Bob & Tom

In pets combination products containing multiple ingredients are more often prescribed than individual herbs. However, having an understanding of the individual herbs contained in the product can help the owner understand why the herb was included in the product. In people, St Johns Wort is often used to help control mild depression. In pets the herb is used as part of anti-anxiety formulas.

The active components in St John’s wort are found in the buds, flowers, and newest leaves. Extracts are usually standardized to the substance hypericin, which has led to the widespread misconception that hypericin is the active ingredient. However, there is no evidence that hypericin itself is an antidepressant. Recent attention has focused on another ingredient of ST John’s wort named hyperforin as the potential active ingredient.

It appears that standard ST. John’s wort extract contains about 1 to 6% hyperforin.

Early research suggested that St. John’s wort works like the oldest class of antidepressants, the MAO inhibitors. However, later research essentially discredited this idea. More recent research suggests that ST. John’sWort may raise levels of serotonin, norepinephrine, and dopamine. This probably increases neurotransmitters to maintain normal mood and emotional stability (the herb may also cause binding of GABA and act as a serotonin reuptake inhibitor.) Studies have used the standardized extract containing 0.14% hypericin.

Evidence from animal and human studies suggests that hyperforin is the ingredient in St John’s wort that raises these neurotransmitters. However, there may be other active ingredients in ST . John’s wort also at work.

The herb has been recommended for depression, separation anxiety, and certain forms of aggression in pets.

In people, ST . John’s wort is one of the best-documented herbal treatments, with a scientific record approaching that of many prescription drugs. It is a prescription antidepressant in Germany, covered by the national health-care system, and is prescribed more frequently for depression than any synthetic drug.

Saint John's wort is also useful for its antiviral and antibacterial properties. It also has tonic effects on nerves.

Interest in Saint John's wort is ongoing regarding antiviral activity and the potential to treat diseases including both human and feline AIDS infections. While definitive proof is lacking, it may be worthwhile to try Saint John's wort in pets with severe viral infections (canine distemper, feline leukemia and immunodeficiency infections.)

Applied locally, this herb is useful to heal wounds.

In people, the current recommendation is 300 mg three times daily of the 0.3% hypericin standardized solution as a treatment for depression. A few new products on the market are standardized to hyperforin content (usually 3 to 5%) instead of hypericin. These are taken at the same dosage.

In dogs, a dose of 250-300 mg twice daily for large dogs has been recommended and proven useful clinically.

In people, research suggests that ST John’s wort is effective in about 55% of cases. As with other antidepressants, the full effect takes approximately 4 to 6 weeks to develop. Although St. John’s wort appears to be somewhat less powerful than standard antidepressants, it rarely causes side effects.

Use of Saint John's wortmay potentiate anesthetics and other sedatives; photosensitivity has been reported in people taking high doses. The herb should not be taken with other drugs which can inhibit MAO. In people, it is recommended to take the herb with food to decrease gastrointestinal upset.

In people, the most common are mild stomach discomfort allergic reactions (mainly a rash,) lethargy, and restlessness.

Animal studies involving very large doses for 26 weeks have not shown any serious effects.

Do not combine St. John’s wort with prescription antidepressants except on the specific advice of a veterinarian, especially drugs that increase serotonin levels. Since some antidepressants, such as Prozac, linger in the blood for quite some time, caution is advised when switching from a drug to St John’s wort . The safest approach is to stop administering similar medications and allow them to wash out of your pet's system before starting St. John’s wort Consult with your veterinarian on how much time is necessary.

There has also recently been an informal report of St John’s wort lowering blood levels of theophylline, an asthma medication, in people. Preliminary investigation suggests that the hypericin in st John’s wort may increase the activity of a liver enzyme called cytochrome P-450. Because this enzyme can break down drugs, St . John’s wort may cause the body to speed the breakdown of various drugs (such as theophylline), thereby decreasing their effectiveness.

ST. John's wort (depression) may raise blood pressure, cause agitation, drowsiness, and confusion in surgical patients.

Finally, preliminary reports from the University of Colorado suggest that St. John’s wort may interfere with the action of the antitumor drugs etoposide (VePesid), teniposide (Vumon), mitoxantrone (Novantrone), and doxorubicin (Adriamycin).

Safety in young children, pregnant or nursing women, or those with severe liver or kidney disease has not been established; similar precautions in pets is probably also warranted.