How Much Milk Thistle to Give to a Dog

By Tammy Dray

Milk thistle or Silybum marianum is an herb used in natural medicine to help the liver, kidneys and gallbladder. Because milk thistle is not a regulated drug, there is no standard dosage recommended for dogs, or humans, for that matter. If you are interested in giving your dog milk thistle, your veterinarian can help you determine the right dosage based on your dog's size, age and health condition.

How Milk Thistle Works

Milk thistle extract contains silymarin, an active constituent that has been used for centuries to treat liver disease in both humans and animals. Milk thistle helps in a number of ways, including anti-inflammatory actions, detoxifying and stimulating liver regeneration. Silymarin is also high in antioxidants, which help regulate and stabilize liver cells.

Benefits of Milk Thistle

Milk thistle can be used to treat a number of liver conditions, including chronic hepatitis and liver damage caused by toxins and poison, according to an article in Veterinary Practice News. It can help with gallbladder disorders. Milk thistle can be used in animals battling liver, colon and bladder cancer, as the silymarin can help reduce the chances of tumor regrowth.

Dangers of Milk Thistle

Milk thistle is available without a prescription and is considered a safe herb. However, you should never give milk thistle or any other supplement to your dog without veterinary approval. Side effects are rare but can include stomach or intestinal upset, including loose stools. A potential danger of milk thistle is that it enhances the effect of chemotherapy drugs, which could lead to chemotherapy toxicity. Dogs undergoing cancer treatment should only take milk thistle under strict vet supervision.

Milk Thistle Dosage

Because the amount of milk thistle per capsule varies according to brand, only your vet can recommend the exact dosage for your dog. However, as a general guidance, the recommended dosage is 75 to 100 mg for every 10 pounds of body weight once a day, according to the Winrock Animal Clinic in Houston, Texas. Higher dosages might be needed for dogs with severe liver problems.