Supplement does not mean harmless
Vitamins, minerals, fatty acids, probiotics, joint ingredients, botanicals, and other compounds can have biological effects. Excessive vitamin D, calcium, vitamin A, or certain minerals can be harmful, and botanical ingredients may interact with medication.
Start with the diet
If a commercial diet is labeled complete and balanced for the appropriate life stage, adding a broad multivitamin without a reason can upset nutrient balance. Homemade diets are different: they often require a specifically formulated vitamin-mineral supplement to become complete.
How strong is the evidence?
Evidence varies by ingredient, species, condition, formulation, and dose. Data supporting one product or strain cannot automatically be transferred to every product containing a similar ingredient. Look for transparent labeling and clinically relevant research.
When veterinary guidance matters most
Discuss supplements before use in pets with kidney, liver, heart, endocrine, bleeding, seizure, or gastrointestinal disease; animals receiving prescription medication; pregnant animals; puppies and kittens; and pets scheduled for surgery.