The leaf of the olive tree has been touted for its many benefits. From ancient times it has been used medicinally and in food. The phenolic compounds it contains are what produce these benefits, mainly a certain one called oleuropein. This magnificent compound has fairly potent antimicrobial capabilities, including antibiotic and antifungal properties. Some people have used it to fight bacterial infection by making it into a salve or feeding it directly. What we usually recommend it for is to fight yeast infections (ie. FUNGUS).
We wrote an entire article on yeast and a condition called Yeast Candida a while ago, so I will just briefly touch on it here. You can read the article from this link: Yeast Candida in Our Pets. A common problem in pets nowadays is this condition, Yeast Candida. It presents as darkening of the skin, itching, chewing paws, a mould smell, black mouldy buildup in the ears, or any combination of these depending on the severity. It is generally caused by medications or situations that kill the healthy gut bacteria, such as antibiotics, vaccines, stress, etc. The yeast then takes over the body and starts coming our the ear, paws, and skin. It can be very difficult to put the body back in order again. Olive leaf is a proven antifungal , and when it is consumed it kills yeast in the body. It is always a good idea to pair it with a good probiotic to help encourage healthy flora in the intestines to repopulate and restore balance. One important thing to also consider when attempting to rid your pet (or yourself!) of Yeast Candida is to cut out as much starch and sugar as possible. Yeast love to feed on carbs so consuming them will only help the yeast grow. Doing any of these should help, but if there is a severe case of Yeast Candida then it could take several months for significant improvement.
Another feat that olive leaf accomplishes is boosting the immune system! Due to its antioxidant and anti-inflammatory capabilities, as well as its antimicrobial properties, it helps give the immune system a push and a helping hand. Antioxidants help protect your cells from cancer-causing free radicals, which makes olive leaf a great preventative medicine. I’ll admit, not many people do preventative medicine because as a society we are used to waiting until a problem arises and then fixing it. However, cancer is not easily fixed, and by consuming antioxidants you give your pet one more tool to fight with.
An interesting function of the oleuropein in olive leaf is that it can actually reduce fat build in the liver. In a study done in mice, those fed a high fat diet while also consuming oleuropein had much less fat buildup in their liver tissue . It has even been indicated as a potential substance to use in preventing and perhaps treating Alzheimer’s .
As you can see the olive plant is pretty amazing! With such a wide variety of benefits it I can’t help but feel upset that constituents like this are not being used regularly in modern medical practices.
 Evaluation of the antifungal activity of olive leaf aqueous extracts against Candida albicans PTCC-5027, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5490280/
 Effects of the Olive-Derived Polyphenol Oleuropein on Human Health, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4227229/
Olive Leaf Extract: Dosage, Benefits, Side Effects, and More, https://www.healthline.com/health/olive-leaf-extract