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  Discussion on Treatment for Stringhalt post EPM
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New Member:
Arztlaw

Posted on Tuesday, Dec 27, 2005 - 3:13 pm:

Hi. I hope I am doing this correctly. I have a 12 yr old TB mare, diagnosed with EPM early summer, but I declined the spinal tap in the field for definative diagnosis, as being too risky. Put on Maquis for a month and "flu like symptoms" depression, I believe a fever, miserably alleviated but the duck like walk remains. Vet suggested a high fat, low starch grain with corn oil and 3000 IU's of vitamin e per meal, 2 x's a day.

Almost 6 months later, still walks like a duck, cannot trot. Now can gallop and canter but not as a big, fancy moving, beautiful horse that she was. Is there anything substantive, meaning meaningful, other than waiting for the passage of time that can be done? Thank you. Lee Arzt
Moderator:
DrO

Posted on Wednesday, Dec 28, 2005 - 6:27 am:

Welcome Lee,
What can be done depends on a correct diagnosis. How sure where you that the EPM diagnosis was correct? Also your second sentence above is hard to understand. Lastly can you better explain the "duck walk" that you currently are dealing with?
DrO
New Member:
Arztlaw

Posted on Thursday, Dec 29, 2005 - 2:39 pm:

Thank you for your quick response Dr. Oglesby. I think my reply email may not have registered, so I am summarizing here.

In this area (Central Virginia) 90% of all equines are exposed to epm so they screen test positive and mostly these are false positives. The only known definitive test I'm told is the spinal tap and in the field I am uncomfortable that the knowledge gained outweighs the risk of exposure.

My horse broker friend doubts the epm diagnosis as many of the symptoms of epm are similar to other diseases and epm is one of the diseases du jour. I went with the the Veterinarian's advise however and put Chilly on Maquis for a month and her miserable aspect, stumbling around, and possible fever abated, but her walk did not improve. At the outset, she did not know where her rear feet were. She became junior to a very omega animal (and the only other member of the herd).

Now she is bright and alert, full of energy and has resumed her bossy, cranky role in the very little herd. She is of the Northern Dancer strain and is a fairly dominant animal.

She can at times canter and gallop correctly, but not as beautifully and gracefully as before. She cannot trot at all. Sometimes when trying to canter or gallop she uses her rear legs in unity. Not a good thing usually.

Her walk is affected by temperature and other factors that I am not aware of. In general the problem is bilateral. Sometimes the symptoms look like they are stronger on one side though. In cold weather at each stride of the walk the leg is drawn straight up towards the body in a sort of cocking action as though she were planning to kick. She has to overcome what appears as a spasmodic action drawing the leg up to get it back down. In warmer temperatures the foot does not rise as high as in cold. At the beginning and end of a walk the spasms are less controllable than at the middle of a walk where she hopefully has gotten herself going. She has to try to canter to go fast but often the canter has the unity of the rear leg problem. The other day however she was pretty good at galloping around.

She was an unsuccessful race horse who raced 15 times and never won, but her family of horses requires great consideration of the personality of each to get them to want to win. When she knew she was home she did a little demonstration of just how fast she can run, which ended up with her coming off the fence and skidding to a stop nose to nose with me. }She is a character and one that I want to succeed at something. She is though the individual that put me in the ER and was fairly stressed after she basically caused my other horse to run over me. We are now both not in great shape and I am trying to figure out whether there is a way that she can be useful as a show horse/ trail horse/ broodmare, etc. Now she is a pet. Lee Arzt
Member:
Lilly

Posted on Thursday, Dec 29, 2005 - 4:37 pm:

Hi Lee,
I am not sure who your vet is or where you live in Virginia, but I also live in Virginia. I am encouraging all of my fellow Virginia horse owning residents to check out the EQ Case Report in the Jan 2006 issue of EQUUS. The article focuses on a group of horses living in Chesterfield, VA. All of the horses became sick and the the test on blood and spinal fluid pointed to EPM. It turned out to be Australian stringhalt caused by eating Hypochoeris radicata aka "false dandelion". The vet who did the diagnosis is Dr.Cupp - my friends say he's great.
New Member:
Arztlaw

Posted on Thursday, Dec 29, 2005 - 5:54 pm:

Hi Ann. I live in Hanover County and an currently using Dan Slovis of Virginia Equine as a vet. I have not asked him to come over lately as there have been no changes. Now most of the foliage is in hibernation for the winter. So for maybe a month or more the amount of forage from pasture has been little to none. I am concerned that you say that the spinal fluid pointed to epm. I thought that this test was definative? We have what appears to be dandelions in the pasture, which is of mixed greens and not at all purely anything. This was fine for keeping them fat and happy for two years. I will get the Jan o6 Equus. Thank you.
Member:
Lilly

Posted on Thursday, Dec 29, 2005 - 6:37 pm:

Hi Lee,
I hope I didn't scare you about the spinal tap. Here is the exact wording:
"The veterinarian drew samples of the gelding's blood and spinal fluid to test for Sarcocystis neurona, the organism usually responsible for EPM. Both samples showed that the gelding had been exposed to the protozoa, a finding which, combined with his obvious neurological deficits, pointed to EPM".

I just know that I don't pay close enough attention to what's growing in my horse's field and I suspect I am not the only one. If I know of a possible threat, I try to share the info. If I can help one horse....
Member:
Ryle

Posted on Thursday, Dec 29, 2005 - 10:45 pm:

False positives can occur on a spinal tap if there is blood contamination (and they have recently reduced the amount of blood needed to be found in a sample to consider it contaminated) and if the horse has been vaccinated with the Ft. Dodge S. neurona vaccine that was on the market under a conditional license. But, if you know the horse was vaccinated then you know you can't rely on the test and if the lab checks for contamination of the sample when they run the test. Ann, I wonder if any of those horses in discussed in the Equus article had been vaccinated (that causes postive results on both blood and CSF samples.)
As for the % of horses that test positive for exposure, there was research going on that showed that exposure rate was (in general) quite a bit lower than previously thought. And of those that are exposed, only a small percentage actually develope EPM. So even if your horse is exposed that doesn't mean that he will automatically get EPM.
Fever is not a sign associated with EPM, but it is associated with some of the other conditions that can cause the same sorts of neurological symptoms as EPM, such as EHV-1, EEE, WEE and WNV. Was your horse current on vaccinations and/or were those conditions tested for and ruled out? I would be more suspicious of one of those being the cause since you note that your horse had a fever.
New Member:
Arztlaw

Posted on Friday, Dec 30, 2005 - 12:26 am:

Thank you Ann. I am thinking I will get a way to identify false dandelion to see if I have it in my pasture. I would bet I do because there are a lot of dandelion like plants there. L
New Member:
Arztlaw

Posted on Friday, Dec 30, 2005 - 12:34 am:

Hi and thank you Cynthia. The mare was current on her vaccinations but may have missed her last ones as she had decided that she was a wild horse and did not want to be caught by anyone. She was not really trained post racing and had some issues with her handlers that lead to my decision not to try to use force to get her to comply. Ultimately that had to end when she became sick. I set up stalls in her run n shed and fed her there and closed her in, which accepted well. She still doesn't want to be caught in the field though.

It seems to me that she has a damaged nervous system regardless of the cause and maybe the need is to find a way to foster regrowth of the nerves if that is possible, or I guess just wait and see. Thank you for your comments. L
Moderator:
DrO

Posted on Saturday, Dec 31, 2005 - 8:40 am:

Hello All,
Lee there is little I can add to the above good advice and the usually excellent points made by Cynthia. I too after reading the history believe that EPM is not the most likely diagnosis but that herpes virus fits the overall pattern best but perhaps we are seeing several problems overlying each other.

We have an article on diagnosing the different causes of ataxia that is rather long and a despite my best efforts a bit technical, Equine Diseases » Nervous System » Incoordination, Weakness, Spasticity, Tremors » Diagnosing Incoordination, Ataxia and Weakness. It does illustrate the problems with diagnosing this type disease and you should give it a go to see if anything else looks familiar. The subtopic that I think best applies to your situation is Multifocal Diseases: Ataxia and Dementia Together. Though EPM is on this list it would be at the very bottom of my list of possibilities and I only put it there because it is reported in some case studies. Each of the diseases listed has a link to further explain diagnosis and possible therapies. Diagnosing EPM is explained in detail.

As to general therapies that might help nonspecific neuropathies you can consider high doses of vitamin E (at least 1 gm daily), checking the selenium status of your feedstuffs as VA soil is variable to low particularly towards the coast, and possibly corticosteriods if there is an ongoing noninfectious inflammatory process going on. We have more articles on VitE and selenium in the nutrition section.
DrO
Member:
Arztlaw

Posted on Saturday, Dec 31, 2005 - 2:40 pm:

Dr. O; Cynthia and Ann; Thank you all. I am about to check for this false dandelion, and am concerned about the possible diagnosis problem. Does this mean that the poor animal may still be ill, and that further symtoms are likely? Or does this mean that the damage is done and now we focus on trying to boost the body to rebuild the damaged nerves? Actually this Horse is getting her selenium from her 8 lbs a day of Triple Crown Low Starch feed, (I believe). One question is How many IU's of Vitamine E equals one gram? And is there a better way than buying 1000 IU capsules and emptying them? Lee
Member:
Arztlaw

Posted on Saturday, Dec 31, 2005 - 3:00 pm:

I have read the articles and do not feel that there is a clear fit for a basically appearing healthy horse, but for the stringhaltlike symptoms. She is frustrated by her disability but is otherwise functioning well in her setting. What to do??? Is this worth a trip to a vet school? Is this a wait and see?(with vitamine e?) L
Member:
Arztlaw

Posted on Saturday, Dec 31, 2005 - 4:48 pm:

Hi All; I have read the article in Equus and seen the pictures of false dandelion. I have quite a bit of this in my pasture. On the other hand, this plant is ubitquitous in this area and why would one or some of the horses in a herd get the symptoms but not others? The others might take longer but my feeling is that it cannot really be the plant per se, but perhaps something that is in some plants but not others, like a plant disease or infection. While now I want to get rid of this stuff, it also seems silly as it is everywhere and in all horse pastures around here. I always thought that a mixed pasture was fine but how can you get rid of this without getting rid of all broadleafed plants, not to mention how to do this safely for horses who have no where else to go?
Member:
Sully

Posted on Saturday, Dec 31, 2005 - 8:24 pm:

Hello Lee
This is just my thoughts. The horse that is affected might be the only one eating it or prefers to eat it and seeks it out. The other horses might avoid eating it.
Nancy
Member:
Arztlaw

Posted on Saturday, Dec 31, 2005 - 10:29 pm:

Hi Nancy
I have noticed that she is still eating the remains in the pasture rather than her hay to the extent she can, while the other horse is content with her hay. Complicated to deal with. Happy New Year to all. Lee
Moderator:
DrO

Posted on Sunday, Jan 1, 2006 - 11:10 am:

With the man-made d,l-alpha-tocopheryl, the most common form, 1 mg equals 1 IU. For more on this see Care for Horses » Nutrition » Vitamin E and Horses.

The Hypochoeris explanation seems unlikely, I would have expected the broadleaf weeds in the pastures to have died off by now in VA and the toxicity is reversible if it happened last summer: are you seeing this plant now in your pastures? I would love to see a clear photo of this if you do. If you think this is possible there is a treatment that works in 24 hours for this problem and is described in the article, Equine Diseases » Lameness » Diseases of the Upper Rear Limb » Stringhalt. There are no selective broadleaf herbicides and to get rid of this will require treating all broadleafs. However clover is easy to overseed after getting rid of the weeds.

The article also gives an interesting set of rule outs that you can pursue in other articles on the site. One of the statements in the article was particularly interesting: If proprioceptive deficits and ataxia are detected in a horse with stringhalt, peripheral neuropathy caused by EPM should be considered likely. While the bilateral nature of your problem argues against EPM I find this intriguing. The decision to refer this to the university will depend on whether you think this is well diagnosed and all that is possible is being done, if not, referral makes sense. But even under the wisest of neurologist the cause in these cases often remain unconfirmed and treatment is done off a rule out list of most likely diagnoses and often these are the remaining damage from encephalitis virus infections where the only real therapy is time.
DrO
Member:
Arztlaw

Posted on Sunday, Jan 1, 2006 - 1:11 pm:

Hi Dr. O; The reason I doubt the false dandelion theory is that the onset of the disease was quick in a situation that existed for a very long time and the apparently acute symptoms seemed to dissipate in the first 2 to 3 weeks of the Marquis treatment, leaving the stringhalt seemingly classical symptoms. The depression left as did the weakness and I believe the inability to sense where the rear end was. Is it possible that the drugs in Marquis could have been effective against a different disease, or do you think she recovered on her own?

Now I attribute the occasional banging of her rear feet on the sill of the run-in shed to the spasmodic action of her hocks. This has always been equally bilateral but sometimes is unevenly bilateral particularly in warmer temperatures when I think its the left leg that is not raised as high as the right. In that situation I am hoping the stringhalt symptoms are disapating, but no luck there so far.

The ability to canter/gallop returned in the following months, but no trot and no regular walk. Knowing that I am not a professional in this area, I would speculate that what ever the causation, the peripheral nerve damage is there but the cause is not. I am also thinking that weed killers are not effective in winter. I doubt that the few scrawny plants would be effective to harm her further. Also I cannot tell when they are very small whether they are real or false dandelions.
Here in Virginia we have spurts of warm weather in winter that encourages a bit of growth.

We have created habitat for small mammals and we definately have squirrels, rabbits, groundhogs, possum, raccoons, etc., not to mention deer. Wish to have fox but none on the property so far. This area is changing from rural to suburban and the animals have to have a place to go

I will read the article. L
Member:
Ryle

Posted on Sunday, Jan 1, 2006 - 9:38 pm:

Lee,
EPM usually has a more gradual onset of symptoms that are often missed at first because they are so mild. And when treating EPM, even with the cidal drugs, Marquis and Navigator, usually you don't get a great decrease in symptoms in the first 2-3 weeks of treatment (usually not even in the first month or two after treatment). In fact, generally around 10 days to 2 weeks into treatment with Marquis many people see a worsening of symptoms that is called a "die-off" due to the increase in inflammation caused by the die-off of the parasites in larger numbers as the drug reaches it's highest concentration in the CNS. According to Bayer, successful treatment with Marquis is an improvement of 1 level on the scale used to judge neurological deficit by 2 months AFTER finishing treatment with Marquis. So you can see that recovery from EPM is an extremely slow process.
Again, the things that you say make me really wonder if EPM is an accurate diagnosis--fever, rapid improvement even before finishing Marquis, etc.
It is possible for a horse to recover from some of the other neurological conditions even without treatment and this could be the case especially if you were also giving supportive care including anti-inflammatories which would have lessened the severity of inflammation in the CNS (and thus lessening the severity of symptoms) as well as reducing fever.
With any condition that affects the central nervous system, there is the chance of permanent damage that will leave some neurological deficit. This can be extremely slow to repair or learn to compensate for. Talking to a lot of owners of EPM horses I have found that they see improvement in their horse's way of going even a year after treatment.
You just have to be patient and go slow with any creature, human or animal) that is recovering from damage to the central nervous system. Hopefully you will continue to see improvement no matter what the cause was.
Member:
Arztlaw

Posted on Sunday, Jan 1, 2006 - 10:27 pm:

Thank you all. L
Member:
Arztlaw

Posted on Monday, Jun 26, 2006 - 10:54 pm:

As a postlude to this, I spent the time to find the dilantin in Canada to get a good price and a new vet to help with the prescription, based on the chance the stringhalt was caused by toxins in the pasture. Within a day or two of getting the meds, the mare started to change her stringhalt gait. As a result I did not give her the medicine but waited to see what happened. Over the past few months, now about a year after the onset, she is mostly better. Her trot is back and the stringhalt is just a sometime hitch in her gait. There appears to be no telling the etiology of the condition, but a good conclusion.
Member:
Djws

Posted on Tuesday, Jun 27, 2006 - 12:00 am:

Happy to hear that your mare is better.

I have a friend that resides in Midlothian, VA. She has 3 horses and is very concerned with the dandelion dilemma. Someone near her went through quite an ordeal with their horse before they discovered the problem was in their pasture (fake dandelions).

Hope you have continued healing!
Moderator:
DrO

Posted on Tuesday, Jun 27, 2006 - 7:01 am:

Excellent Lee, and thank you so much for keeping us informed. Just think, had the meds got there a few days earlier and you had started them we would be singing its praises.
DrO
Member:
Arztlaw

Posted on Wednesday, Jun 28, 2006 - 7:07 am:

This website is an excellent resource for all of us. Thank you for the good wishes. I would add that if the false dandilions were the problem, that most of our horses would be hooves to the sky, as these plants are everywhere. My elderly showhorse was not harmed by these plants, nor are all the others in the neighorhood. Maybe the plants get a disease, which is harbored by some of the plants and transmitted to the horses. Anyway, I think that this is a problem which is unsolved.
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