I’ve recently become aware of mulesing, an appalling practice used on Merino sheep in Australia and NZ due to a specific fly problem. The problem is that most merino wool is from those countries.
Also, most fabric generically labeled ‘wool’ is mostly merino from mulesinged sheep.
Ethics conscious knitters, crocheters and weavers are aware, and merino yarns certified as mulesing-free are on the market now.
Knowing country of origin and wool type is another reliable way to avoid endorsing this practice, but again most manufactured clothing or even fabrics will not give the necessary information.