You do not usually need to catch your birds up to diagnose a wet vent. You can see the messy feathers on the vent area by looking up at your bird while s/he is on the perch.  In a cage situation, you can also tell by examining the droppings in the bottom of the cage.  In fact, you should make it a regular part of your routine to examine the droppings whenever you change the paper. A loose watery dropping, or green feces is an indication of a problem.  Be aware that the droppings of different species can be very different so it is important to learn through observation what is normal for the species you keep.

If your bird is showing signs of a wet vent with no other symptoms, (i.e. fluffed feathers, listless stance, dull eyes) the first thing to do is add a source of heat by clipping a light (preferably black or red) to the side of a cage near a perch.  This allows your bird to get extra heat and so direct more of his body resources to healing. In cooler conditions, you may want to drape a towel over all or part of the cage to keep in the heat. You should also replace his regular water with an electrolyte solution.  I use Energize.  Because it comes in a powdered form, it has a longer shelf life.  I keep it in my avian first aid kit and mix up just what I need.

Once these basic steps have been taken, it is important to think about what caused the problem to begin with.  Have the birds been under stress? Molting, moving, drafts, new stimulus in the environment can all cause stress.  If so, as much as possible, remove or reduce the cause of stress. Next consider diet.  Have you added something new to the diet?  Adding new things is not bad.  In fact, many times we change the diet to more completely meet our birds dietary needs.  It is important, however, to add new foods slowly.  Start with small amounts and increase as you find your bird tolerating it well.  It takes time for our birds to develop the enzymes needed to digest new foods.

If you are unable to discern a stress or diet cause for the problem, you need to consider a disease process as the cause. Usually, but not always, a disease process will cause other symptoms than just a wet vent.  A culture needs to be done to determine the specific pathogen causing the problem and the medication that will best treat it.  While some people do there own cultures, most find it easier to have their veterinarian take and grow the culture.  It can take 24-48 hours to grow the culture and another 24-48 hours to run a sensitivity panel to chose the most effective medication.  With a finches fast metabolism, this 3-4 day delay is often fatal. Therefore, it is often prudent to begin treatment with a broad spectrum antibiotic like amtyl combined with an antiprotazoal like Ronivet immediately. These two products can safely be used at the same time.  Together, they will hit most common gastro intestinal organisms.  It is important to follow up with a probiotic after any antibiotic treatment.  this helps re establish the normal gut flora that is so critical for digestion and immunity functions.