Occasionally, you may need to collect a urine sample from your horse to be analyzed by your vet. This is not difficult to do, but does require good timing on your part.
Typically, your vet will only need a few ounces of urine for testing, but you should ask them how much they need, particularly if they will be performing multiple tests.
A handy way to cleanly catch urine is to attach a disposable coffee cup to a broom handle and keep it right outside the stall. When your horse begins to urinate, slowly move this apparatus towards their urine stream until it is directly underneath. You can also use a bucket.
Try to catch the urine midstream, if possible. This is the most representative of what is being produced. Cover the cup of urine with a bag or plastic wrap, or pour it into a glass jar and cover with a lid. Collected urine should be refrigerated (and properly labeled) and delivered to your vet as soon as possible, certainly within 24 hours.
Tips for safety & Success
Whatever you use to catch the urine (broom and cup apparatus or bucket), introduce this equipment to your horse before you place it under them for collection.
Ensure that you have some time to wait for this occasion to arise. If you know your horse's feeding and drinking patterns well, set yourself up for success by timing your collection efforts appropriately.