Clothes worn by pet yukkuri. Usually in the form of a round stocking that covers their bottom half.
Yukkuris, even those born and lived in streets and wild are very fond of pet clothes and often end up being happy when dressed in one.
Koyukkuris in particular are extremely fond of clothes. However, since their braids aren't as dexterous as an adult's, it's impossible for them to wear or remove clothes without assistance. And since koyukkuris lack cognitive thinking and bowel restraint, they often pee or shit inside their clothes and only realize the consequences afterwards. Smart and trained koyukkuri will usually ask their owners or parents to remove the clothes before using a bathroom. Otherwise diapers can be used as a last resort.
As for adult pets, whether they can or cannot remove their clothes by themselves varies between each story. Though adults doesn't seem to be as interested in clothes as koyukkuris and it's not uncommon to see a family of pets consisting of clothed children and unclothed parents. Parents can usually remove the clothes of their children if they need to defecate.
Pet clothes specifically refers to clothes worn by a normal yukkuri. Clothes worn by bodied yukkuri doesn't count.