How will taking supplements impact my dog?

With most supplements you will see some small changes quite quickly, as they can have instantaneous effects.
5 min read
Dr Joe Inglis BVSc MRCVS
Head of Veterinary Sciences

In the modern world, taking supplements to help support and promote our own, and our pets’, health is pretty commonplace. However, despite all the science behind many supplements, there isn’t always much information available on the impacts that we should expect to see when we, or our pets, start taking these products.

One of the main issues a lot of people run into when taking supplements or giving them to their dogs is this: we are used to modern medicine, where beneficial effects can often be seen almost instantaneously, or at least within a few days of taking a medication. If we need antibiotics then usually the pain or symptoms of disease will start to improve within a few days. With anti-inflammatories, the pain-relieving effects can be seen within a matter of hours or less. This is not usually the case with supplements; supplements are working to improve health slowly, and at a pace that matches the pace at which the body works and that it can heal itself. This means that if you take a supplement for a couple of weeks, then in most cases you won’t see any major differences - but that doesn’t mean you or your pets should stop taking it.

With most supplements, especially herbal supplements, you will see some small changes quite quickly, as they can have some instantaneous effects. Think of that calmness that you get when you drink a cup of chamomile or another bedtime tea blend at the end of the day. However, you also get a cumulative effect over time, where herbs will build up to their maximum effect over around 6-8 weeks. From this point on you can then see further beneficial changes as the body gradually starts to correct itself and get back to its normal healthy functioning. In the grand scheme of things, waiting a few months for a resolution to a disease makes much more sense than just a few days, as chronic diseases in particular take a long period of time to resolve. What conventional medications can do in that time is help to take away symptoms, but they don’t always resolve the underlying disease, whereas supplements can act to promote the healthy and normal functioning of the body, or whichever system they are targeting, which in turn can lead to gradual resolution of the disease. Obviously, some diseases cannot be fixed at all, let alone with supplements, so we shouldn’t delude ourselves that a supplement is just a slow-working magic pill. 

One of the most exciting areas of supplementation is the development of products that influence the microbiome such as pre, pro, and postbiotics, and we are just starting to understand how they work to affect not just gut health, but many other body systems as well. We know that these compounds work to slowly correct imbalances within the microbiome to improve microbial diversity and gut wall health, and as a result, impact many other areas of health from joints to the immune system. However, as with herbal supplements this is not something that will happen overnight. It is going to take at least a couple of months to see any significant long-lasting change, although some changes may be seen within a much shorter period. 

Every dog is different, however, so if a dog has only a mild dysbiosis (imbalance in the microbes in the intestine) or problems that have only been present for a short period of time, then corrections will be seen more quickly than with those who have severe or long-term problems. Dogs with long-standing problems may also be at greater risk of quick recurrence of symptoms if they stop taking their supplements too early, as long-term changes had not been cemented into the system. Those with milder or more recent disease may take a while before their issue impacts them again, or their problem may have corrected itself. This is where retesting the microbiome is really beneficial, as then you know exactly what is happening and what is still needed to help return your dog to health. 

What about side effects? Like anything that you or your dog consumes, there is a chance that an individual can have an adverse reaction to an ingredient in the supplement.  It could lead to an upset tummy, with vomiting or diarrhoea, or cause another symptom, such as itching. Sometimes this is a short-term change which slowly goes away, whereas for others it might be that something in the supplement just cannot be tolerated by the dog. If the latter occurs then a supplement should be stopped after speaking with a vet. Each individual ingredient of the supplement could have its own side effects too, but with supplements, compared to conventional drugs, these tend to be much milder and less common. 

Probiotics themselves can give side effects in certain individuals. Although they are very minor in most, they can be more severe in those suffering from a serious illness or with compromised immune systems. In some individuals, an increase in gas, bloating, constipation or thirst can be seen after starting probiotics, but this usually resolves within a few weeks[1]. Some bacterial strains, such as Streptococcus thermophilus and Lactobacillus helveticus, produce histamine, leading to increased levels in the body. In most cases this does not cause an issue as the body balances this out, but some individuals with a histamine intolerance can show allergic type symptoms such as itching and inflammation. As mentioned above, a dog may be intolerant or allergic to other ingredients in the probiotic supplement. In very rare cases in people with immunosuppression, or following prolonged hospitalisation or surgical procedures, they have found that probiotics cause an increased risk of infection, with 1 in 1 million people developing an infection after taking Lactobacilli bacteria-based probiotics[2]

So, the take home here is to make sure you know exactly what is in any supplement that you take, or give to your dog, and to stick with it for a decent amount of time before expecting to see significant results. Also remember that, in the case of probiotics or microbiome supplements, retesting your dog’s microbiome is the best way to know that you have made long term beneficial changes to your dog’s health.


[1] Williams NT. Probiotics. Am J Health Syst Pharm. 2010 Mar 15;67(6):449-58. doi: 10.2146/ajhp090168. PMID: 20208051.

[2] Borriello SP, Hammes WP, Holzapfel W, Marteau P, Schrezenmeir J, Vaara M, Valtonen V. Safety of probiotics that contain lactobacilli or bifidobacteria. Clin Infect Dis. 2003 Mar 15;36(6):775-80. doi: 10.1086/368080. Epub 2003 Mar 5. PMID: 12627362.

GutDiscovery® Test + Gut Health Report

Ready to start your BIOME9 journey?

Order GutDiscovery® Microbiome Profile Test Kit

Frequently asked questions

  • The microbiome is the name given to the collection of microbes, mostly bacteria, but also fungi and protozoa, that exist within your dog’s gut. It is a diverse and complex microbial community which can directly affect health and wellbeing. We know that 90% of a human’s body cells are microbes, with only 10% being human cells – it’s just that human cells are markedly larger than the microbes. It’s similar for our four-legged friends. Testing the microbiome gives us an idea of exactly which bacteria are present in your dog’s gut and this can help indicate existing or future health problems.

  • A healthy diversity within the microbiome has been found to be an accurate indicator of overall health and wellbeing. If your dog appears healthy, but has an imbalance in their microbiome, then this could be an indicator of a potential future health issue. If your dog has any existing health complaints, then improving the health of their microbiome can help to improve immune system health and overall wellbeing, as well as improving disease symptoms.

  • Testing and treatment have the potential to help with a whole range of different health complaints. The immune system is very closely associated with the gut, so any imbalance in the microbiome can influence immune system health, overall vitality and wellbeing. Our supplement recommendations are also tailored to your individual dog, with specific ranges designed to help with gastrointestinal inflammation, joint problems, allergies and skin complaints, to name a few.

  • All you need to do is order a kit online and fill in our questionnaire about your dog and their general health. We will then send the kit out to you by post. You then just need to collect a sample and return it to us, again by post. Once the test is performed, we will email the results directly to you.

  • You do not need to get your vet’s permission to test, or talk to them about performing the test beforehand. We do recommend that you pass on a copy of your test results to your regular vets, as it may help them in understanding your pet’s current health, and any future complaints they may have.

Still have questions? Speak to an expert
Get in touch

Get in touch with our team to talk about our microbiome test kit, precision supplements, and more.

Continue reading

Related articles