No it doesn't affect shows more, it actually affects workers more as they are head down hunting and moving at speed.
Foxtails don't just enter the ear, they are hard sharp and pointed and have barbs so "travel" when the ear is shaken or scratched. It also gives them the ability to move through the body.
Jarvis, my old boy, has had one in a tear duct, one at the back of his eye and one that entered the bottom of the paw and luckily chose to come out the top of his paw rather than travel up his leg.
It's also common for them to be inhaled and end up in lungs - usually this manifests as an abscess on the left side of the body on the rib cage as it hopefully makes it's way out.
Jago had 9 in his paws, one in his eye and one in his ear after a day at daycare. I wasn't impressed......