Your Cart is Empty

To supplement or not to supplement? Vitamin B for dogs

by Dr. Pippa Elliott November 09, 2020 4 min read

Sources of vitamin B, such as meat and fish

A regular supply ofvitamin B for dogs is essential for their good health. This is because the body can't store much, and once it's gone things start to go wrong. It's like having a motorbike with a small fuel tank; all goes well while there's gas in the tank, but once it runs out, things grind to a halt. 

The good news is that dogs fed a diet rich in meat, fish, and offal, or a good commercial product, get plenty of vitamin B from their food. But even then, there are times when the vet may suggest giving your best buddy a B-vitamin supplement, such as those four leggers with health problems involving their pancreas, liver, or gut. 

The importance of vitamin B for dogs

We know that all vitamins for dogs play important roles—but why does vitamin B complex matter?

B vitamins are vital for many of the processes that keep a fit body working. Staying healthy without B vitamins is like building a house without mortar: things to fall apart. Wherever you look in the body, vitamin B complex has a role—whether that's making red blood cells, digesting food, or ensuring a strong immune system. 

For example, biotin, inositol, niacin, riboflavin, and pantothenic acid help keep the skin flexible, moist, and strong. Without it, the coat becomes dull, hair falls out, and the skin gets dandruffy. This makes the skin vulnerable to infection and all the discomfort this brings.

Even more important is the role B-vitamins play in making proteins, such as those in red blood cells. A vitamin-B deficiency leads to anemia, lack of energy, and weakness. Then there's the part B12 (cobalamin) plays in digestion. This is so important that for a dog with gut disease, if cobalamin levels are low then the dog won't respond to therapy even if the right treatment is given. All of this gives a small flavor of the importance of vitamin B for dogs. 

How much vitamin B do dogs need?

This question has no single answer. For starters, it depends how low the dog's levels are in the first place as to how much supplement is needed to bring them back to normal. Also, not all supplements are easy to digest. This means that you might look at a supplement label and think there's plenty in it, but the active B-vitamin never manages to cross the gut into the bloodstream, and therefore doesn't benefit the dog. 

For many decades, the only B-vitamin supplement vets relied on was an injectable form. This regime meant injections containing anywhere from 250 to 1000 µg of cobalamin (depending on the dog's size) once a week for four to six weeks. At the end of this course, the vet ran a blood test to check the levels were good. 

Happily, there is now a great oral capsule that contains a highly digestible B-vitamin. The average dose is one capsule a day (depending on the dog's size) for at least 12 weeks mixed in food, which makes for an easy way to get the dog back on track. 

Can you give your dog too much vitamin B?

This vitamin group is what’s known as water soluble. This simply means if a dog is given too much of it, the excess is filtered out by the kidneys and peed out of the body. This is nice to know because it means an overdose of vitamin B is very difficult to achieve. This is not the case for all vitamins—for example, Vitamin D is toxic in excess. 

Do dogs need vitamin B supplements?

A dog bouncing with good health that produces normal poop does not need a vitamin B supplement. These fur friends get everything they need from food (with a helping paw from friendly gut bacteria, which makes small amounts of B vitamins). But there are some dogs that will benefit from a B vitamin supplement. 

Dogs that may require a supplement

There are a few reasons dogs have a vitamin B deficiency. It may happen when the dog does not get enough B-vitamins in their food or when those B-vitamins can't pass across the gut wall. 

Problems getting B-vitamins from inside the gut into the blood are more common than you might think. A common example is the dog with diarrhea that refuses to clear up. If the tummy upset goes on for long enough, the good bacteria that help digestion get beaten up by bad invaders. 

One reason the good gut bacteria are heroes is that they help make vitamin B in the gut. The bad bacteria do the bug equivalent of lounging around all day watching TV and don't make anything, which eventually leaves the gut wall deficient in vitamin B. When you remember that this is the vitamins that helps digestion, this leaves the dog caught in a vicious circle of diarrhea creating further upset. 

All that is to say that a dog suffering from food intolerance or allergy, inflammatory bowel disease, long-term gut parasites, or infection may become vitamin B deficient. Spotting this and giving supplementation is an important part of treatment. 

Other conditions that may lead to a deficiency include: 

  • Genetic disorders affecting B-vitamin metabolism—breeds linked with this include the Australian Shepherd, Beagle, Border Collie, Chinese Shar Pei, and Giant Schnauzer 
  • Long-term poor appetite
  • Liver disease
  • Lack of pancreatic enzymes (exocrine pancreatic insufficiency) 
  • Gut diseases

Signs of vitamin B deficiency

 So how can you tell when a dog may be B-vitamin deficient? The signs are general but include: 

  • Diarrhea
  • Failure to gain weight
  • Lack of energy
  • Dry, flaky skin and hair loss
  • Catch infections easily
  • Erratic behavior, tremors, or seizures

Each of these signs is enough to mean the dog should see the vet. Remember, these are only clues that a problem exists and the dog may have an underlying health problem that needs fixing. 

If you suspect there might be an issue with vitamin B in your dog, always speak to a vet first. The fact that the dog is unwell means a veterinary professional needs to check them out and make sure a problem is not missed.

The article was written by Pippa Elliot, BVMS, MRCVS on November 9, 2020.
Dr. Pippa Elliott
Dr. Pippa Elliott

Dr. Elliott graduated from the University of Glasgow, UK, with a Bachelor of Veterinary Medicine and Surgery. She has over three decades of experience working in companion animal practice and is the designated veterinarian for the Cats Protection rescue center, Harrow. In addition to hands-on work in the clinic, Dr. Elliott is an editor for small animal, veterinary textbooks from Improve International. She also writes a regular newsletter piece for the Webinar Vet and contributed to The Veterinary Times. Dr. Elliott is also qualified as an Official Veterinarian to oversee the export of animal products abroad.