It looks like a bit of embroidery. I'm baffled.
My immediate thought is a toothbrush but then I saw your clue...surely not a canine toothbrush? I wouldn't like to try my chances with Louis :-) I can't think of anything else it could be and have probably made a complete fool of myself with that guess! Thank you very much for my gold star last week John :-)
I'm wondering if it could possibly be a portion Penny's reflective collar?
Penny's walking lead.
Thank you for visiting. Hope you enjoyed the pictures. Any comment, or correction to any information or identification I get wrong, is most welcome. John