Milk Thistle for Dogs

This amazing herb is used to treat diabetes, liver failure, and IBD.


Milk thistle (Silybum marianum) is a flowering plant in the Aster family. A native of Europe, it has been used since the time of the Roman emperors as a liver tonic. Milk thistle is one of very few traditionally used herbs that has been widely accepted by conventional science to have significant medicinal value. Using milk thistle for dogs is also believed to have a number of beneficial effects.

Today we know the active ingredient of milk thistle seed extract as a flavonoid compound called “silymarin.” Most milk thistle extracts available today contain about 80 percent silymarin.

Milk Thistle for Dogs

Silymarin, which is itself a combination of several other active compounds, has been extensively studied around the world, and has been shown to be safe and effective in treating a variety of liver diseases and other conditions. It specifically protects the liver against toxins (including some drugs and heavy metals), activates protein synthesis, and stimulates growth of new liver cells to replace those that are dead or damaged. Milk thistle also has strong antioxidant (destroys oxygen free radicals) and anti-inflammatory actions.

Silymarin reaches high levels in the bile and liver (it also reaches significant levels in the lungs, pancreas, prostate, and skin). It can be used in the treatment of hepatic lipidosis, chronic hepatitis, cholangitis (inflammation of the bile ducts), and pericholangitis (inflammation of the tissue around the bile ducts). It may be useful in preventing or treating gallstones by thinning the bile. Many dogs with inflammatory bowel disease (IBD) have concurrent inflammation of the liver/bile system and the pancreas. This suite of symptoms is called “triaditis.” Because milk thistle’s beneficial actions concentrate on the liver and bile systems, it may also be helpful in dogs with IBD.

Milk thistle should be considered as an aid to healing after drug therapy, vaccinations, and infections such as canine parvovirus, as well as an potential adjunct treatment for cancer. Researchers at Case Western University concluded from their work that “silymarin possesses exceptionally high protective effects against tumor promotion . . . ” One human study even suggests a role for milk thistle in diabetes mellitus through its normalizing effects on red blood cells. It may also help prevent diabetic neuropathy, a common complication of the disease that causes degeneration of the nerves controlling the hind limbs, which consequently produces weakness and an abnormal gait.

Milk thistle generally supports the immune system through its powerful antioxidant, free-radical scavenging action, its ability to preserve the supply of another important antioxidant, glutathione, as well as direct effects on immune cells. Glutathione, which is stored primarily in the liver, naturally declines over time, and depletion of this protein appears to accelerate the aging process.

While it’s not exactly the fountain of youth, milk thistle clearly has wide-ranging positive effects throughout the body. However, before you add this potent herb to your dog’s daily regimen “just in case” it might do some good, it’s important to consider that some herbalists believe milk thistle is best reserved as a treatment for existing disease, rather than being used by itself in a healthy dog.

While moderate use of milk thistle is very safe, there is some experimental evidence to suggest that long-term ingestion of very high dosages of milk thistle will eventually suppress liver function.

Milk Thistle Dosage for Dogs

The standard dosage of milk thistle extract is based on a silymarin content of around 80 percent; most supplements contain anywhere from 50-500 milligrams (175 mg is typical). As with many supplements, it’s probably better to buy a milk thistle derivative rather than a silymarin-only or other fractional supplement, since there may be other compounds found in the whole herb that significantly enhance the effects of what science has decided is the main player.

Because of its excellent safety record and lack of adverse drug interactions, when I’m treating a very sick dog with advanced liver disease, I do not hesitate to use up to 200 mg per 10 pounds of body weight of milk thistle extract daily. For most canine purposes, however, one-third to one-half of that dose is more than adequate. (Dogs with liver disease typically will not eat, but it’s a simple matter to open up a capsule, mix the appropriate amount of powdered herb with a little blenderized food or baby food, and feed it to the dog in a syringe.) Too high a dose can cause an upset tummy, gas, or mild diarrhea; these are easily resolved by giving less.

Human research studies have shown that it is more effective to administer this herb in three or four small portions over the day than in one large daily dose. When it is not possible to split the daily dose and administer the fractional portions three or four times a day, give it at least twice a day.

The capsule form is easy to find – any health food store, and even most pharmacies and grocers, will have them in stock. The herb also comes in a liquid extract, but most human products contain a fair bit of alcohol. If you prefer a liquid preparation, get one specifically intended for use in animals.

One safe, reliable source of a liquid extract is Animals’ Apawthecary (available through some pet specialty shops and many mail order suppliers).

Jean Hofve, DVM, is a regular contributor to WDJ. Her veterinary practice is in Englewood, Colorado.



  2. My blue pit is jaundiced and liver enzymes in the 800’s. I’m willing to do ANYthing I can to help her. Gave her 5 175mg capsules just now in chicken- the only thing she’ll eat right now. Tmrw I will split up the doses if she’ll take them. She’s already on Denamarin (stronger version of samE supplement to support liver function). Not sure if I should stop the 2 antibiotics she’s prescribed (Amoxicillin and Flagyl). Wish I could read more comments where Milk Thistle made a significant difference in a dog already jaundiced and not wanting to eat much.

    • Denamarin contains milk thistle. It is a combination of SAM-e and milk thistle (Silybin). A little over 2 weeks after starting the Denamarin my dog’s liver enzymes decreased by half. You can reduce cost by purchasing SAM-e and milk thistle separately. Talk to your vet for the dosage. My dog is only 18 pounds and I was able to find human grade SAM-e and Herbsmith USDA Organic Milk Thistle for dogs in powder form. This combo will save money. I have a few Denamarin left and then plan to give the individual supplements, Also, I changed my dog’s diet from all kibble (Orijen) to am kibble and pm a mixture of meat: chicken, chicken hearts and liver, and eggs. Grain: brown rice for one week and steel cut oats for the next. Yogurt and Cottage cheese. Mixed vegetables. I boiled the meat and steamed the veges and put them through a food processor. I believe that it was a combination of the diet and Denamarin that made the difference. I recommend that you research diet as well. Plain chicken will not give your dog all the nutrients required. Vitamin E and zinc are also recommended for liver disease. Talk to your Vet and search websites. I am a registered nurse and strongly recommend that you do NOT stop the antibiotics. My little man has a heart conditions as well. New research has discovered that a grain free diet may lead to heart conditions in dogs. That is why I added grains to the pm meal. Best of luck to you.

    • Hello. I’m checking into Milk Thistle to replace the Denmarin I hate giving to my dog. I’ve got a brother who is a vet and he treat triaditis ( which he believes my dog has) with flagyl, amoxicillin, an acid blocker and carafate.
      My vet is treating said dog with Denamarin, flagyl, and currently prednisone for 3 weeks. She’s still in an acute pancreatitis episode….2 months long. I’m tired of forcing Denmarin down her throat so I’m switching to milk thistle ASAP. My brother said the flagyl is a long term treatment. Hope this helps. I know what a frustrating problem this is

  3. My Scottish terrier is nearly 13yrs old. Had 950gram tumour removed from his liver last year, took half his liver. It came back this year and has been been on a drug which shrunk it, . Can he have milk thistle with pallidia and previcox drugs.

  4. My dog is 12 and has IBD, diabetes and a swollen liver he’s been in the vets this week hospitalised, am visiting him every evening he is on milk thistle (sillabin) and I’m hoping from what I read here regarding liver enzymes reducing by half in 2 weeks that the same happens for my Westie. His IBD and diabetes is affecting his liver and this amazing plant apparently what I have read can keep all these conditions balanced. Hope it works. Has anyone used it for diabetes or IBD with their dog?

  5. My little Dingo we saved from parvovirus when he was was hard but ever since he has had problems. Now his blood sugar is going down and 1 or 2 times a month he is having seizures. I was told to use Milk Thistle but I’m really skeptical bc it seems like everything I do takes for ever. I have him on Crave grain-free diet and do not give him table food. Except carrots for snacks. Just wondering if you guys could give me advice…

    • Skeptical because everything seems like it takes forever? Seems like many want the “now” and if it doesn’t work immediately, then it’s somehow deemed “ineffective.” Have you ever heard of the story of the tortoise and the hair? “Slow and steady wins the race.” I guess when it comes to working out, if you don’t see results immediately, then anabolic steroids are the only way to go.

  6. I was just told last week that my little Shituz has liver problems he has not been eating in the last three days
    the vet gave him apatite shots and antibiotics for the infection I have bee feeding him chicken broth liquid and baby food I am hoping that Milk Thistle will help his liver. I don’t know how damage it is but I am willing to try anything
    for my little guy.

  7. My Lab who is going on 10 years old had high liver enzymes when I took her for blood work related to a bad tooth about a year ago now. They put her on antibiotics which I didn’t want to give her but I did to remedy the problem at the time. I later noticed a fatty lipoma on her front leg which had been well hidden by her dark fur there, but as I went back through pictures and zoomed in that area I realized it had been there for a bit but had grown quickly to the point it was noticeable. Within a week or 2 one day came that the entire bottom from her elbow joint (so to speak) down was puffy appearing and another lipoma was forming. Both were freely movable and she appeared in no pain than her usual stiffness after sleeping and her groaning getting comfortable laying down. I have little doubt she also has mild arthritis. I don’t believe in antibiotics, steroids or vaccinations unless it is absolutely necessary. My personal approach and beliefs, by no means am I giving advice on that. Everyone has to make their own decisions regarding their fur babies. This prompted me to do hours of research that amounted to days worth. To tackle her liver, her lipoma(s) (prevent and break down potential cancer cells), her arthritis, general inflammation and pain, I put her on Organic Turmeric pills with black pepper extract and Milk Thistle. She has improved all around in a matter of a couple months. She sleeps again rolling onto her back like she couldn’t be more comfortable. I rarely hear her groan anymore. Her 2nd lipoma disappeared and the initial is shrinking. She wants to go for walks every day and never wants to go in when I’m worn out. I give her the pills rolled up in a piece of lunch meat and ta-da. Again, she will be 10 this July and unfortunately Labs are not known for a long life expectancy, but I feel at peace that I found what has helped her naturally and I feel truly humbled, grateful and blessed that it is working so far and so well. I don’t know what I will do the day her time comes but it is my duty to make her time here as comfortable as possible. I hope this experience helps someone else who may be dealing with some of the same problems.

    • Nicki D they have me steroids for my dogs mild collapsed trachea but one of the side effects are that she is more susceptible to infections.I have been giving her honey, chamomile and broth and researching all night for a hollistic remedy wondering if you would no or can give me advice on what has least side effects n is most natural

    • What is the dose of turmeric supplement and the does of milk thistle your lab? I have a 11 yr old lab. Current lab results show an increase in kidney function numbers but my vet said it can be corrected if I reduce the amount of protein in his diet (cooked ground turkey). My Holistic vet also recommended to give Edgar Milk Thistle, moderately (not long term, could have adverse affects on the liver bc he’s a senior). I’m now adding a higher ratio of boiled sweet potato, minced apple and canned, low sodium green beans to his twice daily meals (which also include grated carrot, spinach and egg shells crushed in the coffee grinder), plus supplements like a pre/probiotic, egg shells and flax oil for Omega 3, stinging nettle tea (1 tsp dry leaves per 10 lbs, simmer 15-20 min). FYI, Dr Andrew Jones is on youtube with short videos on pet home health care/nutrition. I never give my dogs any store bought kibble, homemade only! Lots of info on internet to read about dog food ingredients, very misleading and unbelievable. Read about Dr. Marty Goldstein DVM too. He investigated/research dog food industry years ago. I read his book 20 years ago when we were giving the family beagle Gaines Burgers (remember those red and yellow dyed patties of who knows what?) He died at 10 yrs of cancer. My Lab and two beagles today, 14 and 16 yrs, have been given homemade all of their life. I agree, antibiotics and vaccines do much harm (vet should do titer testing to avoid over vaccinating). So glad to have read your story. I am wondering what was the dose on the two products you gave your lab. Thank you.

  8. On July 04, 2020 my Lhasa apso was shown to have large masses on her entire liver. She is 10 years old. She started treatment with Liv52 DS and Milk Thistle. Today, Sept 03, 2020 her ultrasound shows an almost normal liver. I am in shock as to her recovery and I give thanks to God, the medications and the vets that took care of her. I am to continue her medication for a month again. Hoping for a full recovery when I redo her liver profile blood work and ultrasound. These drugs has really helped my baby. Hope it helps in making an informed decision to the treatment of your furry loved ones.

    • Hi Elizabeth,

      The recommended dosage for healthy dogs is approximately 2 mg of milk thistle for each pound of dog’s weight.

      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.

      Consult with your vet also. My Lhasa also is about 12lbs and her liver enzymes were very high +450. I give her 1 capsule a day which contains 175mg of milk thistle. After three months, today it’s 120. It has helped my doggie along with Liv52.

      Hope your doggie gets better soon.