, Jan 15, 2005 - 8:07 pm:

Thank u for responding. My horse started Marquis yesterday along with bantamine for the first 5 days. I trust my vet but also contacted the Chief of Medicine at Cornell to see how they treat horses with EPM. I am adding vit e, 5-800IU as well as Probios. He will be treated for 2 months. So far he seems abit subdued but he's still able to go out in a medical paddock for a short time. He has other complications, and is on antibiotics and cough medicine as one of his lungs sounded full and he was coughing at the walk. Strangely enough I had written to you Doc several times in the past couple of years about his skin balding at the girth accompanied by nodes. This was never diagnosed and clearly not from girth irritation b/c I have not ridden him in 3 mths due to a rear leg suspensory. My vet thinks that the suspensory could have indirectly been caused by the EPM as neurological deficits early on may have accounted for an overcompensation while being trained. The skin too, he surmises may also be related as now the nodes have changed to lumps in the last week or two as I saw the EPM symptoms increase. Then yesterday my farrier went to shoe him and found that one back hoof looked like white line disease might be forming with a portion of wall missing. He has me treating that with iodine DrOps daily. Needless to say I am in a complete panic and depressed watching my horse seemingly slowly self destruct. To top all this off, the day my vet showed up to DrOp off the Marquis, one side of my horse's neck looked like it had hives but yet upon touching it there was nothing there. Now today the other side has the same exact appearance. My vet ran his hand over the neck but didn't seem concerned but really didnt address it. Would EPM destroy the immune system so that my horse would have skin and hoof issues? And I do not know what to make of his neck. The neurological symptoms are not horrible, he falls in while walking and when his tail was pulled on a straight away the deficits were there but not hideous. Even if he makes it through this horrible disease I still need to rehab the suspensory. My vet said that if there is going to be resolution to the neurological deficits I'd see it in the first three weeks. Any input on any of these issues would really help me. Thank you, Robin
Member:
Ryle

Posted on Saturday, Jan 15, 2005 - 10:16 pm:

Robin,
It's common to see an improvement in the first few days that a horse is on anti-inflammatories due to the decrease in swelling in the central nervous system, but EPM is generally a rollercoaster ride--some days are good and some are bad. It's also common to see a marked increase in the severity of symptoms around week 2-3 of treatment with Marquis, commonly called a "die off". You need to have Banamine available around that time so that you can give it to him when the symptoms start to get worse. If the symptoms get really bad, your vet can give IV DMSO to decrease the inflammation. Allowing the inflammation in the spinal cord and/or brain to get out of hand can cause more damage to fragile tissues.
EPM doesn't destroy the immune system. It occurs when the immune system is already compromised. Normally horse's bodies can deal with the protozoa that causes EPM and they never get to the central nervous system to actually cause this disease, but if the immune system is compromised then the body just isn't able to clear the protozoa and prevent it from getting to the central nervous system to do damage.

Good luck,
Cindy D.
Moderator:
DrO

Posted on Monday, Jan 17, 2005 - 4:00 pm:

No, EPM does not have an effect on the immune system but there is some discussion about horses immune status and why they develop EPM. While Cynthia expresses a common sentiment there is at least one experiment where horses immune systems were compromised with corticosteroids and they were exposed to EPM and they did not develop the disease at any greater rate than the controls. We do know the number of organisms they are exposed to effects the chance of getting disease. As Cynthia stated earlier there is a feeling stressed horses are more prone, but currently there are more questions than answers.

3 weeks is a little short to draw any conclusions but it sure would be a good sign if you did. I cannot see any relation to the nodules on the girth, what did your vet say the relation was?
DrO
Member:
Rob10549

Posted on Thursday, Jan 20, 2005 - 10:37 am:

Hi Doc,
Thank u for responding so quickly. My vet thinks that perhaps the EPM compromised his immunity leading to the skin changes. He's coming back in three weeks to reevaluate my horse. We finished the banamine two days ago and my horse seems fine. Yesterday I watched him walk out to his medical paddock, a very short distance, but didn't see any sign of the neuropathies. Thank goodness my horse is coping well with being cooped up for so long. How would I know that a die off is occurring? What signs would be obvious? I am treating the skin with animax which seems to be helping. Also, what is the significance of heat in the suspensory branch while healing? Sometimes I feel the slightest bit of heat at the thickened suspensory. Should I be concerned on a daily basis? Thank you. Robin
Member:
Ryle

Posted on Thursday, Jan 20, 2005 - 10:50 am:

Robin,
"Die off" signs are worsening of the neurological symptoms. With some horses it's not very severe, but some horses will get markedly worse to the point of even going down. Talk to your vet about having Banamine on hand to use in case your horse has a really bad time during the "die off" phase.
Good luck with this guy.
Moderator:
DrO

Posted on Thursday, Jan 20, 2005 - 7:14 pm:

As Cynthia states we think the die off causes a temporary worsening in some horses. Though this is conjectural it is often observed that following the begininng of treatment some horses temporarily worsen.

Sensing increased heat is a bit of a mix bag in my experience with clients. Often they sense the normal variations of the temperature of the leg as significant and remember to always compare with the opposite leg. Without increase swelling or lameness slight changes in temperature are usually not significant.
DrO
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