A number of other terms for this condition include adult-onset growth hormone deficiency, growth hormone-responsive alopecia, castration-responsive alopecia and adrenal hyperplasia-like syndrome. No significant changes in sex hormone concentrations have been noted in these dogs. Use of estrogen-receptor antagonists have been shown to be ineffective in female dogs, suggesting reproductive hormones may not be involved in the etiology of this condition. However, some dogs have shown elevation in progesterone levels when injected with synthetic ACTH, suggesting a role of pituitary disease in this phenomenon or underlying borderline hyperadrenocorticism.
Alopecia X affects dogs of both sexes regardless of neuter status. The hair loss can first occur at any age and affected dogs present with gradual loss of hair over the trunk and caudal thighs, sparing the head and front limbs. Sometimes the guard hairs are lost first leaving a soft 'puppy' coat. The skin may become intensely hyperpigmented. There are no systemic signs associated with this condition.
Histological examination usually reveals hyperkeratosis, follicular keratosis, excessive tricholemmal keratinization (flame follicles), thin epidermis, few small anagen bulbs, epidermal pigmentation and melanin aggregates within follicular keratin. Dogs with alopecia X also have the lowest percentage of anagen follicles and the highest percentage of telogen follicles.
Apart from alopecia, most dogs are generally unaffected by the condition.
- ↑ Dr R Hilton
- ↑ Mausberg EM et al (2007) Evaluation of the CTSL2 gene as a candidate gene for alopecia X in Pomeranians and Keeshonden. Anim Biotechnol 18(4):291-296
- ↑ Frank LA et al (2004) Adrenal steroid hormone concentrations in dogs with hair cycle arrest (Alopecia X) before and during treatment with melatonin and mitotane. Vet Dermatol 15(5):278-284
- ↑ Frank LA (2007) Oestrogen receptor antagonist and hair regrowth in dogs with hair cycle arrest (alopecia X). Vet Dermatol 18(1):63-66
- ↑ Leone F et al (2005) The use of trilostane for the treatment of alopecia X in Alaskan malamutes. J Am Anim Hosp Assoc 41(5):336-342
- ↑ Mausberg EM et al (2008) Exclusion of patched homolog 2 (PTCH2) as a candidate gene for alopecia X in Pomeranians and Keeshonden. Vet Rec 163(4):121-123
- ↑ Mausberg EM et al (2007) Inherited alopecia X in Pomeranians. Dtsch Tierarztl Wochenschr 114(4):129-134
- ↑ Lee YM et al (2005) A case of adrenal gland dependent hyperadrenocorticism with mitotane therapy in a Yorkshire terrier dog. J Vet Sci 6(4):363-366
- ↑ Campora L et al (2011) Mycobacterium avium subspecies hominissuis disseminated infection in a Basset Hound dog. J Vet Diagn Invest 23(5):1083-1087
- ↑ Müntener T et al (2012) Canine noninflammatory alopecia: a comprehensive evaluation of common and distinguishing histological characteristics. Vet Dermatol 23(3):206
- ↑ Cerundolo R et al (2004) Treatment of canine Alopecia X with trilostane. Vet Dermatol 15(5):285-293
- ↑ Frank LA et al (2006) Oestrogen receptor evaluation in Pomeranian dogs with hair cycle arrest (alopecia X) on melatonin supplementation. Vet Dermatol 17(4):252-258