What does milk thistle do for dogs

Milk thistle extracts for dogs and cats

Milk thistle supports the liver metabolism in dogs and cats.

Liver disease

Milk thistle has been used for thousands of years for liver diseases and to support detoxification in animals and humans. But what can the medicinal plant do? And what should be considered when buying milk thistle extracts for dogs and cats?

The seven most important effects of milk thistle

Researchers identified it as early as the late 1960s Silybin as the main effective ingredient in the milk thistle fruits (which look like seeds). Silybin and some similar molecules are used today under the term Silymarin summarized. Silymarin is:

  1. antioxidant
  2. anti-inflammatory (anti-inflammatory)
  3. choleretic
  4. promoting regeneration
  5. liver protective (hepatoprotective)
  6. scar-inhibiting (antifibrotic)
  7. Strengthens the immune system (immunomodulatory)

1. Silymarin is an antioxidant

Many liver diseases cause oxidative stress in the liver tissue. This serves, for example, to ward off infectious pathogens in acute illnesses, but can become independent and in chronic liver illnesses contribute to the destruction of more and more liver tissue. Silymarin from milk thistle seeds can neutralize free radicals and thus counteract oxidative stress. It can help protect important cell structures such as DNA and the cell membrane from free radical damage. In addition, silymarin is able to inhibit enzymes that are involved in the formation of free radicals and promote the formation of protective molecules (e.g. sirtuins). Last but not least, it activates the body's own antioxidant systems such as superoxide dismutase.

2. Silymarin inhibits inflammation

Among other things, silymarin inhibits one of the most important pathways in the inflammatory reaction, the activation of the so-called NF-kappaB transcription factor. This promotes the formation of inflammatory enzymes and messenger substances, which can become a problem in chronic liver diseases.

3. Silymarin stimulates the flow of bile

It ensures that more bile salts are pumped into the bile and thus promotes, for example, fat digestion and the elimination of toxins bound to bile salts.

4. Silymarin promotes liver regeneration

As early as the 1980s it was shown that silymarin promotes the regeneration of the remaining part of the organ after a partial removal of the liver. To date, it is not fully understood how this works exactly. Presumably, increased protein production through silymarin helps to regenerate damaged liver cells and to form new ones.

5. Silymarin protects the liver tissue

It suppresses the formation of cell-damaging cytokines and blocks the absorption of toxins into the liver cells.

6. Silymarin inhibits scarring

Liver fibrosis, also known as shrink liver, is a dreaded complication of many liver diseases. Destroyed liver tissue is replaced by scar tissue. But the more scar tissue there is in the liver, the worse it can do its job. Silymarin inhibits the development of the cells that make up the scar tissue (myofibroblasts).

7. Silymarin is immunomodulatory

In autoimmune-related liver diseases, i.e. when the immune system itself attacks the liver, silymarin inhibits the destructive activity of certain immune cells (T lymphocytes).

In various studies, silymarin stimulated the innate and the acquired immune system, thus strengthening the immune system.

The role of milk thistle extracts in liver disease has been best researched, but there are other interesting uses as well. For example, dogs treated with milk thistle extract and an antibiotic showed with a Giardia infection fewer side effects of antibiotic treatment. Silymarin reduces insulin resistance in people with diabetes. Thanks to its antioxidant and cell-protecting properties, silymarin is also being intensively researched in connection with neurodegenerative diseases such as Parkinson's and Alzheimer's.

How does milk thistle help dogs and cats with liver disease?

Many animal nutrition experts recommend milk thistle extracts as part of special liver diets. Above all, they rely on the antioxidant and anti-inflammatory properties of milk thistle and have had good experiences with their patients in practice. Unfortunately, there are too few clinical milk thistle studies for our pets so far to be able to make clear statements about certain liver diseases in dogs and cats. So far, much has only been researched in cell cultures, laboratory animals and human patients, with different milk thistle extracts in different dosages. Although the effects of Silimarin described above were also shown in the various species, it is only possible to a limited extent to transfer the results to animals with liver disease. What is certain, however, is that milk thistle extracts are very well tolerated.

What to look for when buying milk thistle extracts

Milk thistle extracts vary widely in quality. Silymarin is poorly absorbed by the body, so it has a low bioavailability. One feeds pure milk thistle powder (with 1.5 to 3% silymarin), no silymarin is usually detectable in the blood. For milk thistle extracts, the 70 to 80% silymarin contain little silymarin in the blood, but significantly more in the bile, since silymarin is enriched there. Thanks to intensive research, it is now possible to improve the absorption of silymarin many times over, for example by coupling it to lecithin. For some of these extracts with higher bioavailability There are already studies that confirm good uptake in dogs, including the one described in Dr. Hölter Heparvet used milk thistle extract.

If you buy a product with milk thistle extract, it is best to choose an extract whose bioavailability has been specifically improved or pay attention to a standardized high silymarin content of approx. 80%. As a general rule: the further up the list of ingredients milk thistle is mentioned, the more it contains. But since you cannot compare pure milk thistle powder and an extract with increased bioavailability, this hardly helps you in assessing the quality. If only milk thistle extract is declared without further details, it is best to ask the manufacturer more precisely.

We usually recommend one Diet supplementary feed for animals with liver disease to choose if you are looking for a milk thistle product. These meet certain legal requirements for their composition (e.g. a high content of essential fatty acids) and may bear the note “To support liver function in chronic liver insufficiency”.

If you want to buy milk thistle for your dog or cat with liver disease, it makes sense to choose a diet supplement that supports the liver metabolism, for example with omega-3 fatty acids.

How is milk thistle dosed for dogs and cats?

For Silimarin, experts recommend a dose of 20 to 50 mg per kg of body weight and day. In the case of milk thistle extracts with specifically increased bioavailability, a significantly lower dose may be sufficient. Since the milk thistle products are so different, the dose in the products cannot be compared with one another based on the list of ingredients. Again, only asking questions helps if you want to know exactly.


Milk thistle supports liver function in a number of ways and is often recommended by veterinarians. Nevertheless, there is still a need for research in dogs and cats with liver disease. Diet feed supplements that also contain milk thistle are best suited for animals with liver disease.

In addition, the diet should be adapted to the changed liver metabolism, with a diet food such as Royal Canin Hepatic or Hill's l / d:



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