SUBSCRIBE TODAY Smiley face  Get updates via email! 

We Are Flying Solo

November 6, 2014

Pt. II: What Every Horse Owner Should Know About Feed (And Botulism!)

In our previous post, my personal Triple Crown (TC) superhero had already gone above & beyond the call of duty...but she wasn't done stealing my heart.

Is it hot in here?
eventer79 (23 July, 10:34 am):  Thank you (yes, I believe we were in a competition to out-thank each other) so much for taking the time to type all that out!

In the spirit of self-education, would you be able to tell me if the feed is heat-treated at any point & if so, to a specific temperature?  I'm always trying to learn more about feeds & equine nutrition & wondered if processing included any types of those bacterial controls, particularly for things such as botulism?  I really have no idea.


It is painful for the biologist in me to admit, but I didn't know what I didn't know about the botulinum toxin.  My understanding was that horses were at risk primarily from dead/decaying animals in hay.  I don't feed round bales (greatest risk of Unidentified Dead Things Included), so I decided keeping an eye on my hay was sufficient, & Dr. Bob said that was fine.  So I have not traditionally vaccinated for botulism.

Enter Google:  a fantastic resource tool with the simultaneous ability to scare the shit out of you (a pleasure I shall naturally share with you!).  After I sent the above question, I realized I didn't even know if the toxin could be killed or anything about its life cycle.  Bad, bad biologist (to be fair, I determinedly avoid studying things you need a microscope for)!

Warning:  Science Geek-Out Imminent

Clostridium botulinum (all EIGHT types; horses usually suffer from Type B & C - we only have a vaccine for the former, humans from A, B, E, F, & G) is a fascinating, if unfriendly, bacteria.  The bacteria itself, along with its spores, offers little direct threat.  The problem occurs as bacterial cells die, releasing the potent neurotoxin that is botulinum.  Direct cell death happens with ingestion of live bacteria, or of spores, which germinate in anaerobic environments, create an overpopulation of cells...that then die.

C. botulinum under an SEM -- amazing!
Holy Crap, Are We All Doomed?

Fortunately, every system has weak spots.  Live C. botulinum perishes with the use of many disinfectants, including sodium hypochlorite (bleach, chlorine) & 70% ethanol (sorry, you can only have that if you are my co-worker or have your own TTB, formerly ATF, permit), & cannot survive if any oxygen is present in its microenvironment.

The botulinum toxin, a large protein, is similarly vulnerable:  sunlight will denature it within three hours, as will heat above 80C (176F) for 20 minutes or above 85C (185F) for five minutes (i.e. boiling; values vary slightly with toxin concentration & surrounding pH).  

But the spore.  Oh, the impressive spore.  Able to live 2-3 years, these babies can even germinate if damaged by extreme environmental conditions.  To ensure complete Spore-maggedon, you pretty much need access to an autoclave so you can heat them to 120C (250F) for a minimum of 15 minutes.

With that in mind, we return to the conclusion of our conversation -

TC Rep (23 July, 2:51 pm)Absolutely!  The pelleted portion of Complete is heated to 130 – 140 degrees (F) in order to form the pellet, but the rest of Complete is not.  We do use bacterial & mycotoxin preventatives in the feed, these function within the horse’s gut to bind & remove bacteria & mycotoxins before harm can be done to the gut, or if the horse ate or drank something else that was contaminated.

These precautions are for gram-negative toxins; botulism is a gram positive toxin:  the best way to prevent botulism is to vaccinate.  Hope this helps! Thanks!

Stacy Andersen800.451.9916
PO Box 220 | Mohnton, PA 19540
(someone give this woman a raise!)

The Conclusive Non-Conclusion

Needless to say, the boys just received their last round of the initial botulism vaccine series.  In the objective big picture, our risk of infection is still relatively low, but the 24 hours I spent staring out my bedroom window trying to decide if Encore looked like he was developing hind-end paralysis were...not something I care to wonder about again!

You may now consider yourself informed.  You're welcome.

However, this is the tip of the iceberg that is equine metabolism & nutrition.  My quest for TEH LEARNING is far from over! 
It's still true...


  1. Keep teaching us your wise waysss!

  2. Oh no, does this mean I now have to meet quality standards??? Dangit, talk about shooting myself in the foot! ;P

  3. Soooo... if I understand you right - you are you saying that a dead critter, who politely fell out of some hay before arriving at my barn, could have spewed out spores anyway, invisibly infecting a bale?

    And there would be no way to know until Val began paralyzing? Something I suspect him of periodically for no good reason? UNTIL NOW?? Excellent...

    (Thanks for the heads up - my vet had mentioned it but didn't go into detail. I thought it was soil borne for some reason - now I have a handle on the risk. :D)

  4. Something could have died in the hay field two years ago. However, the bacteria would have to have been present & reproducing at the time. If the toxin is already present, the helpful sun will take care of that for you. But if the spores are ingested & then successfully germinate (oh, and it's the right strain of the bacteria), then there can be infection.

    And yes, the spores are present in soil -- concentrations vary around the world, a particularly high-risk area is the true Mid-Atlantic: KY/MD/VA. This particular method of transmission is one that you can keep low on your radar screen unless there is a sudden spike of outbreaks in your (or your hay supplier's) area.

    And you are most welcome, I do my best to share my equine paranoia, due to which I am sure they are going to fall over & die on a daily basis. :D

  5. Will it make their wrinkles go away before it kills them?
    đŸ˜‚Sorry, couldn't resist!

  6. P.S. Chlorine dioxide (like White Lightning) kills spores, which is super helpful if your horse's hooves ever get Anthrax.

  7. ROFL, Frizz, if I hadn't been so exhausted when writing this, it totally would have included a joke about hey, at least my horse died with a smooth forehead!

    I have not had any issues with Foot Anthrax (LOL), but I'm intruiged by your allegation. Could you a worn-out woman a favour and share the link to that handy info? I got my data from CDC/WHO, so they didn't mention White Lightning (imagine that, ha).