Milk Thistle Dosage for Cats

Not only a noxious weed in some areas, milk thistle (Silybum marianum) is an herb used to heal liver cells, protect the liver from hepatic disease and detoxify the liver after chemotherapy or any drug (such as flea medication) that is causing side effects. Silymarin is a flavonoid compound in milk thistle known to have healing properties in the liver. Herbalists recommend using the whole herb rather than isolated silymarin, as other compounds in milk thistle unknown to science may benefit the cat. Check with an experienced herbalist or naturopathic veterinarian before giving milk thistle to your cat.

  1. Liquid Tinctures of Milk Thistle

    • Dosage of this extract is based on an approximate 80 percent concentration of silymarin. This liquid medication often comes with a dropper marked with .5 ML and 1.0 ML; the .5 ML marking equates to 10 drops of the fluid. If the recommended dosage is one drop per 2 pounds (or 1 kilogram) body weight, twice a day, then a five-pound cat would take 2.5 drops twice per day; five drops over the course of 24 hours. Dividing the dosage unevenly into three drops and two drops is acceptable. Herbal experts recommend spreading the dosage further, over three or four doses per day. Refrigerate the extract after opening, up to six months.

    Pill Supplements of Milk Thistle

    • Pill supplements containing milk thistle, in capsule or tablet form, vary. Supplements typically contain 175 mg of silymarin but can range from 50 to 500 mg per pill. Dosage for cats is around 50 mg per day; most supplements will have concentrations too high to be practical for use in cats without careful division. Look for supplements formulated for cats, not just "veterinary use." Again, spread the daily amount across three or four doses for maximum benefit.

    Acute Case Dosage

    • Cats suffering from acute liver damage may require much higher doses of milk thistle than a cat with mild liver damage, up to two to three times the normal amount. If using pill-form supplements of milk thistle, this could be up to 100 milligrams (mg) per 5-pound cat per day.