Page 1060 - Problem-Based Feline Medicine

50. The cat with alopecia

Ruadhri Michael Seosaimh Breathnach and Mike

Shipstone

KEY SIGNS
● Partial or complete loss of hair.

MECHANISM?
● Alopecia is the loss or absence of hairs from areas of the body that would normally possess
hairs.
● The most common mechanism is the excessive loss from over-grooming because of pruritus.
The characteristic feature of this mechanism is the presence of damaged/fractured ends to the
remaining hair shafts in the area of alopecia.
WHERE?
● Skin.

WHAT?
● Numerous pruritic conditions, most commonly allergic in origin, lead to alopecia from self-
trauma. Occasionally self-trauma can also arise for psychogenic reasons. Non-pruritic causes
may be congenital or hormonal in etiology, with hyperthyroidism and diabetes mellitus most
common. Folliculitis is seen with microbial or ectoparasitic infections, leading to non-pruritic
loss of hair.

QUICK REFERENCE SUMMARY
Diseases causing alopecia
PRURITIC CAUSES OF ALOPECIA
INFLAMMATORY

● Allergic (p 1030)
If fractured or cropped hairs are present in the affected areas, pruritus is the most likely cause. See
Chapter 48 (The Cat With Miliary Dermatitis or Pruritus).

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