Licorice is an herbal anti-inflammatory agent often
used to achieve the same effects as corticosteroid
medications. Pets with a variety of allergic problems
may benefit from therapy using licorice.
Licorice is a fast acting anti-inflammatory agent. It is also known
for its antimicrobial and immune-stimulating properties. Many
herbalists regard it as "nature's cortisone" due to it glycyrrhizin
content, and it is often recommended for pets with arthritis,
allergies, asthma, and other inflammatory disorders. Licorice
root inhibit inflammatory prostaglandins and leukotrienes
(similar in activity to corticosteroids).
Because licorice also exhibits mineralocorticoid as well
as glucocorticoid activity, it has been suggested for use in
The use of licorice may allow pet owners to use decreased
doses of more potent corticosteroids.
Licorice is beneficial for the treatment of liver diseases
due to its ability to prevent free radical damage and inhibit
formation of free radicals. Licorice also has a protectant effect
and enhances interferon and T-cell production to boost the
Licorice reduces inflammation in pets with bronchitis and
may act as an expectorant. Licorice has also shown antibacterial
In the intestinal tract, licorice helps heal ulcers and may
decrease hydrochloric acid in the stomach.
Deglycyrrhizinated licorice (DGL) is a special extract made
by removing the glycyrrhizin molecule, leaving the flavonoid
components. In people, DGL is used for treating ulcers of
the mouth and small intestine and in inflammatory bowel
disease. The anti-ulcer effects in people have been shown to
be as effective as antacid medications such as Tagamet. DGL
is also recommended as an herbal ulcer-preventive (similar
to drugs such as misoprostol) for people taking nonsteroidal
medications and corticosteroids. However, it is not clear that
DGL provides all the same benefits as whole licorice for other
Several double-blind studies in people show benefit to patients
with HIV infection and AIDS; similar results might occur in cats
with leukemia or immunodeficiency infections.
Tinctures appear to be the preferred form in pets.
When used in large doses and for extended periods of time,
licorice can produce similar cortisone-like effects as steroid
medications, including high blood pressure and increased
serum potassium. Do not use in pregnant animals.
If used for more than two weeks at a time, side effects can
include decreased potassium (supplementing with potassium
is recommended), fluid retention, high blood pressure, and
increased sodium; increased sodium excretion may be needed.
These effects can be especially dangerous if you take digitalis,
or if you have high blood pressure, heart disease, diabetes, or
kidney disease. Licorice may also increase both the positive
and negative effects of treatment with corticosteroids, such
as prednisone. Dandelion leaf can be added to the regimen to
help increase potassium and decrease sodium. In people, side
effects occur commonly at levels above 400 mg per day.
DGL is believed to be safe, although extensive safety studies
have not been preformed. Side effects are rare.
Safety for either form of licorice in young children, pregnant
or nursing women, or those with severe liver or kidney disease
has not been established. Similar precautions are probably
warranted in pets. If the pet is taking: digitalis, long-term use
of licorice can be dangerous; thiazide or loop diuretics, use of
licorice might lead to excessive potassium loss; corticosteroid
treatment, licorice could increase both its effects and its side
Do not use in animals with cardiovascular disease, high
blood pressure, or kidney disease; in pets taking digitalis
medications; or in pets with diabetes. Licorice could increase
Licorice induces cytochrome P-450 enzymes in the liver;
this may alter the metabolism of other drugs, decreasing their
If licorice root is used for more than two weeks at a time, the
diet should be supplemented with potassium and the sodium
should be decreased. Caution should be used in animals with
heart disease or hypertension. In large amounts, steroid over
dosage (Cushing's disease) could theoretically occur. It should
not be used in pregnant animals and care must be exercised in