Note for Pet Owners:

This information is provided by Provet for educational purposes only.

You should seek the advice of your veterinarian if your pet is ill as only he or she can correctly advise on the diagnosis and recommend the treatment that is most appropriate for your pet.

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Alopecia means hair loss. It can be localised to one area of the body, or generalised. It can occur unilaterally or it can be bilaterally symmetrical. The distribution of the hair loss is very helpful iin determining the likely cause.  

There are three main types of alopecia

  • Congenital / hereditary -
  • Acquired - develops during the life of the animal
  • Secondary to another disease process -  skin infections (eg ringworm), self-inflicted injury (eg allergy, parasites)

Congenital alopecia is a genetically inherited defect of hair follicles resulting in lack of hair (baldness)

Breed Occurrence

The  following breeds are bald at birth or develop hair loss within 2-4 weeks of birth as a breed characteristic :  American hairless terrier (autosomal recessive inheritance), Chinese crested dog,  Inca hairless dog, Mexican hairless dog (autosomal dominant inheritance), Peruvian Inca Orchid. The Sphinx cat.

The following breeds have been reported to develop the disease of congenital hypotrichosis and they are born with symetrical hair loss, or develop it soon after birth: the American Cocker Spaniel, Basset Hound, Beagle, Belgian Shepherd, Bichon Frise, French Bulldog, Labrador Retriever, Lhasa Apso, Rottweiler, Toy and Miniature Poodles,  Whippet, Yorkshire Terrier. There may be a sex-linked inheritance as males are usually affected.

The following breeds of cat have been reported to develop congenital hypotrichosis : the Birman (autosomal recessive inheritance - affected cats have no thymus on postmortem), Burmese (affected  cats have no claws, tongue papillae or whiskers) , Devon Rex and Siamese (autosomal recessive inheritance). 

The alopecia is bilateral and can be localised to involve certain regions:, temporal region, pinnae of the ear, undersurface of the body (ventrum), along the back (caudally), or it can involve the whole body. Later skin thickening and pigmentation may occur , and seborrhea is seen.

Sometimes affected animals have other abnormalities eg dogs may have abnormal dentition

Congenital hypotrichosis is confirmed from the presenting history and signs, and by histopathological examination of skin biopsy samples which demonstrate low numbers or an absence of hair follicles, sebaceous glands, sweat glands and arrector pili muscles.

There is no satisfactory treatment for this condition. Because it is an inherited defect affected animals should not be used for breeding, except in those breeds which are naturally bald.

Hair loss is not a serious disorder and affected dogs can be expected to live an otherwise normal life. However, they need protection from extreme cold weather. Mexican hairless dogs have a shorter life-expectancy than other similar (hairy) breeds

Long term problems
Chronic skin disease - eg seborrhoea


Updated January 2016