Dr Trudie Prinsloo is a qualified veterinarian and attorney. In 2015, she started Legalvet services to provide legal advice to the animal and veterinary industries in South Africa – and now she’s teamed up with us to tell us all about the safety and efficacy of pet supplements.

While Dr Prinsloo is a qualified veterinarian, she cannot advise on unique nutritional needs remotely. This blog is intended for informational purposes only and should in no way be regarded as a substitute for professional veterinary advice, diagnoses, or diet plans.

dotsure.co.za is not responsible or liable for any advice or any other information provided herein. If you are concerned about your pet’s diet and nutrition, the best course of action is to consult your veterinarian as soon as possible.

The COVID-19 pandemic has caused many changes in our lives, some bad and some good.  One of the good things was raising awareness of our general health and wellbeing. People are taking better care of themselves and discussions about which vitamins and minerals to take to boost our immune systems have become ordinary.

Since pets are part of our families, people are also aware and concerned about their well-being.  I have even heard of people asking if they should provide supplements to their pets to prevent them from contracting COVID!  But just how safe are supplements for our pets? And what should we give if we want to give supplements?

Should I give supplements to my pets?

The first  question to ask is: “Why do I want to give a supplement to my pet?”  If it is just because you saw a product that looks good and sounds impressive, please stop for a moment and reconsider.

Is your pet on a balanced diet? Most commercially available diets provide adequate nutrition and would not require any supplementation.  In fact, adding supplements to a balanced diet can actually cause an imbalance.  If you feed your pet a homemade diet that has been recommended by a veterinarian or animal nutritionist, then further supplementation should also not be required.  However, if you are not sure if your pet’s diet is balanced, consult with your veterinarian or animal nutritionist to get appropriate advice before you start giving supplements.

If your pet is on a balanced diet, but you feel that there is another reason why you would want to give a supplement, such as a dull coat, or slight lethargy, or your pet is getting old and you want to make sure that you provide everything necessary for optimal health, please visit your veterinarian first and have an open discussion about this.  There might be an underlying disease and giving supplements can temporarily mask symptoms and delay a proper diagnosis.  If your pet needs a supplement, your veterinarian will be in the best position to advise you on the appropriate supplement to give after seeing your pet.

What you need to know about a supplement before buying it

There are three aspects to look at when deciding if a specific supplement should be used.

  • The quality of the supplement

This determines if the product really contains what it is supposed to contain.  For example, if it states that each tablet contains 25mg of zinc, can we be certain that it actually contains 25mg of zinc?  As consumers, we have learned to read labels, but it can be very difficult to determine whether they are accurate.

The best way to know if pet supplement labels can be trusted is to make sure they are registered following the South African law.  All nutritional supplements for pets and other domestic animals in South Africa should be registered under the Fertilizers, Farm Feeds, Agricultural Remedies, and Stock Remedies Act 36 of 1947 or under the Medicines and Related Substances Act 101 of 1965.

You will know that the product is registered in terms of the Fertilizers, Farm Feeds, Agricultural Remedies, and Stock Remedies Act if there is a number starting with a “V” or “G” on the package for example “V21477”.  If a product is registered in terms of the Medicines and Related Substances Act, the label and package insert must also indicate it.  Products that are not registered under either of these two acts, should be avoided.

  • The efficacy and effectiveness of the supplement

Efficacy and effectiveness mean that the product works in the way that it is intended to work and provides the benefits promised.  Unfortunately, there is a huge gap in research on pet supplements, and sufficient data to prove efficacy is often lacking.

There are several international publications in the veterinary literature that emphasise the lack of evidence for the efficacy of many supplements used in pets.  This does not mean that all supplements are ineffective and should not be used, but it shows how little is known and that claims are often made by manufacturers merely to sell products without having the best interest of you or your pet at heart.

  • The safety of the supplement

The safety of the product deals with aspects such as side effects and long-term risks of taking a product.  This is the most important aspect to consider when deciding to use a product.  The best way to determine this is to ask your veterinarian and only use products that are registered in terms of the South Africa law.

Please also remember that products used in humans are not always safe for pets or even necessary.  An example of a vitamin required by humans, but not by cats and dogs, is Vitamin C.  Cats and dogs can make their own Vitamin C, whilst humans need to take it in through their diet.  Human supplements are also made for the average human being which is far bigger than the average dog or cat.  Therefore, a tablet fit for a human can be a massive overdose for a smaller dog or cat and in the long term can even cause toxicities in pets.


There are many potential dangers in giving supplements to your pets, but not all supplements are bad or harmful and some have definite benefits.  To make sure that you do the best for your pet, follow these recommendations:

  • If your pet is on a balanced diet, it probably does not need any supplements.
  • Don’t be tempted to buy supplements just because they look good and sound beneficial.
  • Consult with your veterinarian before giving any supplements.
  • Use pet supplements that are registered under the applicable South African legislation.
  • Do not use human supplements for your pet, unless specifically prescribed by your veterinarian.