ABSTRACTAn 8‐year‐old, spayed female Labrador Retriever, which had been treated with oestrogens for urinary incontinence, developed non‐pruritic, bilaterally‐symmetrical alopecia and skin hyperpigmentation, with enlargement of mammary glands and vulva. Skin biopsy changes were consistent with an endocrine alopecia, hypothyroidism and hyperadrenocorticism were excluded by hormonal tests. Oestrogen‐induced alopecia was suspected and hormonal treatment withdrawn. Two months later, hair regrowth was almost complete and genital changes were