Is deworming horses leading to chronic inflammation and metabolic syndrome?

Posted on: September 1, 2012

Editor’s note: When I wrote this post, I was looking for all possible factors that might be causing my horses’ laminitis. I no longer think lack of worms plays a role. But the post is still interesting, and I am leaving it up for now.

In the span of one week, I read two articles in which medical professionals praised the power of worms to regulate inflammation in humans. Experts in “The New York Times” and on “The Huffington Post” say the lack of worms in people in developed nations may be what is causing chronic inflammation, and this inflammation may be the source of such baffling diseases as autism, asthma, rheumatoid arthritis, inflammatory bowel diseases, multiple sclerosis and metabolic syndrome.

They point to the fact that these diseases don’t exist in undeveloped nations where worms and infections are the norm.

It appears the worms are well-known for limiting inflammation.

“The Huffington Post” suggests that a lack of worms leads to “immune system idleness,” resulting in the immune system going on the offense, leading to automimmune disorders that account for “a huge portion of the disease burden in modern societies.”

According to “The New York Times,” at least a third of autism cases are attributed to inflammation, and a Denmark study indicates that inflammation in the mother is to blame for autism in these children. Experts theorize that, if they can fix the inflammation in the womb, they can get rid of those cases of autism because the inflammation won’t interfere with fetal brain development. A Swiss study using mice backs up that theory.

While some doctors are looking at drugs and probiotics as a therapy, Dr. William Parker at Duke University is simply restoring parasites in people, according to the article. These are worms developed solely for the purpose of correcting the wayward, postmodern immune system. And a trial is under way at the Montefiore Medical Center and the Albert Einstein College of Medicine in New York testing a medicalized parasite called Trichuris suis in autistic adults.

Dr. David Katz, M.D., wrote the article in “The Huffington Post,” and he says the use of probiotic bacteria in capsule form as a therapy for conditions such as irritable bowel syndrome is increasingly routine, and he makes extensive use of probiotics in his office. He says the use of therapeutic parasites is not yet routine, or even routinely accessible, but there might be some movement in that direction.

Where does that leave us with horses? I immediately searched for some sort of scientific revelation in the horse world that our endless deworming was doing more harm than just making worms resistant to the dewormer. What I found was well-written papers by top vet schools in the last few years still encouraging people to deworm, though in a more organized fashion.

But what is this deworming doing?

We know that horses that won’t gain weight often are examined for worms. Now I’m wondering if that inability to gain weight is a bad thing. The wormy horse’s body may be working perfectly.

Maybe worms aren’t the enemy.

Still, a recent study in the UK indicated that deworming reduced the risk of a horse developing laminitis. According to The Horse, which quoted Claire Wylie, PhD, MSc, BVM&S, a veterinary epidemiologist at Rossdales Equine Hospital, in Newmarket, England: “Compared to horses wormed every one to six months, horses that had been dewormed in the past four weeks had a reduced risk of laminitis; horses that had not been dewormed in the past six months to a year were 2.5 times more likely to founder; and horses that had not been dewormed in over a year or never were 11.3 times more likely to founder. ‘We don’t know why this is,’ Wylie said, ‘but it could be due to many things, such as a novel effect of anthelmintic drugs, an association between laminitis and gut function, or maybe it indicates better-cared-for horses (are less likely to develop laminitis).'”