Feline cystadenomatosis affecting the ears and skin of 57 cats (2011-2019).

OBJECTIVES: This study aimed to understand epidemiological factors associated with feline cystadenomatosis, including signalment and papillomavirus PCR status. Cystadenomatosis is an uncommon condition primarily involving the ceruminous and apocrine skin and ear glands. METHODS: This was a retrospective case series. Clinical records from 2011 to 2019 from a tertiary referral hospital in Boston, MA, USA were screened for cases, and case data were re-evaluated and analyzed. The total patient pool contained 65,385 individual cats, of which 797 were referred to the dermatology service. Medical records and biopsy specimens were reviewed; the information collected included signalment, clinical signs, physical examination and diagnostic tests, comorbidities and histopathologic findings. PCR was performed on biopsy specimens to test for papillomavirus DNA. RESULTS: The cystadenomatosis population consisted of 57 cases (7.1% of total cases referred to the dermatology service) with 105 affected ears. Twenty-seven cases (48 ears) were confirmed via histopathology; four cats (7%) exhibited clinically cystic lesions on the periocular, periorbital and perianal regions; only one cat did not have pinnal lesions. Domestic shorthair cats were most often affected. Relative risk for cystadenomatosis was 2.24 times higher in male cats. In 48 cats (84.2%), ears were bilaterally affected. Seven cats (12.3%) had malignant neoplasia, which included: inflamed adenocarcinoma (n = 5); mast cell tumor (n = 1); or squamous cell carcinoma (n = 1). PCR testing on biopsy specimens from 24 cats revealed feline papillomavirus type 2 DNA in only four cats. CONCLUSIONS AND RELEVANCE: Cystadenomatosis was more prevalent in senior non-purebred cats, over-represented in male cats and did not appear to be associated with papillomavirus, feline infectious peritonitis, feline immunodeficiency virus/feline leukemia virus status or other identifiable illnesses. Further studies are needed to investigate the causes of cystadenomatosis.

Shortened immunotherapy dose-escalation saves time, but is it safe? A case-control study comparing the rates of adverse reactions between conventional and fast-escalation subcutaneous immunotherapy protocols during the induction phase.

BACKGROUND: Allergen immunotherapy (AIT) is the only intervention believed to change the course of atopic diseases. As dogs appear to have fewer severe adverse events (AEs) compared to people receiving AIT, a prolonged dose-escalation induction phase might not be needed. OBJECTIVES: To report the incidence and characteristics of AEs induced by a fast-escalation subcutaneous immunotherapy (f-SCIT) protocol compared to a conventional (c-SCIT) regimen. ANIMALS: One hundred dogs treated with either f- SCIT (Centre 1, 50 dogs) or c-SCIT (Centre 2, 50 dogs). METHODS AND MATERIALS: A case-control study retrospectively evaluating AEs during the induction of AIT. We determined the incidence and type of AEs in each SCIT group; we also assessed factors such as self-limitation and the need for AE-associated protocol changes. RESULTS: Twelve of 100 dogs (12%) developed a SCIT-attributable AE during the induction phase, with one dog having a local and 11 having systemic reactions (nine Grade I, two Grade II, none of grades III or IV). Dogs treated with the f-SCIT had a significantly higher rate of AEs (11 of 50; 22%) compared to those receiving the c-SCIT (one of 50; 2%). Most of the AEs (10 of 11; 91%) in the f-SCIT group were mild and self-limiting. CONCLUSIONS AND CLINICAL IMPORTANCE: The induction phase of f-SCIT is simpler, and the maintenance phase is reached faster than that of the c-SCIT. Despite its higher rate of AEs than with the c-SCIT regimen, the majority of f-SCIT-associated AEs were mild and self-limiting. Whether or not this f-SCIT protocol leads to a faster time-to-efficacy needs to be determined.

Scaling dermatosis in three dogs associated with abnormal sebaceous gland differentiation.

BACKGROUND: Abnormal sebaceous gland differentiation, so-called 'sebaceous gland dysplasia', is a rare condition described in the dog and the cat. Although little is known about this condition, it is thought that a genetic defect causes abnormal sebaceous gland development. Clinically, this condition occurs in young cats and dogs and is characterized by variable degrees of adherent scale, hair casts, poor coat quality and hypotrichosis. HYPOTHESIS/OBJECTIVE: Here, we describe the clinical presentation and treatment of three adult dogs with abnormal sebaceous gland differentiation. ANIMALS: Three adult dogs presented with a keratinization defect characterized by progressive scaling, hair casts, dull, dry, brittle hair coat and hypotrichosis beginning in puppyhood to early adulthood. METHODS: Multiple 6 mm punch skin biopsy samples were obtained from each dog. Treatments included various topical keratomodulatory agents, oral essential fatty acids and oral vitamin A. RESULTS: Histologically, all sebaceous glands were small and composed of a mixture of irregularly clustered basal reserve cells and mature sebocytes. With therapy, two of the dogs showed moderate to marked clinical improvement in scaling, hair casts and hair coat quality. CONCLUSIONS AND CLINICAL IMPORTANCE: Although rare, 'sebaceous gland dysplasia' should be considered in cases where a primary keratinization defect is suspected. Given that abnormal sebaceous differentiation is a structural defect of the skin, treatment must be maintained and is aimed at ameliorating the clinical signs rather than curing the disease.