How does it work? When the constituents of milk thistle are absorbed, they selectively accumulate in the liver. The herb has several mechanisms of action. 1) It stimulates protein synthesis, which contributes to re-generation and replacement of liver cells. 2) It helps protect the liver against poisoning by blocking the absorption of toxins into liver cells. 3) It inhibits the formation of inflammatory substances that contribute to liver degeneration. 4) It helps the liver break down toxins. 5) Milk thistle is a potent anti-oxidant (more potent than Vitamins C and E). This means it can counteract free radical damage that can cause degenerative diseases including cancer. 6) It increases intracellular levels of glutathione, a substance necessary for detoxicating reactions. Milk thistle has a long history of use and no significant toxicity has been seen.

Clinical studies in humans have confirmed milk thistle's benefits. Trials in more than 2,000 patients showed benefits in alcohol and chemical induced fatty liver, cirrhosis, chronic hepatitis, bile duct inflammation and non specific changes in liver tissue. Elevated liver enzymes (blood tests for liver function) also improve with milk thistle therapy. Silymarin may also help prevent or treat gallstones by increasing the solubility of the bile. The best-known active compound in milk thistle is silybin. It is important to remember that there are many other naturally occurring ingredients that are vital for optimum activity. Therefore, use the whole herb or a high quality extract.

Many drugs used today have significant liver toxicity. If your pet has been medicated with antibiotics, cortisone, chemotherapy, anti-seizure medications, heartworm preventive/treatment, anti-inflammatory, etc. or has had other liver problems, you should consider a course of milk thistle. Of course, it is also important to reduce your pet's exposure to liver toxic substances. Most drugs can be eliminated under the supervision of a holistic veterinarian through the use of natural alternatives. Toxic additives in the food and water can be reduced significantly by feeding balanced, home-prepared foods and purified water. A low toxicity flea control program can be instituted until the pet is healthy enough to no longer require it. (That's right, healthy pets don't have significant flea problems.) For household cleaning, vinegar and hydrogen peroxide are two safe alternatives.

When shopping for milk thistle, I prefer a standardized (70 or 80% silybin) product. A typical adult human dose is 100 - 150 mg. of silybin, which is approximately 200 mg. dry herb three times daily, or the equivalent in a liquid. For pets, simply use their body weight as a percentage of the human dose. For example, a 30-pound dog would get 30% of a human dose and a 10-pound cat would get 10%. Most products purchased at health food stores have the recommended human dose on the label. Give it for 2-3 months. Medicinal herbs should not be used continuously for extended periods. I suggest 5 days on then 2 days off for 6 weeks. Skip 1 week and begin again. It could be used one week each month as a little extra protection in otherwise healthy pets.

Russell Swift is a 1985 graduate of the University of Florida College of Veterinary Medicine. He has completed the Homeopathic Master Clinician program and currently has a holistic house call veterinarian practice in the South Florida area. He is also a consultant for several companies in the development of new nutritional supplements for pets. Dr. Russell Swift can be reached at 954.720.1624.