Milk Thistle as an Antioxidant

• Milk thistle's antioxidants are more potent than those of vitamin E, according to Holistic Pet. They scavenge free radicals, increase glutathione levels (important in protecting organs) and inhibit leukotrienes, which are inflammatory agents.
  
  

Liver Regeneration

• Milk thistle helps heal and regenerate the liver by stimulating the production of new liver cells damaged by disease or toxins, to which cats are particularly vulnerable.
  
  

Liver Toxicity

• According to Holistic Pet, the silymarin compound can block toxins from entering the liver and remove them at the cellular level. Milk thistle is used to help cats through toxicity poisoning from insecticides, pesticides, mushrooms and certain drugs.
  
  

Side Effects

• Experts do not believe milk thistle is toxic when taken at the dosages recommended by vets, according to Pet Education, which may vary by individual cat. High levels may produce loose stools, however.