Tag Archives: Equine Diagnostic Services

Gut Check: A New View from the Inside

Researchers are testing an endoscopic camera, contained in a small capsule and placed directly into the horse’s stomach, to gather imagery of the equine intestinal tract. The capsule sends images to an external recorder, held in place by a harness.

Researchers are testing an endoscopic camera, contained in a small capsule and placed directly into the horse’s stomach, to gather imagery of the equine intestinal tract. The capsule sends images to an external recorder, held in place by a harness.

Courtesy, Western College of Veterinary Medicine

Traditionally, veterinarians’ and researchers’ view of the equine intestinal tract has been limited. Endoscopy (inserting through the horse’s mouth a small camera attached to a flexible cable to view his insides) allows them to see only as far as the stomach. While ultrasound can sometimes provide a bigger picture, the technology can’t see through gas—and the horse’s hindgut (colon) is a highly gassy environment.

These limitations make it hard to diagnose certain internal issues and also present research challenges. But the view is now expanding, thanks to a “camera pill” being tested by a team at the University of Saskatchewan, led by Julia Montgomery, DVM, PhD, DACVIM. Dr. Montgomery worked with a multi-disciplinary group, including equine surgeon Joe Bracamonte, DVM, DVSc, DACVS, DECVS, electrical and computer engineer Khan Wahid, PhD, PEng, SMIEEE, a specialist in health informatics and imaging; veterinary undergraduate student Louisa Belgrave and engineering graduate student Shahed Khan Mohammed.

In human medicine, so-called camera pills are an accepted technology for gathering imagery of the intestinal tract. The device is basically an endoscopic camera inside a small capsule (about the size and shape of a vitamin pill). The capsule, which is clear on one end, also contains a light source and an antenna to send images to an external recording device.

The team thought: Why not try it for veterinary medicine?

They conducted a one-horse trial using off-the-shelf capsule endoscopy technology. They applied sensors to shaved patches on the horse’s abdomen, and used a harness to hold the recorder. They employed a stomach tube to send the capsule directly to the horse’s stomach, where it began a roughly eight-hour journey through the small intestine.

The results are promising. The camera was able to capture nearly continuous footage of the intestinal tract with just a few gaps where the sensors apparently lost contact with the camera. For veterinarians, this could become a powerful diagnostic aid for troubles such as inflammatory bowel disease and cancer. It could provide insight on how well internal surgical sites are healing. It may also help researchers understand normal small-intestine function and let them see the effect of drugs on the equine bowel.

The team did identify some challenges in using a technology designed for humans. They realized that a revamp of the sensor array could help accommodate the horse’s larger size and help pinpoint the exact location of the camera at any given time. That larger size also could allow for a larger capsule, which in turn could carry more equipment—such as a double camera to ensure forward-facing footage even if the capsule flips.

With this successful trial run, the team plans additional testing on different horses. Ultimately, they hope to use the information they gather to seek funding for development of an equine-specific camera pill.

“From the engineering side, we can now look at good data,” Dr. Wahid explained. “Once we know more about the requirements, we can make it really customizable, a pill specific to the horse.”

This article was originally published in Practical Horseman’s October 2016 issue. 

EPM Tilter. What Do The Numbers Mean?

During my horse’s recent Lymphingitis flare-up, the vet advised that we run labs to test for Lyme and EPM due to his presenting symptoms (hind weakness, twisting his back leg at the walk/walking sideways I refer to it as- “Chance’s swagger”).  As I noted previously, Chance’s Lyme test revealed that he was at the beginning stages of an acute infection…yay for the labs at Cornell University for their amazing ability to give you more than a positive or negative!

A little history before getting to the EPM Tilter results.

About 2ish years ago, Chance was diagnosed with EPM (and one of the reasons opossums and I are not friends since they host the disease as do a few other culprits).  Chance immediately began EPM treatment- he received Protazil in his feed for one month. After hours of research I chose Protazil, although extremely expensive (if you order from http://www.drfosterandsmith.com they sometimes have promotions where you receive store credit for every $100.00 you spend…they did when I ordered and I got a “free” dog bed that my dogs adore), due to the decreased likelihood of Chance experiencing a “Treatment Crisis” (worsening of symptoms) and the ease of administration (other brands require the drug being administered 1 hour before eating or an hour after and so on).  Typically, EPM treatment is done for 30 days and, depending on the residual symptoms, some may require subsequent treatments.  While Chance’s symptoms improved, I wanted to ensure that we annihilated the disease and did another round of treatment but this time with Marquis.  At the end of two months, Chance’s ataxia was gone!

Fast forward to September 2016…Chance, just having a Lymphingitis flare-up, has been tested for Lyme and EPM. Lyme came back positive.  And….so did the EPM test..well, kind of.  Wonderful.  (See why I loathe opossums?)

Chance’s EPM test #2 on 8/30/16 (the 1st one was 2ish years ago) showed the following:

“Combined SAG 2,3,4 Tilter on serum= 1:2000”

So, what does this mean?

The test revealed that Chance had “positive, specific antibodies” detected in the blood work.  This means that he had EXPOSURE to S. Neurona, a causative agent of EPM.   Serum tilters range from <1:250 (negative) to >1:4000 (high positive).  S. Neurona (SarcoFluor) is one of two protozoa found in EPM infected horses, the other protazoa is N. Hughesil (NeoFluor). S. Neurona is most frequently seen, whereas N. Hughesil is not as common.

The vet ran another EPM test to confirm the findings in the 8/30/16 test.  The results showed that Chance had “Combined SAG 2,3,4 Tilter on serum= 1:1000.  Again, Chance showed EPM protozoa in the positive-ish range.

I initially had not seen the results but was told by the vet that he was EPM negative.  So when I asked for the test results to be emailed to me and saw the numbers I sort of freaked out…I emailed the vet to ask for clarification.  She explained,

“The EPM test shows that he was exposed to the organism in the first test we did which is why we did a follow-up test. Since his exposure level dropped from 1:2000 to 1:1000 this shows that he does not have the disease. There is no good one time test for EPM once they are exposed which is why we had to do the repeat to compare the two.”

While this explanation offered me comfort, I was confused…why does he have any protozoa in his blood if he doesn’t have EPM?

I spoke to another vet and she explained it in a bit more detail…I am hoping I am summarizing what she said correctly..

When a horse tests positive for EPM they either have an active disease or they may not.  However, when the test does from 1:2000 down to 1:1000 this typically means that the horse’s immune system is working correctly to fight the disease off- active or not.  EPM testing typically provides you with a % of the chance your horse has an active EPM infection, or at least if you send it to Cornell University.  For instance, lets say a horse gets the results back and it shows that they are “positive” or have been exposed to S. Neurona (one of the two EPM protozoa)…their results are  1:647.  This means that, after doing a bunch of adding and multiplying that this vet kindly did for me, the horse has a 60-70% chance of having ACTIVE EPM.  Meaning, he most likely would be symptomatic (ie: behavioral changes, ataxia, weight loss, difficulty eating, changes in soundness, and a bunch of other neurological symptoms).

My hunch is that Chance’s immune system was boosted because I started him on Transfer Factor (amazing stuff… more information can be found in some of my older posts) again as soon as his results came back positive for Lyme.

Here are the 3 EPM tilters that were run on Chance (oldest to most recent) along with his Lyme test results:

epm-2014

epm-test-results-8-31-16

EPM results 9-8-16 copy.jpg

lyme-titer-8-30-16