The short answer: "Complementary feed" is the legal category for almost everything sold as a supplement for dogs and cats. It means the product counts as feed, not as a medicine, and falls under the EU feed rules. The rules say what must be on the packaging, what the manufacturer may promise and, most importantly, what it may not promise. That is why a serious supplement never claims to cure anything.
The legal definition
The EU feed regulation defines complementary feed as a compound feed with a high content of certain substances which, because of its composition, is sufficient for a daily ration only if used in combination with other feed1. Put more simply: it is something you give in addition to the normal food, not instead of it.
The Swedish Board of Agriculture is clear: everything given to animals as a supplement or treat counts as feed and is classed as complementary feed2. It does not matter whether it is a tablet with herbs, a syrup with vitamins or a treat with glucosamine. Same category, same rules.
Why "dietary supplement" does not exist for animals
The term dietary supplement is a food concept for humans. For animals there is no equivalent in law, there is only feed2. That is why you see "complementary feed" in small letters on the back even of products that call themselves something else entirely on the front.
Key insight: A complementary feed may support the body's normal functions. It may not claim to prevent, treat or cure disease. A manufacturer who promises more is breaking the rules, not exceeding them.
What the manufacturer may say
The regulation allows claims about optimising nutrition and supporting or protecting physiological conditions3. That is why wordings such as "supports normal digestion", "contributes to normal mobility" or "for normal coat growth" are the ones serious manufacturers use. They are not vague out of laziness, they are worded to stay within what is permitted.
Every such claim must also be objective, verifiable and substantiable. The manufacturer must be able to show scientific evidence if the authority requests it, and the evidence must exist when the product is released, not be produced afterwards3. As a buyer you have the right to report doubts about a claim to the authority3.
What the manufacturer may not say
This is the important line. A feed may not claim to prevent, treat or cure disease3,4. Such claims are reserved for medicines, which go through a completely different approval process.
So when a supplement promises to "stop diarrhoea", "heal the joints" or "cure the itching" one of two things is happening: either it is an unregistered medicine, or it is a feed that breaks the labelling rules. Neither is something you want to give your pet.
Why it is an advantage for you
It may feel as if the rules make supplements duller. In practice they make them more honest, if you know how to read them.
A manufacturer who writes "supports normal digestion" says exactly what is allowed and not a word more. That is not a sign of a weak product. It is a sign that the manufacturer knows the rules and follows them, and probably does so in matters you cannot check yourself, such as what is actually in the tablet.
Conversely: whoever promises a cure is also telling you that they either do not know the rules or do not care about them. Both options say something about the rest of the product.
What to expect from a complementary feed
Reasonable expectations, in order:
- That it gives extra of something specific. A herb, a vitamin, a mineral, in an amount that is written out.
- That it supports a normal function in a basically healthy animal, or an animal whose vet has found nothing that needs treatment.
- That it takes time. Weeks, not days.
- That it does not replace a vet, a diagnosis or medicine when those are needed.
If your pet has a problem that hurts, comes on suddenly or does not pass, it is the vet you should call, not the supplement shelf. Complementary feed is for the everyday between visits, not for the emergency room.
That was the short answer. If you have a question about your own pet, email us. We reply within 24 hours.
Read on:
Sources
- Regulation (EC) No 767/2009 of the European Parliament and of the Council on the placing on the market and use of feed, Article 3.2 j. EUR-Lex.
- Swedish Board of Agriculture, Selling feed in shops (in Swedish).
- Regulation (EC) No 767/2009, Article 13 (Claims). EUR-Lex.
- Swedish Board of Agriculture, Claims about feed (in Swedish).
Herbiovet products are complementary feed for pets. They are not medicines and do not replace veterinary care.