Bots show some true animal cunning


In the latest episode of “The Parasite Journey of the Horse”, equine parasitologist Martin Nielsen checks out bots.

Bots are not worms, but they are parasites. There are several species of these insects, but the equine scene is dominated by gasterophilus intestinalis. “Most of the time when you see bots they’re from one single species. There are a few others that are extremely rare.”

The eggs of gasterophilus intestinalis are most likely found on the horse's legs, shoulders, and possibly the mane. The eggs of gasterophilus nasalis will be seen around the mouth.
The eggs of gasterophilus intestinalis are most likely found on the horse’s legs, shoulders, and possibly the mane. ©

Being insects, their lifecycle is different from the previous parasites. Bots are seen flying around mostly in late summer. Many horses don’t like them, but they don’t sting or bite and they never land on the horse. “The female flies are laying their eggs while they’re flying in the air, and they glue these eggs onto the coat of the horse,” Nielsen says.

Horses get infected while grooming each other, and the eggs hatch when they are breathed upon. Once the larvae get inside the mouth of the horse, they stay there for a while. The first migrate through the tongue.

“They burrow into the tissue to the flesh of the tongue and dig little tunnels,” Nielsen says.

When they make it to the base of the tongue at the back of the mouth, they come up and spend some time around the cheek molars, where they grab food as it passes by. They can sometimes leave a little crater in the bone by the teeth. After three weeks or so, they move on to their final destination.

Watch the video to find out more!

• We recommend watching the series in order:
Episode 1: Foal parasites
Episode 2: Ascarids, or roundworms
Episode 3: Small strongyles (cyathostomins)
Episode 4: Bloodworms
Episode 5: Tapeworms
Episode 6: Bots
Episode 7: Pinworms

See also: the inside secrets of “Creepy Crawlies”.

» For more from Dr Nielsen, check out his short video series on parasite control, starting here.

Martin K Nielsen

Dr Martin Nielsen is a professor in equine parasitology at the Maxwell H. Gluck Equine Research Center at the University of Kentucky. » Read Martin's profile

Leave a Reply

Your email address will not be published. Required fields are marked *