Tumors of the urinary system in cats

Tumors of the urinary tract of cats are uncommon. Although a few surveys have been performed worldwide, inves- tigation of these tumors in Croatia is lacking. The purpose of this research was to document epidemiological and tumor data from cats with urinary tumors. The study included cats histologically diagnosed with urinary tumors at the Depart- ment of Veterinary Pathology from 2009 to 2022. The following data were analyzed: the breed, sex, and age of the cats, tumor location, tumor type, and biological behavior. Tumors affected the urinary system in 34 cats, corresponding to tumor prevalence of 1.06% (general population), and 3.26% (tumor-bearing cats). Non-purebred cats (73.53%) and fe- males (61.77%) were overrepresented. The average age of the affected animals was 9.42 years. The most frequent diag- noses were lymphoma (58.82%) and urothelial carcinoma (17.65%). The affected locations were the kidneys (73.53%) and urinary bladder (26.47%). Most tumors were malignant (97.06%). Where it could be determined, the cause of death was disseminated neoplastic disease with concurrent affection of the urinary system (75%), and primary urinary neo- plasia (15%), while in 10% urinary tumors were not associated with the cause of death. This study gives an insight into the urinary tumors that affect Croatian felines. The tumor prevalence and types diagnosed correspond to the literature data, showing that the Croatian population suffers from the same tumors as populations elsewhere. The affected cats were usually of old age, female, and non-purebred, and often had a disseminated neoplastic disease, and grave prognosis. The low prevalence indicates that these tumors are rare, but nevertheless important diseases of the urinary tract in cats.