Distribution of neoplasia in Danish cats: data from the Danish Veterinary Cancer Registry

ObjectivesThe Danish Veterinary Cancer Registry (DVCR) was founded at the University of Copenhagen (then the Royal Veterinary and Agricultural University) in 2005 and has collected data from feline neoplastic cases ever since. To date, only canine data have been published. The objective of the current publication was to describe the distribution of neoplasms in Danish cats based on data from the DVCR.MethodsFeline DVCR data (2005-2023) were extracted in December 2023. Study parameters were age, sex, breed, tumour type, tumour biological behaviour, anatomical location and method for obtaining the diagnosis. Standard morbidity ratios (SMRs) were calculated using breed data from the Danish Cat Registry as the denominator.ResultsA total of 767 neoplasms were registered. More neoplasms were malignant (561, 73.1%) than benign (175, 22.8%). More neoplasms were registered in female cats (423, 55.8%) than in male cats (335, 44.2%). The mean (±SD) cat age was 10.4 ± 3.8 years. Malignant epithelial tumours were the most common type (259, 33.8%), followed by malignant lymphoma (141, 18.4%), benign epithelial (120, 15.6%) and soft tissue sarcomas (79, 10.3%). The most common anatomical location was skin including adnexal tissue (213, 27.8%), followed by haemolymphatic tissue (152, 19.8%) and mammary tissue (151, 19.7%). Domestic/European shorthair cats had SMRs less than 1.0, while all purebred cats with more than 15 registrations had SMRs greater than 2.0. The relative risk for having a mammary tumour was 2.08 for intact vs spayed female cats.Conclusions and relevanceIt was shown that Danish cats mainly get malignant tumours, and that skin and epithelial tumours were the most common. Overall, the results from the DVCR fit well with data from other recent European publications and will be helpful for informing owners and veterinarians about the occurrence of feline cancer in Denmark and comparable countries.