How much Milk Thistle do you give a dog with elevated liver enzymes?

The dosage amount will depend on if you are treating a specific issue or preventing liver damage. For elevated liver enzymes, there might be a specific liver dysfunction happening so you’ll want to work with your Vet on proper treatment. Dosage for addressing poor liver function and repairing damage is between 7-20mg per pound. (Dosage is for Milk Thistle Extract with 80% Silymarin.)

Here’s an example: a dog or puppy that weighs 3lb would take 21-60 mg per day. Max dosage is 20 mg, 3 times per day. Check with your Vet before using this high dosage.

If you want to prevent harmful build-up of toxins and support the liver. You may want to do a liver flush or detox once or twice a year for 3-6 weeks. That only requires a small dosage of milk thistle. The recommended dosage for detox (flushing toxins) is 3-7mg per pound. For example:  a dog or puppy that weighs 3lb would take 9-21 mg per day. Or 7 mg, 3 times per day

A good maintenance dosage, if your dog has Chronic Liver Disease or poor liver function, is 7 mg per pound.

For example:  a dog or puppy that weighs 3lb would take 21 mg per day. Or 7 mg, 3 times per day Again, check with your Vet before using the highest dosage.

Milk thistle is regarded as very safe for use in dogs, it has an excellent safety record and lack of adverse drug interactions. If you do give too high a dose, it can cause an upset tummy, gas, or mild diarrhea; these are easily resolved by giving a smaller dosage multiple times a day.

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.

I was told by a herbalist to give Milk Thistle at night before bed because the liver does it’s cleanup at night and adding Milk Thistle will give it extra support to do its job.

The Forever Dog book lists Milk Thistle and says: “This herb should be pulsed (given intermittently) for maximum efficacy.”

One example of this is to give it daily for 3 to 6 weeks, then take a week break, and repeat if needed.


Milk thistle (silymarin) is the go-to liver detox herb: For an overview of milk thistle and key references, see its entry on the National Center for Complementary and Integrative Health’s website at

Milk Thistle for Dogs:


How do you pick the best Milk Thistle product for your dog?

Step 1: Start with how much your dog weighs and determine a dosage of milk thistle extract.

Step 2: Break the dosage down into 2 or 3 smaller dosages so you can give it 2-3 times per day.

Use the dosage calculator above.
Eg. Your dog weighs 30 pounds. The recommended (liver disease) dosage for your dog is 300-600mg.
Divide 300mg by 2 = 150mg given twice a day
Divide 300mg by 3 = 100mg given three times a day
Maximum dosage of 600mg = 300mg given twice a day
Step 3:
Look for a milk thistle product that has the right potency for your dog’s weight.  Ideally,  find one that has half the daily dosage you require so that you can give one capsule twice a day. If you have a large dog and need a large dosage. Look for one that is a third of the daily dosage so you can give one capsule three times a day.
If your dog’s divided dosage (2-3 times a day) is less than 150mg of milk thistle seed extract, pick a liquid product that can be broken down into small dosages. Or choose a pet product (powder, liquid or chewable) that comes in smaller dosages.
If your dog’s divided dosage (2-3 times a day) is greater than 150mg of milk thistle seed extract, choose a human product with a potency amount that you can give 2-3 times a day.

General Guidelines and Examples:

Dog’s Weight    Extract Potency                # of times a day
1-14lbs                liquid – 1 drop per lb         two or three times a day
8-14lbs                150mg                                 once a day
15-20lbs              150mg                                 once or twice a day
21-25lbs              150mg                                 twice a day
26-30lbs              150mg                                 two or three times a day
31-37lbs              150mg                                 two or three times a day
25-30lbs              250mg                                 once or twice a day
31-35lbs              250mg                                 twice a day
36-40lbs              250mg                                 three times a day
40-50lbs              375mg                                 twice a day
51-60lbs              375mg                                 three times a day
61-75lbs              400mg                                 three times a day
68–75lbs             450mg                                 twice a day
76-90lbs              450mg                                 three times a day
>90lbs                  450mg                                 two capsules twice a day
Step 4: Pick a name brand product with a potency in your dog’s dosage range.
Here are a few safe and reliable pet brand names:
Here are a few examples of human products:
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