Posts Tagged ‘relapse’

Relapse, Relapse, Relapse

Sunday, December 26th, 2010

In this day of immediate media, I should have posted July 20th.  Suffice it to say that one of the relapses was mine, in Lyme Disease.  With the number of changes coming to the EPM world, I’ll try to keep the blog more current.

I sent a Fudge blood sample to Pathogenes to enter him in a study.  This was a study for horses that had previously had EPM, but had been treated and recovered.  I was happy that Fudge had recovered to the point where I took him for his first lesson.  What I got back was that he was in the process of a relapse.  I had both a SAG1 ELISA and a Lymphocyte Proliferation Assay run on his blood.  It showed formation of a very low number of lymphocytes, and a slightly higher SAG1 titer.  Before I could get the diclazuril shipped to me, Fudge had symptoms.

The relapse came about 15 months after his initial diagnosis.  We do not know if this was a replapse or a re-infection.  We started Fudge on a mix of diclazuril, sulphadiazine, and pyrimethamine.  I got a prescription for three months of treatment.  I had previously used just diclazuril, but wanted to see if the S/P would help.  I did not like having to give the medicine on an empty stomach.

Fudge had a Mayhew score of 2.0 during the worst of the infection.  He certainly was unstable when trying to trim his feet.  He dropped much of his food and dragged his rear feet.  As the long summer months wore on, he slowly improved.  After 2.5 months of medicine, Fudge showed some worsening of symptoms.  These were subtle differences in the way he moved, but seen on a daily basis, I could see them.  He was dropping more food, which was measurable.  We sent another sample for tests.  Fudge was having a relapse while still on the medicine.

Anti-protozoal treatments kill or stop reproduction of the pathogens to a degree where the horse’s own immune system can kick in and finish the job.  Reading the drug inserts the drug only kills about 95% of the protozoa.  The horse has to eliminate what is left of the infection.  Fudge was not relapsing due to the drugs.  His relapse was a sign that his immune system was not able to fight even small numbers of the pathogens.

Pressured to Ride the Horse

Tuesday, August 4th, 2009

A friend and knowledgeable horseperson stopped by the other day.  We went out to look at the horses, and she was concerned over the muscle atrophy on Fudge’s rump.  She said, “You’re letting this horse go to waste!  He has no muscle on the rear.  You need to get on and ride, ride, RIDE.  Build that muscle back up.”

I tried to gently suggest otherwise, but she wouldn’t hear of it.  Fudge looks like he is in good health, he feels good, and isn’t in pain.  Why would I not ride him?  My friend was trying to help with what she thought was a simple problem; muscle atrophy caused by non-use.  

Fudge’s atrophy is caused by a lack of connection between the brain and the muscle.  The nerve damage limits the ability of the muscles to move correctly, or for the horse to know when to move the muscle.  This is a very different issue than loosing muscle from lack of use.  Understanding this difference is important to rehabilitating the horse.

Rehabilitation must first work on the connection between the brain and muscle, until the horse has control of that body part.  Giving the horse 24-hour turnout to gently exercise allows him to use the muscles as he is ready, and for longer periods of time.  Slow ground work exercises will also help the horse activate muscles in a safe way.  Until there is connection between the brain and the muscle, building muscle mass may not even be possible.

One article suggests that nerve damage can be repaired at a rate of 1″ per month, up to one year.  After that time, the window of opportunity to reactivate the muscle is lost, and remaining damage will be permanent.  If the horse had EPM for a length of time, the extent of the nerve damage may be too wide, and the window too short, for the body to repair.  There are also anecdotal stories of spontaneous resumption of muscle awareness two years after EPM.  The key is realizing that recovery is a slow process.

During the horse’s time-off, muscle atrophy will certainly occur due to lack of exercise.  The safety of both horse and rider must be taken into account when deciding to resume riding, even at a walk.  Don’t let someone pressure you into ridding the horse if they don’t understand the reason for the muscle loss.  If you begin riding the horse before he is able to comply with commands, you set the stage for stress and relapse.  A horse that has relapased will have a much longer rehabilitation time than one that is given time off.

Dancing the Two-Step

Thursday, July 2nd, 2009

Two steps forward, and one step back that is.

© Rich Chang 'Two-Steppin'

© Rich Chang 'Two-Steppin'

The IFAT blood results came back for Fudge, showing NEGATIVE to both S. neurona and N. hughesii.  Not just low counts, but NO counts.  That is very good news for Fudge, as he is not cycling into relapse.  It also means that the compounded diclazuril did it’s job, and the blood sample was clear of anti-bodies to the protozoa.

The results from the selenium test came in at normal, 0.22 on a range from 0.08 to 0.50.  He is not low in selenium, and that is not a cause of his neuro symptoms.

It does raise the question if something other than heat-related stress is at work giving him worse neurological symptoms.  Fudge has not been worked, trailered, wormed, vaccinated, or had a change in food in the past three weeks.  Three members of my family saw the changes, and the vet saw them.  He is not sweating excessively, and it has not been blazing hot here.  I believe we can rule out a number of the other possible neurological deficit causing diseases, based on history.  Could he have fallen in the pasture?  Possible.  I believe we are going to watch and wait before jumping into X-rays.  In the mean time, we’ll work with some TTouch exercises and desensitizing.

With EPM, it is often two steps forward, and one step back.  You never quit looking over your partner’s shoulder; never know what will cause another setback.

Stop the Merry-Go-Round – I Want to Get Off!

Friday, June 26th, 2009
CC JesusCM 'Carrousel'

CC JesusCM 'Carrousel'

It’s been that kind of a week.  Last weekend we noticed that Fudge was not turning on his haunches as well as he had been.  When standing to be brushed, his right rear leg was cocked out almost 90°.  Monday night he wasn’t really interested in dinner, so we took him out for a quick neurological test.  We considered that the symptoms might be heat related, but up until yesterday it had not been truly hot here.  Tuesday offered the same deficits.

The vet came out Wednesday to take blood samples, do a partial neuro exam, and to talk about a relapse.  We sent the samples to UC Davis for an IFA test for S. neurona, and a Selenium test to see if he is deficient (different than a mineral profile).  In the exam he had problems turning on the right rear, failed to move his right rear leg back into correct position when placed far out or crossed (proprioception), and was easy to pull of-center by the tail.  She agreed that he looked worse, and we decided to order medicine without waiting for the blood test results. 

Thursday morning we tried to order diclazuril.  It turned out to be an all-day affair.  The bottom line was that the compounding pharmacy only had enough diclazuril to make a 21-day supply, not the 60 days that we need.  They did not know when they would get more diclazuril, if ever.  I told them to send it, and I hoped that I would find another source in the next two weeks.

I emailed an EPM horse owner in Oklahoma, whom I knew had recently treated with diclazuril.  She put me in touch with her vet, who gave me the compounding pharmacy information.  Problem solved.  I’ll add the compounding pharmacy information to the Treatment page. 

For those wondering why I don’t just pick up a tube of Marquis, it’s about the strength and cost of the drugs.  Dr. MacKay at U of FL recommends using ponazuril (Marquis) or diclazuril at 7X the FDA dose for treatment of relapses.  That would equal one tube of Marquis PER DAY, for four days, then a regular dose for 28 days.  Add to that a sulfa combination, and you could be talking about $2000 of drugs in the first month, likely to be repeated for a second month.  The compounded diclazuril or diclazuril/sulfa/pyrimeth can be as little as $145 per month, for a 7X dose of diclazuril for the entire month.  Dad was right.  There is no money tree growing in the backyard.

EPM - it robs the horse of his grace and dignity…and robs the owners as well.

By The Numbers

Monday, March 2nd, 2009

55% Horses in the NE that have been exposed to the EPM protozoa

1-2% Of horses exposed to EPM will get an active infection

60% Horses that respond to drug therapy

10% Uncertain percentage of horses that fully recover

20% Horses that relapse within three years of treatment

Because there is no mandatory reporting for this disease, the figures are an educated guess by researchers.  I have seen statistics that indicate only 5% of the horses will fully recover.  What the statistics don’t say?  The 40% that don’t respond to drug therapy progressively get worse until they die or are euthanized.

The statistics are a compilation of percentages that have appeared in various articles, Equus Magazine, and ‘EPM: Managing Relapses’, Compendium Equine, Jan/FEb 2008.