TLDR A French bulldog had sparse hair due to a condition similar to that seen in Chinese crested dogs.
The document described a case of congenital alopecia in one of four female French bulldogs from a litter. The affected dog was otherwise clinically normal, with sparse hair distribution on the head, tip of the tail, and paws, similar to the Chinese crested dog. Histopathological examination of skin biopsies showed a reduction in the number of hair follicles, hypoplasia or absence of epidermal appendages, and pronounced follicular hyperkeratosis. No abnormalities in collagen and elastic fibers were detected.
Low-dose oral isotretinoin improved hair loss and facial bumps in patients with a specific type of hair loss.
November 2019 in “Harper's Textbook of Pediatric Dermatology” Understanding normal hair growth and loss in children is key to diagnosing and treating hair disorders.
7 citations
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August 2018 in “The American Journal of Dermatopathology” Researchers found a new early sign of Frontal Fibrosing Alopecia that could help avoid misdiagnosis.
4 citations
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August 2016 in “JEADV. Journal of the European Academy of Dermatology and Venereology/Journal of the European Academy of Dermatology and Venereology” Using cetirizine on the skin and taking vitamin D can help increase hair growth in children with hair loss from ectodermal dysplasia.
189 citations
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May 1991 in “Medical Entomology and Zoology” 
5 citations
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October 1988 in “Clinics in Dermatology” Minoxidil promotes hair growth but exact mechanism is unknown.
