Two cases of feline paraneoplastic alopecia associated with a neuroendocrine pancreatic neoplasia and a hepatosplenic plasma cell tumour.

BACKGROUND: Feline paraneoplastic alopecia (FPA) is a rare condition listed among the cutaneous paraneoplastic syndromes, which occurs in association with pancreatic carcinoma, cholangiocarcinoma, hepatocellular carcinoma and metastatic intestinal carcinoma. OBJECTIVES: To describe the clinicopathological findings of paraneoplastic alopecia in two cats each with an uncommon tumour not previously reported in association with FPA. ANIMALS: Paraneoplastic alopecia was associated with neuroendocrine pancreatic neoplasia in a Persian cat and with a hepatosplenic plasma cell tumour in a domestic short hair cat. RESULTS: FPA was suspected based on age, rapid onset of clinical signs, ventral distribution of alopecia, shiny appearance of the skin and telogenization/miniaturization of the follicles on histopathology. The nature of the tumours was determined through cytology, postmortem, histopathological and immunohistochemical examination, and capillary immunoelectrophoresis. A causative association between the skin lesions and the tumour was suggested by clinical and histopathological features shared with previously published cases. CONCLUSIONS AND CLINICAL IMPORTANCE: Pancreatic neuroendocrine and plasma cell tumour should be considered as differential diagnoses when evaluating FPA.

Clinical outcome and cyclo-oxygenase-2 expression in five dogs with solar dermatitis/actinic keratosis treated with firocoxib.

BACKGROUND: The conversion of arachidonic acid into prostaglandin is catalysed by the cyclo-oxygenases (COX-1/COX-2). Several studies indicate that COX-2 is overexpressed in actinic keratosis in humans and dogs. Firocoxib is a COX-2-selective inhibitor that blocks the biochemical activity of COX-2. HYPOTHESIS/OBJECTIVES: To evaluate the efficacy of firocoxib (5 mg/kg orally once daily) for the treatment of dogs with solar dermatitis/actinic keratosis. METHODS: Firocoxib 5 mg/kg was given orally once daily for 180 days to five dogs with clinical signs and histopathological lesions consistent with solar dermatitis/actinic keratosis. On days 0, 50 and 180, the severity of erythema, skin shine, induration and the number of comedones were evaluated by a clinical scoring system. On the same days, samples were collected for histopathology from 'target lesions' and COX-2 expression was evaluated by immunohistochemistry. RESULTS: The clinical follow-up showed that four of five dogs improved with the treatment; improvement in terms of histological findings was correlated with the regularization of the epidermal proliferation rather than the recovery of dermal changes. CONCLUSIONS AND CLINICAL IMPORTANCE: A role for COX-2 might thus be hypothesized in the pathogenesis of canine solar dermatitis.

Nodular lesions due to infestation by Dirofilaria repens in dogs from Italy.

BACKGROUND: Canine subcutaneous dirofilariosis caused by Dirofilaria repens is an important cause of human dirofilariosis in the Old World. OBJECTIVES: To describe the clinical and pathological features of infestation by D. repens in dogs with cutaneous nodules and to discuss key diagnostic procedures. ANIMALS: Sixteen privately owned dogs of different breeds, ages and genders with subcutaneous nodules were positive for D. repens on at least one diagnostic test. METHODS: Diagnostic tests included cytological examination of fine-needle aspiration biopsies, detection of circulating larvae by Knott's test, morphological and molecular identification of adult parasites and microfilariae, and histopathological examination of excised nodules. RESULTS: Twelve animals were positive for D. repens microfilariae, using cytology and at least one other diagnostic test. Four of twelve dogs screened by Knott's test had circulating D. repens microfilariae, and three of them were co-infected with Dirofilaria immitis. In eight dogs, adult nematodes were morphologically identified as D. repens. Nodular panniculitis was observed in all cases, with nodules containing either one or several cross-sections of nematodes and microfilariae. The nematodes extracted were identified as D. repens by an RT-PCR on the second internal transcribed spacer (ITS-2). CONCLUSIONS AND CLINICAL IMPORTANCE: Adults and larvae of D. repens can induce skin nodules in dogs, and these lesions should be carefully evaluated in endemic areas. Clinicians should be aware that correct tissue sampling (including the storage of part of a sample in ethanol instead of formalin) is pivotal to achievement of a specific diagnosis. Cytology of fine-needle tissue aspirates was shown to be useful.