Three dogs were investigated for chronic unilateral nasal discharge. In all cases CT imaging showed an intranasal mass causing turbinate lysis and no evidence of metastasis. Cytology in cases 1 (a 14-year-old neutered male crossbreed dog) and 2 (a five-year-old neutered male German Shepherd dog) demonstrated a pleomorphic cell population with variable intracellular pigment suspicious of melanocytic neoplasia. Histopathology with immunohistochemistry (Melan-A and vimentin, plus PNL-2 in one case) confirmed the diagnosis of melanoma in all dogs. All dogs were treated with megavoltage radiotherapy using linear accelerators. Cases 1 and 3 (a 9-year-old neutered female beagle dog) received a hypofractionated (4x8 Gy) protocol and case 2 received a definitive (12x4 Gy) protocol. Complete remission was demonstrated on repeat CT scan 5 months after diagnosis in case 1 and 7 months in case 2. Stable disease was documented on CT at four months for case 3, however, clinical signs in this dog remained controlled for 10 months in total. Case 1 died of unrelated causes 5 months after diagnosis, case 2 was euthanased due to the development of seizures 13 months after diagnosis, and case 3 was lost to follow-up 12 months after diagnosis. Melanoma should be considered as a rare differential diagnosis for primary nasal neoplasia in the dog and radiation therapy can be used as effective local therapy.

Background After a strong epidemiological link to diet was established in an outbreak of pancytopenia in cats in spring 2021 in the United Kingdom, 3 dry diets were recalled. Concentrations of the hemato‐ and myelotoxic mycotoxins T‐2, HT‐2 and diacetoxyscirpenol (DAS) greater than the European Commission guidance for dry cat foods were detected in the recalled diets. Objectives To describe clinical and clinicopathological findings in cats diagnosed with suspected diet induced pancytopenia. Animals Fifty cats presenting with pancytopenia after exposure to a recalled diet. Methods Multicenter retrospective case series study. Cats with known exposure to 1 of the recalled diets were included if presented with bi‐ or pancytopenia and underwent bone marrow examination. Results Case fatality rate was 78%. Bone marrow aspirates and biopsy examination results were available in 23 cats; 19 cats had a bone marrow aspirate, and 8 cats had a biopsy core, available for examination. Bone marrow hypo to aplasia—often affecting all cell lines—was the main feature in all 31 available core specimens. A disproportionately pronounced effect on myeloid and megakaryocytic cells was observed in 19 cats. Myelofibrosis or bone marrow necrosis was not a feature. Conclusion and Clinical Importance Mycotoxin induced pancytopenia should be considered as differential diagnosis in otherwise healthy cats presenting with bi‐ or pancytopenia and bone marrow hypo‐ to aplasia.

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