IL-31 receptor antagonist biologics — the monoclonal antibodies (lokivetmab/Zoetis) and JAK inhibitors (oclacitinib/Zoetis, upadacitinib/Elanco) targeting the IL-31 itch pathway with rapid onset (4 hours for oclacitinib, 24 hours for lokivetmab) and sustained control without corticosteroid side effects — represent the fastest-growing therapeutic class in the canine atopic dermatitis...