Dog Supplements - What are they and do dogs need supplements?

Humans pop vitamins for their health and they think it is absolutely necessary to do the same thing for their four-legged babies. But human parents need to understand one thing – dogs are not humans.

What are the Dog Supplements

That means dog supplements would be different from a human’s. Yes, dogs sometimes need to take supplements but only if the dog’s diet is lacking, or the dog’s health is affected in some way.

So what do dog supplements constitute? How do you know whether they are effective? Do you need to add them to homemade dog food? Read on to find out more.

What is a supplement?

A supplement can be a vitamin or a nutrient. Basically, a supplement is added to a diet to make it nutritionally complete and balanced.

For clarity of definition, examples of vitamins are vitamin C, D and E. Examples of nutrients are protein, fatty acids, calcium and glucosamine.

Dogs either cannot synthesize some vitamins, or they can but in insufficient amounts. Therefore, vitamins are best absorbed from real food, which is why an appropriate diet is crucial.

There are 2 types of vitamins: water-soluble and fat-soluble.

Water-soluble vitamins cannot be stored in a dog's body and should be consumed more often. Fat-soluble vitamins are stored in a dog's body and can last for months. Since the dog can store these, it is easier to maintain a certain level of these vitamins in the body.

While we humans need to take vitamin C regularly because our body cannot synthesize it, our dogs can. Therefore, there is usually no need to give them additional dosage of Vitamin C.

A dog’s body, however, cannot manufacture nutrients on its own. These are obtained entirely from its food.

Types of dog supplements

Supplements can be in the form of pills, powder or liquid. There are a few configurations of dog supplements:

- Single supplement – These are standalone. One bottle contains only one type of vitamin or nutrient.

- Multivitamins – These are a combination of at least 3 different types of vitamins and are sometimes combined with various nutrients.

- Natural supplements – These are made from natural ingredients either in powdered form or in the form of extracts. They do not contain fillers and artificial preservatives or colours.

- Synthetic supplements – These are created purely from chemicals and can contain fillers and artificial preservatives or colours.

When are dog supplements necessary?

If a dog is healthy and eating a nutritionally balanced and complete diet, it doesn’t need to take supplements. However, supplements may be necessary for these categories of dogs:

  • senior dogs
  • dogs diagnosed with certain medical conditions
  • dogs with a predisposed genetic weakness
  • strays that are adopted off the streets, likely to be malnourished due to poor diet
  • dogs that have been fed low-quality food

If a dog is diagnosed with a specific vitamin or mineral deficiency, the vet might recommend a single supplement and not a multivitamin.

Some illnesses can be treated with a supplement. For example, zinc is prescribed for dogs with dermatosis.

Aging dogs tend to suffer from joint discomfort. In more serious cases, they suffer from arthritis. Glucosamine-chondroitin supplements are normally prescribed to support their joints.

Do supplements work?

It depends on what the supplement is used for and how it is manufactured, veterinarians say. Not enough clinical trials have been conducted on the full range of supplements being sold in the market.

Nevertheless, some studies have shown positive effects of supplements for certain health problems.

A 2007 study published in The Veterinary Journal concluded that dogs treated with glucosamine-chondroitin sulfate showed less pain and more mobility after 70 days of treatment.

The anti-inflammatory effect of fish oil supplements has been tested. Very specific doses must be prescribed for various diseases which cause inflammation.

Fatty acids can help coats look better and reduce shedding. Antioxidants such as vitamins C and E help aging dogs with memory problems.

How do I know whether a supplement is effective?

Effectiveness is usually based on observing the pet’s appearance and behaviour. Some can be based on blood test results, depending on what the health issue is.

If it is a skin problem, there would be an improvement in the coat and skin after a period of taking the relevant supplement. If the problem is joint related, we would see the dog being able to get up faster than prior to using a supplement.

There may even be situations where a decline in the dog’s condition is noticed when the supplement is stopped. In these situations, the benefits of the supplement become obvious to both owner and veterinarian.

If a supplement is given to a dog concurrently with other supplements or lifestyle changes, it may be more difficult to perceive the benefit of that particular supplement.

For example: Benji takes supplement Y, then changes its diet from kibble to gently cooked food, and starts an exercise program. Improvement in Benji’s health may be due to any one of the factors, or due to a combination of all three.

Should I get advice from a vet before giving my dog a supplement?

Definitely. Caution must be practised in giving supplements to a dog.

Your veterinarian can help you determine which supplements are required, the dosage and which specific brands have the quality control necessary to keep the dog happy and healthy.

Veterinarians are also trained to be knowledgeable about the toxicity and predictable side effects of supplements. Ask a licensed veterinarian who is trained and knows about the supplements and about alternative medicine in general.

You are not a vet

It is never a good idea to prescribe supplements on your own, as you might misjudge or misdiagnose your dog’s problem.

Symptoms that look like arthritis, such as a dog with a weak rear end, could instead be a neurological problem. A poor coat could indicate not just skin problems, but metabolic or hormonal problems.

Toxicity and more health problems

Giving the wrong supplements for the wrong problems could lead to toxicity. Also, if it is already eating a balanced diet, excess vitamins and minerals could be harmful.

Effects of toxicity can be very serious. For example, signs associated with acute vitamin A toxicity include general malaise, anorexia, nausea, peeling skin, weakness, tremors, convulsions, paralysis, and death.

Too much calcium can cause skeletal problems, especially in large-breed puppies. Excess vitamin D can cause a dog to stop eating, harm bones, and cause muscles to atrophy. Too much vitamin A can harm blood vessels as well as cause dehydration and joint pain.

Interaction with medication

Furthermore, ingredients in some supplements may interact with other medicine a dog is already taking. Your vet should be able to advise you on this.

Can I add supplements to my dog’s food?

Yes. However, you must first determine whether it is absolutely necessary. There is no reason to do so if your dog is healthy, has no health issues, and you are giving it the right high quality food.

Dog supplements for homemade food

Homemade dog food is undoubtedly made by owners with lots of love. But that is not enough to ensure the diet is balanced and complete.

In a 2013 study from the School of Veterinary Medicine at UC Davis, 200 homemade dog food recipes were evaluated. The recipes came from 34 different sources, including pet care books, websites and even veterinary textbooks.

Researchers evaluated the ingredients used in these recipes and the instructions for preparing the food. They found that only 9 of the recipes provided the essential nutrients in adequate concentrations to meet the minimum standards set for adult dogs by the Association of American Feed Control Officials (AAFCO).

Of those 9 recipes that met AAFCO minimum standards, only 5 recipes provided the essential nutrients in adequate concentrations set for adult dogs by the National Research Council.

This meant that only 2.5% of the recipes out of 200 evaluated provided adequate nutrients for adult dogs according to the AAFCO and the NRC.

In other words, supplements may actually be necessary if you give your dog homemade food. What dog supplements you will need to use depends on two things:

(1) nutrients missing from the recipe's ingredients

(2) your dog's current health and individual needs

Unless you’re a whizz at calculating nutrient content in your cooking and diagnosing your dog’s health like a vet, it might actually be safer to buy gently cooked food that’s commercially sold.

Overdosing your beloved pooch on any kind of nutrient is as bad as depriving it of nutrients. So, if you must give your dog supplements together with your homemade food, check with your vet first.

Some of the common supplements added with homemade food are:

What should I look for on a label?

Every label should have the name and contact information of the manufacturer of the product, expiry date as well as recommended feeding directions.

It should contain information about its contents, ideally with some sort of a minimum analysis of the active ingredients and their percentages or grammage.

It should also contain information about any inert or carrier substances that are present, such as milk sugar, whey, vegetable or animal proteins.

For herbal products, the label should also include the Latin name of the plant and the amount of active constituents.

What should I do if my dog shows an unexpected reaction to a supplement?

When you see your vet about the right supplement for your dog to take, ask him or her about the expected results. That way, you would know when your dog shows an unexpected reaction, or responds in a negative way to the supplement.

The moment you observe this, stop giving your dog the supplement immediately and bring it to the vet for a check-up. Bring any of your dog’s bodily excretions that are part of its unexpected reaction. These would help your vet identify any problems your dog may have.


Dog supplements must be treated with the same amount of caution as you would medication. The reasons are many. Overdosing on a vitamin or nutrient can cause side effects; some of them serious, some less serious. The best bet is to work closely with your vet before dosing your dog with supplements.