Hi Sreyasi, there are specific cages designed to capture excrement from lab animals.

https://www.harvardapparatus.com/metabolic-cage-for-mice-rats.html

http://www.lenderking.com/metamouse.html

If these are too costly then you can use a desiccator like this to keep a mouse confined and then wait.

https://www.fishersci.com/shop/products/nalgene-polypropylene-desiccator-stopcock/086425

We used to use female mice and glue shut the urethra with Superglue. At the time it was allowed wrt animal use protocol as long as the experiment was short and terminal so as to avoid discomfort. We would then remove the urine from the bladder using a tuberculin/26 ga syringe. Bladder urine volumes varied greatly but pre-dosing with water by oral gavage might help.

Thank you Steingrimur for your response. we generally use metabolic cages for overnight urine collection

but is that ok for enzymatic analysis?

Thank you Thomas!!

we work with male mice but will definitely try to collect from bladder using syringe.