Nasal hyperkeratosis in Griffon breeds: Clinical, histopathological features and the prevalence in the Swedish population compared to a control group and other brachycephalic breeds.

BACKGROUND: In the Griffon breeds (GB) nasal hyperkeratosis is common and develops already in early adulthood. Breed-related features and prevalence have not previously been documented. HYPOTHESIS/OBJECTIVES: To describe clinical and histopathological features of nasal hyperkeratosis in GB and to document the prevalence. MATERIALS AND METHODS: Seven GB dogs with nasal hyperkeratosis were examined. Three histopathological samples were analysed. Owners of 107 GB and 493 control dogs completed a questionnaire distributed via social media. RESULTS: Typical features of nasal hyperkeratosis in GB included varying degrees of dry, firm, excessive proliferation of keratin, affecting the dorsal or dorsolateral aspect of the planum nasale. Histopathology was characterized by severe, lamellar orthokeratotic and focal parakeratotic hyperkeratosis and multiple small serum lakes. Thirty-four of 107 GB dogs (31.8%) and 65 of 493 (13.2%) control dogs had varying degree of nasal hyperkeratosis. No sex predisposition was noted. Median age of onset was 3 years for GB, similar to brachycephalic control dogs whereas non-brachycephalic control dogs had a significantly later age of onset (p = 0.0053). CONCLUSIONS AND CLINICAL IMPORTANCE: Idiopathic nasal hyperkeratosis is very common in GB dogs and other brachycephalic breeds with nearly one third being affected, often already a young age.

Clinical and histological characterization of multifocal, spontaneous, noninfectious alopecia in Norwegian puffin dogs (lundehunds).

BACKGROUND: A noninfectious, spontaneous, multifocal alopecia has been recognized in Norwegian puffin dogs. HYPOTHESIS/OBJECTIVES: This study aimed to report demographic information, history, clinical signs, histopathological features and follow-up information for alopecic Norwegian puffin dogs from Sweden. MATERIAL AND METHODS: A questionnaire was sent out to all members of the breed association. Dogs clinically diagnosed with alopecia and biopsied were allocated to Group A. Dogs reported with alopecia for which histopathology was not available were allocated to Group B. RESULTS: Group A included 14 dogs (11.7% of the breed population in Sweden). Information regarding 72 dogs (60% of the breed population) was collected via questionnaire, and alopecia without histopathology was reported in another five dogs (Group B). Gender distribution was equal. Median age of onset was 1.5 years (range 8 months to 7 years). Multifocal or serpiginous alopecia, follicular plugging, dry skin, slight scaling and pruritus were characteristic. Extensive, widespread alopecia was not seen, and lesions were recorded only in haired skin. A lymphoplasmacytic, mural, isthmus folliculitis/perifolliculitis with follicular and perifollicular mucin was observed. Inflammation did not involve the hair bulb; atrophy was sometimes present. The inflammation sometimes extended to sebaceous glands, resulting in atrophy and absence of glands. Follow-up ranged from 6 months to 12 years (mean 3.2 years). Spontaneous remission was rare. Estrus was associated with worsening of the disease or relapse. Oral prednisolone reduced pruritus but was not effective in resolving clinical lesions. All dogs treated with ciclosporin went into remission. CONCLUSIONS AND CLINICAL IMPORTANCE: This is the first report of mural, mucinotic, isthmus folliculitis alopecia in Norwegian puffin dogs.