Pattern alopecia in dogs: Dachshunds, Chihuahuas and Greyhounds
2-year-old female Dachshund with progressive symmetrical hair loss on the pinnae, behind the ears, ventral neck, ventral thorax and caudomedial thighs. The skin is not inflamed and the remaining hair is short and very fine. No pruritus. Scrapings are negative and T4/TSH are normal.
What is the most likely diagnosis?
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A. Hypothyroidism with T4 still within range
A young bitch without systemic signs and with normal T4 and TSH is not a candidate for hypothyroidism; the distribution is typical of a breed pattern.
B. Colour dilution alopecia
Colour dilution alopecia is limited to dilute-coloured areas and causes fractured shafts and folliculitis, not miniaturisation in ventral areas.
C. Pattern alopecia due to progressive follicular miniaturisation
Correct. The breed, age of onset, typical distribution and progressively shorter, finer hair without inflammation are characteristic. Biopsy shows miniaturised follicles and shafts. It is cosmetic; melatonin may help in some cases.
D. Alopecia X
Alopecia X affects plush-coated or Nordic breeds, with loss of primary hairs on the trunk and tail; it does not present as this ventral miniaturisation in a short-haired Dachshund.
lightbulb Key takeaway
Pattern alopecia occurs in short-coated breeds (Dachshund, Chihuahua, Boston Terrier, Whippet, Greyhound, Italian Greyhound) from about one year of age. Variants include pinnal alopecia of male Dachshunds and the 'bald thigh' of Greyhounds. The diagnosis is clinical, after ruling out endocrine disease and demodicosis.
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Updated: October 31, 2026 · Educational content for veterinary professionals. It does not replace current clinical guidelines or the judgement of the attending veterinarian.