vet needs urine sample off one of our cats.
cats haven't used litter trays since they were kittens many years ago and go to garden and are free to go in and out as they wish.
Have got litter tray from vet with special crystals to collect urine.
have had cat locked in conservatory for 2 hours with food and water and litter tray .
How long do I wait ???
Any tips pleeeeassse.... ?