What is St. John’s Wort?
St. John’s Wort is an herb, prepared from the plant Hypericum perforatum, that is mainly used for treating depression and anxiety disorders in people. This is a fairly modern use of St. John’s Wort. Traditionally, the herb was used to ease the pain of peripheral nerve injuries.
Why recommend administration of St. John’s Wort to my pet?
While St. John’s Wort is typically thought of as promoting human mental health, research indicates that the herb is also anxiolytic (reduces anxiety) in some animal species. In addition, the herb is effective in laboratory animals at reducing depression and psychological stress. Because of these relaxant effects, some practitioners prescribe St. John’s Wort for mild anxiety associated with thunderstorms, visits to the groomer or veterinarian, and other mild fears and phobias.
Science has also discovered a chemical basis for the herb’s ability to relieve pain, namely a mechanism similar to opiates, which are in the same chemical class as morphine. Hypericum finds use as an analgesic in the management of intervertebral disk disease. Topical application of the essential oil prepared from St. John’s Wort may help with mild contusions, muscle aches, and minor skin irritations.
How much experience is there with the use of St. John’s Wort in dogs?
Despite the therapeutic possibilities discussed above, experience with St. John’s Wort in dogs is still limited. Doctors who have used it by itself or in herbal preparations report positive results. It is a leading prescription remedy for depression in people in Europe.
What species of animals are being treated regularly with St. John’s Wort?
Dogs and cats are treated with St. John’s Wort.
How much research has been conducted on this supplement?
While a significant amount of research has been conducted on the effects of St. John’s Wort in people and laboratory animals, research in pet animals is lacking.
How can my pet benefit from St. John’s Wort?
Pets with mild anxiety, phobic conditions, or depression may benefit. Psychogenic alopecia (hair loss resulting from psychological reasons) and even acral lick dermatitis (also called lick granuloma) might similarly benefit, given the herb’s relaxant and peripheral analgesic (pain relieving) effects. Hypericum may also be used to relieve acute back pain secondary to disk prolapse.
How safe is St. John’s Wort?
St. John’s Wort appears quite safe for use in dogs. Photosensitization (sensitivity to sunlight) is possible with extended use of high doses. Animal and human research has indicated that photosensitization is not likely to occur at the dosages typically used.
St. John’s Wort may potentiate (increase the effects of) anesthetics and other sedatives. It is typically recommended for humans that St. John’s Wort not be combined with prescription antidepressants since it has been speculated that the herb acts, like many pharmaceuticals, to increase serotonin levels in the brain. Recent neurophysiological research suggests, however, that St. John’s Wort may act at least partly through other mechanisms. 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, an asthma medication), thereby decreasing their effectiveness. St. John’s Wort may raise blood pressure, and 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 anti-tumor drugs etoposide (VePesid), teniposide (Vumon), mitoxantrone (Novantrone), and doxorubicin (Adriamycin). More research is needed in these areas.
Safety in young children, pregnant or nursing women, or those with severe liver or kidney disease has not been established. Similar precautions in pets are warranted.
Where do I obtain St. John’s Wort and do I need a prescription?
Your veterinarian may have preferred supplements that he or she will recommend. Pet owners are cautioned against buying supplements without knowledge of the manufacturer, as supplements are not highly regulated and some supplements may not contain the labelled amount of ingredients. Liquid extracts should be used for the management of immune deficiency syndromes. A prescription is not needed for St. John’s Wort.?
Based on material written by Steve Marsden, DVM ND MSOM LAc DiplCH AHG, Shawn Messonnier, DVM and Cheryl Yuill, DVM, MSc, CVH and modified with permission from Lifelearn Inc.
© Copyright 2004 Lifelearn Inc.
