Pet Supplements: A Veterinarian's Advice on When They Help and When They Don’t
Written by Alessandro Didiano (doctor in veterinary medicine, MRCVS)
Disclaimer: This article is personally written by me, a licensed veterinarian with more than a decade of clinical experience. It’s for general information only and not a substitute for professional veterinary advice.
I was recently doing a routine consultation for a 5-year-old dog. As usual, I asked the owner if the dog was on any medications. She began confidently: “No.” Then, almost as an afterthought, she added, “Well… he’s on some supplements.”
Before I knew it, she was listing an endless string of powders to support intestinal function, pills to prevent arthritis, chews for skin and brain health, and liquids for electrolyte balance. I was quite surprised, so I asked, “Why are you giving him all of this?” She paused and said, “I don’t know… they all seem essential. Isn’t that the case?”
This situation is not unique. It highlights a growing trend in both human and veterinary medicine: the supplement craze. Supplements promise improved health, longevity, immune support, you name it, but the reality can be different.
Supplements Are Powerful, But Not Always Necessary
Pet supplements can be incredibly useful. In certain situations, they fill genuine nutritional gaps, support recovery from illness or provide proven benefits. For example:
- Glucosamine and chondroitin do indeed support joint health and may reduce the risk of arthritis.
- Vitamin B12 injections are essential for pets with digestive disorders or absorption issues.
- Probiotics can support gut health in pets with gastrointestinal symptoms.
- Calcium or magnesium may be needed during specific life stages, such as lactation.
However, healthy pets generally don’t need multiple supplements. A balanced (and obviously species-appropriate) diet usually provides all the nutrients they require. Unnecessary supplementation rarely improves health and can add extra expense, and even risk in some cases (for example, unnecessary calcium supplementations).
When to Use Pet Supplements
Supplements should be used when:
- A deficiency has been diagnosed (for example vitamin B12 deficiency)
- A specific health condition benefits from supplementation, supported by scientific evidence (for example probiotics and joint supplements)
- Dietary intake alone is insufficient, and a supplement fills the gap (for example, calcium deficiency in some lactating animals, but this has to be diagnosed with a blood test)
When Not to Use Pet Supplements
Supplements are not needed for every pet. As discussed, most healthy pets already get the nutrients they need from a complete and well-balanced diet. Adding multiple products “just in case” doesn't improve health, it just makes you poorer.
You don’t need supplements when:
- Your pet is healthy and eating a complete, species-appropriate diet.
- You’re trying to prevent problems that may never occur.
- You’re relying on marketing claims rather than veterinary guidance.
The exception I often make is for joint supplements. There is strong evidence that glucosamine, chondroitin, and omega-3 fatty acids is safe and can be beneficial even if the pet has no symptoms of arthritis, as they may help reduce risk, and slow disease progression once it appears.
The Takeaway
As a veterinarian, I treat supplements like any other medical tool: they have their place, but they are not a substitute for proper nutrition or veterinary care. A carefully chosen supplement can help a pet with a specific condition, deficiency, or life stage, but giving several products at once is rarely beneficial.
Before adding anything to your pet’s diet, ask yourself:
- Do they truly need this?
- Is there evidence it will help?
- Have I discussed it with a vet?
When used thoughtfully, supplements can support health and recovery. When used indiscriminately, they usually just take up space and add unnecessary expenses.