As a relatively unencumbered (currently no pets, and a house in suburbia) horsewoman, I find myself farm sitting regularly. I enjoy taking care of someone else’s animals and making sure they all remain healthy and happy while their owners are gone. Murphy’s Law generally insists that something go wrong, however, with at least one of the horses/dogs/cows/cats/fish (or an appliance/garage door/the electricity), but for the most part I’ve been successful in keeping everything in one piece. And I’ve enjoyed the farm life in the meantime.

Even though I’ve owned and cared for horses off and on throughout my life, I get lessons in horse care every time I farm sit. Once it was “Bowed Tendon Rehab 101” and “Don’t Have a Heart Attack When You See the Older Belgian Cross Stretched Out Flat in the Moonlight.” Then there was the “It’s Never Good to Hear Unattended Hoofbeats in the Aisle” lesson. All provided very practical take-homes. My most recent stay at the farm also taught me something very useful: While manure happens, sometimes it presents surprises.

Sacrifice area

Seeing these little reddish bullets in the gelding's manure made me reconsider breakfast.

My friends are solid, legit horse people who take incredible care of their animals. They know a good horse when they see one, all of their mounts have good minds and are troopers over all types of terrain, and their barn, paddocks, and pastures are designed to be a chore-efficient and safe. They work closely with their veterinarian to make sure each of their equine charges is in tip-top shape, covering all their preventive care bases.

Recently, they acquired a delightful little Quarter Horse gelding. He is extremely friendly and was hanging out at the gate with me after I put the horses to the drylot one morning. He pooped by the gate--not an unusual circumstance. But to my disgust there were curious little reddish bullets ... bots! …  right there in his manure. I hadn't seen these little nasties in 3-D since the nightmarish jar of preserved ones on the 4-H Hippology Contest table 18 years ago. Seeing them again was enough to make me reconsider whether I’d have an appetite for breakfast … or anything again, for that matter. 

Since this was something I’d never seen, I asked Martin Nielsen, DVM, PhD, assistant professor in parasitology at the University of Kentucky’s Gluck Equine Research Center and a longtime source for The Horse on parasites, about how common this finding is. He shared the following points with me on bots:

  1.  “There is no link between bots and fecal egg counts. Simply because bots (the larvae) don’t lay eggs.” Bots technically aren’t worms (they are a life stage of botflies, which you might see buzzing around and laying tiny insect eggs on your horse's legs). This is something easily forgotten since bots are in the parasite category. So, while my friends run fecal egg count tests regularly on their horses, this wasn’t something that could be caught on such a test. Fecal egg count tests detect worms. 
  2. “There is no association between presence of bots in the feces and the size of (a horse’s) worm burden.”  
  3.  “During the spring, it is part of the normal life cycle to see bots in the feces.” He continued: “Bots are very common. All horses are exposed, and it is not unusual to see the bots in feces. We take notice of the bots, because they are large, but we don’t see the worms because many of them are too small for us to see. Seeing bots in the feces does not indicate a large burden. Bottom line is that the bots are gross to look at, but they are not really a problem.”

This discovery was a reminder to me to brush up on my bot knowledge. Here’s a good overview on bots from our archives that describes life cycle and the varying opinions on the amount of damage bots can cause; most parasitologists we consult have shared Dr. Nielsen’s view on this matter. He notes that in his opinion, "The top five parasites (in terms of how "bad" they are) are 1) Large roundworms (ascarids), 2) cyathostomins (small strongyles), 3) large strongyles (bloodworms), 4) tapeworms. Bots may make it to the fifth position, but other parasites like threadworms, pinworms, and the skin nematodes Habronema, Draschia, and Onchocerca may be considered before the bots."

Anyhow, I let the gelding’s owners know about my discovery. Incidentally, they ran their semiannual fecal egg count tests a few weeks later, assessing the herd’s need for deworming. Everyone looked good (which corroborates with Dr. Nielsen’s assertion about bots not showing up on such a test and their presence in manure not indicating a problem with worms in general). I’m also happy to report that I recovered from my bot squeamishness, although I’ll probably never eat anything that resembles gnocchi.

Your turn: Have you ever found bots in a manure pile? How do you approach parasite control (from flies to worms) on your farm?