A cortisol‐secreting adrenocortical tumour (ACT) is the cause of naturally occurring canine hypercortisolism in approximately 15% to 20% of cases. The differentiation between an adrenocortical adenoma and carcinoma is usually based on histopathology. However, histopathological parameters have never been linked to the dogs' survival. Moreover, in human medicine the inter‐observer variability of some histopathological parameters that are used for ACTs is high. The objective of this study was to establish a reliable and easy‐to‐use histopathological scoring system for cortisol‐secreting ACTs that can assess the prognosis of dogs after adrenalectomy. Cortisol‐secreting ACTs of 50 dogs, collected between 2002 and 2015, were included in this study. Twenty histopathological features were assessed by one veterinary pathologist and one resident in veterinary pathology. In addition, the Ki67 proliferation index was assessed by two observers. Only parameters with intra‐ and inter‐observer agreement scores (intra‐class correlation or Cohen's kappa coefficient) of ≥0.40 were included in survival analyses. Use of multivariate forward stepwise regression analysis with associated hazard ratios led us to a scoring system which we call the Utrecht score: the Ki67 proliferation index, +4 if more than 33% of the tumour cells have clear/vacuolated cytoplasm and + 3 if necrosis is present. Using cut‐off values of 6 and 11, we could distinguish three groups that had significantly shorter survival times with increasing Utrecht scores. We conclude that the Utrecht score can be used to assess the prognosis of dogs with cortisol‐secreting ACTs after adrenalectomy, which can help to select high‐risk dogs that might benefit from adjuvant treatment or additional monitoring.

A 6-year-old Rhodesian Ridgeback was presented with a 1.5 year history of right forelimb lameness. Clinical, radiological and computed tomographic findings suggested the presence of fragmented medial coronoid process. A subtotal coronoidectomy was performed and, due to the atypical appearance of the medial coronoid process on imaging and at surgery, histopathology of the fragments was performed which revealed chondroblastic OS. Ten months after surgery, the dog was re-presented with the same clinical signs and the radiographic changes were suggestive of a recurrence of the OS. Palliative therapy was instigated at the owner’s request. Thirty months after surgery of the neoplasm, the dog was presented with dyspnea. Thoracic radiographs showed lesions consistent with lung metastases. Euthanasia was requested by the owner, who declined post-mortem examination.

Encephalitozoon cuniculi is known to infect human beings, dogs, mink, cats, rodents, foxes, goats, horses, non-human primates, rats, ticks and the main host the rabbit (Oryctolagus cuniculus). Reports of E cuniculi in domestic cats (Felis catus) with histopathological changes are rare. This report describes an E cuniculi infection in the brain and kidneys of a six-week-old kitten. Postmortem examination was performed and microscopical examination of the brain and kidney revealed nodular infiltrates associated with Gram-positive microsporidian spores consistent with E cuniculi. PCR and immunohistochemistry confirm the findings. While E cuniculi infection in domestic cats is rare, this case demonstrates that it should be taken into consideration as a differential diagnosis for kittens with poor weight gain. Given the serious course of the disease and the risk of transmission to other littermates or other mammals including human beings, it is important to rule out an E cuniculi infection.