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Thiamine in Dogs

I recently wrote a detailed guide on dog nutrition and among the vitamins and minerals, I highlighted as some of the essential nutrients needed by dogs. One of those essential vitamins is thiamine and in this post, I have explained in detail why this Vitamin is beneficial to dogs. I have also highlighted thiamine safety, chemical composition, types, and thiamine deficiency in dogs.

Let’s start with the basics.

What is thiamine?

Thiamine is an organic compound and is also known as vitamin B1. This vitamin is water-soluble and is mainly found in plants and animals. Thiamine is essential for the metabolism of carbohydrates, fats, and proteins in dogs (and all other animals). This vitamin plays a vital role in nerve and muscle function.

Vitamin B1 is mainly found in whole grains, legumes, nuts, and seeds. Animal products such as meat, fish, and eggs are also rich sources of thiamine. Some fruits and vegetables such as broccoli, Brussels sprouts, cabbage, and spinach are also good sources of this vitamin.

Now that we know what thiamine is let’s move on and find out why this vitamin is important for dogs.

Thiamine is one of several types of Vitamin B that dogs need.

Generally, Vitamin B is essential for the metabolism of carbohydrates, fats, and proteins. This vitamin is also required for the proper development and function of the nervous system in dogs.

A deficiency in thiamine can cause muscle weakness, weight loss, anorexia, and neurologic problems such as seizures and tremors in dogs. Thiamine is among a group of Vitamin B chemical components and below are the other Vitamin B;

  • Thiamine (Vitamin B1)
  • Riboflavin (Vitamin B2)
  • Niacin (Vitamin B3)
  • Pantothenic Acid (Vitamin B5)
  • Pyrdoxin (Vitamin B6)
  • Biotin (Vitamin B7)
  • Folic Acid (Vitamin B9)
  • Cobalamin (Vitamin B12)

As you can see, thiamine is just one of the several types of Vitamin B. As the name Vitamin B1 implies, thiamine was the first Vitamin B to be isolated back in 1911.

All these vitamins are important for different purposes.

For example, Riboflavin is needed for energy metabolism, cell growth, and reproduction. Niacin helps in the metabolism of fats and carbohydrates and also aids in DNA repair. Pyrdoxin plays a role in red blood cell production, while biotin is important for fatty acid synthesis and energy metabolism.

Folic acid is essential for the proper development of the neural tube in dogs, while cobalamin is required for red blood cell production and nervous system function.

Sources of thiamine:

As mentioned earlier, thiamine is found in both plant and animal sources.

Some of the best plant sources of thiamine include; whole grains, legumes, nuts, and seeds.

Good animal sources of thiamine include meat, fish, and eggs.

Some fruits and vegetables such as broccoli, Brussels sprouts, cabbage, and spinach are also rich in this vitamin.

Thiamine can also be found in some commercial dog foods. However, it is always best to check the label to ensure that the food contains the required amount of this vitamin. In commercial kibble brands, you’ll see thiamine listed among the ingredients with the names thiamine mononitrate or thiamine hydrochloride. I’ll explain the two types in detail later.

Why is thiamine important for dogs?

As I have already mentioned, thiamine is essential for the metabolism of carbohydrates, fats, and proteins in dogs. This vitamin is also involved in nerve and muscle function. Dogs require thiamine to maintain a healthy nervous system.

Thiamine is also involved in the production of energy in dogs. This vitamin helps to convert glucose into energy which is then used by the cells and tissues of the body.

Thiamine absorption in dogs:

Immediately after ingestion, thiamine is absorbed into the bloodstream from the small intestine. The absorption of thiamine is affected by several factors such as the type of food, other nutrients present in the gut, and the health of the gut.

In the bloodstream, thiamine is immediately converted into an active form called thiamin pyrophosphate (TPP) using an enzyme called thiamin diphosphotransferase. TPP catalyzes several biochemical reactions including carbohydrates metabolism.

Below is the chemical structure of TPP:

TPP is then transported to various organs and tissues where it plays an important role in metabolism.

Thiamine is stored in limited quantities in the liver and other tissues of the body. The storage capacity of thiamine in the liver is about 30-60 mg/kg.

The half-life of thiamine in dogs is about 10-14 days. This means that thiamine is continuously being excreted in the urine and feces and needs to be replenished through diet.

Some other common names of TPP include;

Types of thiamine: mononitrate and hydrochloride in dogs

There are two main types of thiamine – thiamine mononitrate and thiamine hydrochloride.

Thiamine mononitrate in dogs

Thiamine mononitrate is the most common and most bioavailable form of thiamine. This means that it is easily absorbed by the body and used for various metabolic processes. Mononitrate has low degradation and is considered a stabilized version of thiamine. It is a wonder ingredient for dry dog food since it prevents wetness and is known to resist moisture.

Following EU regulation (EC) No 1831/2003, the EU registered thiamine mononitrate in the European Union Register of Feed Additives.

Thiamine mononitrate is a white or nearly white to yellowish granular powder with a subtle, distinctive aroma and a harsh flavor.

Thiamine hydrochloride:

Thiamine hydrochloride, on the other hand, is less bioavailable than thiamine mononitrate. This form of thiamine needs to be converted into TPP before it can be utilized by the body.

Hydrochloride is the form of thiamine that is commonly used in supplements and injectable forms. It is also used in some wet dog food formulas.

Thiamine requirements in dogs and other farm animals:

AAFCO has listed thiamine as an essential Vitamin dogs need and gave recommendations for what to feed Growth & Reproductive dogs as well as Adult Maintenance dogs. Those are the stages AAFCO classifies some kibble.

Similar to other studies such as this one by EFSA, AAFCO noted that up to 90% of the thiamine in the diet could be lost during processing. To mitigate this AAFCO recommends that kibble manufacturers give an allowance in formulation to ensure the minimum nutrient concentration for thiamine is met after processing.

They, therefore, set minimum thiamine amounts to give your dog on dry matter basis. For dogs of all life stages – growth, reproduction, and maintenance give them 2.25mg per kilogram of food. It is important that this amount is keenly adhered to as I have seen guides online indicating that AAFCO recommends that adult dog food be provided with 1mg for every 1kg of food which is wrong as this would result in thiamine deficiency.

In terms of caloric content, dogs of all life stages need at least 0.56 mg of thiamine for 1000 calories and as mentioned above, AAFCO hasn’t set a maximum limit.

Other experts including McDowell (2000) have indicated that poultry need 0.7 to 1 milligrams for every kilogram of poultry feeds. Pigs need 1 to 1.5 mg/kg, fish needs 1 to 15 mg/kg and all other pets need 0.75 to 5mg/kg.

It is important to note that homemade dog food may not have enough thiamine and if you feed your dog homemade kibble, it is important to always let your vet know so that they can give you information on supplements to use to make up for limited thiamine in your homemade dog diet.

AAFCO recommends feeding adult cats 1.4 mg of thiamine per 1000 kcalories of metabolized energy, almost three times 0.56 mg required by dogs for the same amount of metabolized energy.

Benefits of thiamine to dogs:

  1. Metabolism: Thiamine is required for the proper function of enzymes involved in carbohydrate metabolism. This is one of the reasons why thiamine is added to dog food, to help them properly metabolize the carbohydrates in their diet.
  2. Nervous system: Thiamine is also essential for the proper function of the nervous system. It helps to maintain normal nerve function and myelin production.
  3. DNA production: nucleotides, which are the building blocks of DNA, require thiamine for their synthesis.

Thiamine deficiency in dogs:

While thiamine is an essential vitamin for dogs, it is possible for them to develop a deficiency. The most common cause of thiamine deficiency in dogs is inadequate diet or poor absorption. Hospitals that treat animals with thiamine deficiency often give dogs injections of thiamine. However, this is not a long-term solution and the underlying cause of the deficiency must be addressed.

As noted in this post, thiamine breaks down with heat. In fact, a study quoted by Pet MD here noted that kibble loses 50% of thiamine content when processed. It went on to note that thiamine deficiency is common in canned wet food which undergoes intense processing.

The best way to prevent thiamine deficiency is to feed your dog a well-balanced diet that contains all the essential vitamins and minerals.

Symptoms of thiamine deficiency in dogs:

The symptoms of thiamine deficiency can vary depending on the severity of the deficiency. Early signs of thiamine deficiency include loss of appetite, vomiting, and weight loss. As the deficiency progresses, the dog may develop neurological problems such as seizures, blindness, and paralysis. If left untreated, thiamine deficiency can be fatal.

Because cats have a 3-fold higher requirement for thiamine than do dogs, they are more susceptible to thiamine deficiency.

Treating thiamine deficiency in dogs:

The treatment for thiamine deficiency typically involves supplementation with thiamine. This can be done through injections or oral supplements. In severe cases, hospitalization may be necessary. Once the deficiency has been treated, it is important to address the underlying cause to prevent a recurrence.

You can find thiamine from your vet and your vet will guide you on the dose to give your dog. They are available in 20mg (enteric-coated); 50 mg; 100 mg; 250 mg tablets. They are also available in oral powder of 500mg/oz in 1.5 lb, 4 lb, and 20 lb containers.

Harmful effects of too much thiamine:

There is no record of any toxic effects of thiamine in dogs. However, as with any vitamin or supplement, it is possible to give your dog too much thiamine. If you suspect your dog has been given too much thiamine, contact your veterinarian immediately.

Recalls of dog kibble because of thiamine deficiency

As early as 2009, pet food manufacturers had to issue voluntary or FDA-mandated dog food recalls because of limited or deficient thiamine content. A recent recall in 2017 by J.M. Smucker Company was for canned cat food brands that had low levels of thiamine.

Sources:

  1. Diamond dog food recall
  2. AAFCO Info on Recommended Thiamine
  3. https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/thiamine-pyrophosphate
  4. https://pubchem.ncbi.nlm.nih.gov/compound/Thiamin-pyrophosphate#section=Deprecated-CAS
  5. https://www.sciencedirect.com/sdfe/pdf/download/eid/1-s2.0-S0195561614000515/first-page-pdf
  6. https://www.sciencedirect.com/science/article/abs/pii/S0195561614000515
  7. https://onlinelibrary.wiley.com/doi/epdf/10.1111/bpa.12188
  8. AAFCO 2013
  9. https://pubmed.ncbi.nlm.nih.gov/16550223/
  10. https://journals.sagepub.com/doi/pdf/10.1177/030098587701400202
  11. https://avmajournals.avma.org/view/journals/javma/243/5/javma.243.5.649.xml?tab_body=previewpdf-29324