Here is my list of the most powerful group of antimicrobial essential oils available to us for use in birds, based on current studies that I have seen as well as my own experience.
OREGANO: Oregano is all by itself on the highest level of antimicrobial action. It has the broadest spectrum of all the essential oils which means that it kills the widest range of microbes. It is fairly caustic to skin, and may raise liver enzymes if used over extended periods. It is also a strong digestive stimulant, and stimulates both immunity and energy levels. However, it is perfectly safe for short term, intense use. This is the oil to reach for when the plague is closing in:)
THYME, CINNAMON, CLOVE, TEA TREE, MOUNTAIN SAVORY: these are all really powerful antimicrobials and you will see them as the big players in antimicrobial blends, usually mixed with oils from levels three and four below. The more of these oils in a blend, the better it will work. All of these oils are fairly irritating in the same sense that oregano is, they will irritate skin and mucus membranes, they are strong stimulants and should not be used in significant concentrations long term on birds, but work wonderfully in short. intense bursts.
NOTE: My all time favorite essential oil is THYME THUJANOL from Original Swiss Aromatics. Thujanol is the oil I reach for when I need to use a topical antimicrobial with birds because it is the only truly powerful, broad spectrum EO that is gentle in action. For example, I have used thyme thujanol neat (undiluted) on a finch’s face; I have also used thujanol at 5% dilution in sesame oil for three weeks topically on delicate abdominal tissue to help correct intestinal infections.
MYRRH, PEPPERMINT, ROSEMARY, EUCALYPTUS, LEMON, BAY LAUREL, RAVENSARA, PALMAROSA, HYSSOP, LEMONGRASS: these oils all perform different functions extremely well. For example, eucalyptus and peppermint are exceptional for respiratory infections, myrrh is amazing for oral infections, bay laurel, palmarosa and ravensara are especially good with viral infections etc. Therefore these oils will often be added to blends with the stronger broad spectrum oils from levels one and two. If you were dealing with a really serious virus like Pacheco’s you might want to choose oregano plus thyme plus cinnamon and then fill in with ravensara, palmarosa, bay laurel and rosemary, that type of thing.
LAVENDER, JUNIPER, MARJORAM: I use these oils (and there are lots more of these) when infection is not my primary concern, but it is on the table. For example, if there is a skin wound that is not yet infected, but I need to prevent infection, then I might choose lavender because it is so good at healing wounds and it will stave off potential infection nicely. In this example, you wouldn’t use oils from levels one or two because it would be overkill and they are not gentle enough for the skin.
Disclaimer: These statements have not been evaluated by the Food and Drug Administration, or by any veterinarian. All information, including any product or technique mentioned, is for educational purposes only. None of the information is intended to diagnose or treat any disease.