Harmful Side Effects of Dog Vitamins & Supplements

When a dog or any other pet eat good food and take proper sleep, play/exercise daily, generally he does not have to take any extra supplements. You probably give your dog extra vitamins mainly when he is ill, and you think that vitamins may help him get fitter.

Apart from that, when you feel that your dog should get all the supplements to stay healthy, you feed him additional stuff in the form of powder or chewable tablets.

Well, it is great that you are trying to be the best pet parent in the world and don’t want to compromise even a bit when it comes to their overall health and development. But, let me tell you that not all vitamins and supplements are healthy for your pooch.

Your beloved companion may get some adverse side effects from the dog vitamins, and it can even get serious sometimes. In this article, I am going to talk about how the overdose of vitamins can be poisonous for your furry friends. Let’s start with the basics.

Side Effects of Dog Vitamins

Each vitamin has its pros and cons when we talk about a pet. To keep the format simple, I am making a list of vitamins with its possible side effects on your pooch. You can also confirm it with your vet as he may know your furry baby inside out.

1. Vitamin A

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Vitamin A is essential for a dog’s growth and immune system. It is also crucial for vision. If there is an overdose, then it can become toxic and liable for dehydration, night blindness, and weight loss. Your dog may also experience hair loss, joint pains, and muscle weakness. He may feel like puking all the time. Excessive vitamin A can also lead to paralysis or death.

2. Vitamin B6

We all know how much it is important to have vitamin B in our bodies. Just like ours, our furry friends also need it to maintain Glucose level and to keep the red blood cells functioning well. When it exceeds the maximum amount of vitamin B6, it may affect the nervous system and hormones.

Your dog may feel dizziness and can’t keep the balance. He may get confused with the coordinations and get a sudden violent movement inside his limbs.

3. Vitamin B3

There is one more vitamin known as Niacin. Basically, it is Vitamin B3 that is helpful to a dog’s diet. It works best as it produces the enzymes. But, too much supplement can become too toxic, and your canine may not accept it.

It can be a significant reason for diarrhea that may have blood in it. Inflammation of the throat, lips, and increased salivations are also common symptoms of B3 overdose.

4. Vitamin D

Vitamin D is Much Needed for the absorption of Calcium. Being human, we can get it from the dairy products and sun rays, and so do the animals! But when they get too much vitamin D, they may experience hypercalcemia.

It is a disease that can weaken the bones. Overdose can also destroy the vitamin E inside, which eventually deteriorates the muscle fibers. Apart from that, nausea, diarrhea, and dehydration are also some common side effects of vitamin D for the dogs.

5. Vitamin E

Thankfully, there are no severe side effects of vitamin E. As you know that this vitamin is needed for the circulatory system and healing procedures. If it is given in excessive amounts, your pooch may feel lethargic and may not enjoy any activity or playing/exercising sessions. Vitamin E and C generally work as an anti-oxidant. Add these vitamins in your dog’s diet without fail. Just don’t go beyond limits.

Side Effects of Other Dog Supplements

Apart from the vitamins mentioned above, some dogs are also allergic to excessive Calcium, Sodium, and Iodine. Too much Calcium doesn’t provide stronger bones. In fact, it weakens them. It can make the bones brittle and damage/break it easily.

On the other hand, Sodium increases the dog’s heart rate and blood pressure. It can also make the dog much thirstier than usual. Excessive amounts of Iodine is liable for the enlargement of the thyroid gland. It can be the reason of your pooch’s dry coat and extra weight loss.


I do not deny the fact that sometimes a dog really needs health supplements even if his diet is well maintained. But we need to stop being overwhelmed seeing all the supplements such as minerals, vitamins, omega oils, and probiotics in the pet store.

It is time to be realistic and to know the facts. Also, nothing can be compared to the positive effects of a complete, wholesome food that contains all the necessary nutrients. Never let yourself to feed unnecessary medication and extra supplements to your favorite animal. Don’t take stress, live with the flow, and keep it simple silly. You got this! 🙂

Author Bio : I am Rachel Brier – blogger by choice. I love to discover the world around me and share my discoveries as well as experiences. I love to write about automotive, gardening, science, travel, technology and much more. Check out my blogs to know more.