Analysis of large datasets of uroliths is necessary to illustrate the prevalence and risk factors of urolithiasis. Furthermore, it may help to improve treatment and prevention of urolithiasis. In this study, 7866 uroliths (44.5% feline and 55.5% canine) from veterinary practitioners in the Netherlands between 2014 and 2020 were analysed. Between 2014 and 2020 the distribution over the different types of uroliths remained similar over time. Female cats, obese cats, Domestic Shorthair cats, female dogs, and large breed dogs had an increased risk for struvite. Neutered cats, all cat breeds except Domestic Shorthair, neutered dogs, male dogs, intact male dogs, and small breed dogs had an increased risk for calcium oxalate urolithiasis. Cystine and urate were found predominantly in male dogs. Dalmatians were at highest risk for urate urolithiasis. The findings of this study in the Netherlands were similar to findings in previous studies from different countries. However, urate urolithiasis in the English Cocker Spaniel and cystine urolithiasis in the Yorkshire Terrier were new associations. Body condition score, information about recurrence of urolithiasis, medical history, and diet history should be included in submission sheets in the future to explore other possible associations.

Supplementary feeding can affect populations of birds. It reduces energy spent on foraging and reduces the risk of starvation, but it also increases the risk of disease transmission and predation. Supplementary feeding may reduce species richness if some species are better able to exploit supplementary food resources than others. Feeding may also artificially inflate the carrying capacity of the ecosystem, leading to bird nuisance in the form of droppings and noise. The aim of this study was to characterise and quantify the risk factors and consequences of feeding free‐living birds in public areas in the western part of the city of Amsterdam. In seven study areas, the following data were collected: bird population size and species composition, feeding events, and the type and amount of supplementary food offered. Estimations were made of the nutritional energy provided and the number of birds that could be supported by the food offered. Members of the public who fed the birds were invited to complete a questionnaire on various aspects of feeding. Results showed that supplementary feeding attracts juvenile gulls and feral pigeons, which could in the long‐term affect biodiversity. Bread was the main category of supplementary food being offered (estimated to be 67% of the total amount of food). The majority of respondents fed birds so as not to waste bread and meal leftovers. In six of the seven areas studied, an overabundance of nutritional energy was calculated. We conclude that the current type and extent of supplementary feeding in the city of Amsterdam is nutritionally unbalanced and affects species diversity at a local level. The overabundance is undesirable for reasons of both animal health, because it can lead to malnutrition, and public health, because surplus food attracts rats and may also have a negative effect on water quality.