In May 2017, a popular cat food was withdrawn from the Australian market after fears it was making cats seriously ill with symptoms of thiamine deficiency.
This wasn’t an isolated case. In recent years, several commercial cat food have been recalled worldwide due to insufficient levels of thiamine.
Let’s explore what thiamine is, why it matters so much for cats, and how to spot and prevent a thiamine deficiency in cats.
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What is thiamine?
When cat food recalls make headlines, pet owners are left devastated and confused. How could a simple vitamin cause such serious illness?
To clarify, we’re talking about thiamine (vitamin B1)not taurine, which is an amino acid. These two essential nutrients have been different roles:
- thiamine deficiency affects the nervous system and causes neurological (nerve related) problems
- taurine deficiency affects the heart and eyes, leading to dilated cardiomyopathy (a heart disease) and blindness.
Thiamine (vitamin B1) is essential for your cat’s energy metabolism and nervous system. Cats can’t make it themselves, so it must come from their diet.Because vitamin B1 is water soluble , it isn’t stored in the body – any excess is passed out in their urine. This means your cat needs a steady supply of thiamine every single day.
Thiamine is especially vital in diets that include carbohydrates. Think of it as the spark plug that helps your cat’s body turn carbs into usable energy. When a diet is high in grains or starchy vegetables, the body burns through thiamine faster. If that same diet is also low in thiamine, it’s a double blow – your cat is using more of the vitamin while not getting enough to replace it.
Foods high in thiamine
Thiamine naturally occurs in foods such as whole grains, vegetables, legumes and organ and muscle meats like liver and heart. Other muscle meats such as chicken or beef are relatively low in thiamine – so if you’re feeding a raw food diet, it’s important to include organ meats as well.
Here’s how much thiamine (mgs) per ounce (28.35 grams) in you’ll find in raw chicken parts:
- Chicken liver – 0.086 mg
- Chicken heart – 0.043 mg
- Chicken thigh – 0.022 mg
- Chicken breast – 0.019 mg
Other good sources of thiamine include pork, duck and salmon. For example, raw pork loin has 0.280 mg, raw duck meat has 0.102 mg, and wild salmon has 0.064 mg of thiamine per ounce (28.35 grams). These proteins can be included in your cat’s meal rotation but shouldn’t be fed every day.
Thiamine deficiency symptoms in cats
Early signs of thiamine deficiency in cats often start with digestive upset: loss of appetite, drooling, vomiting, diarrhoea or weight loss.
As the B1 thiamine deficiency in cats worsens, the nervous system becomes affected. You may notice neurological symptoms such as:
- stumbling or uncoordinated walking
- circling or “drunken” movements
- head hanging low (or held very high)
- head tremors or tilting
- eyes flicking side to side
- dilated pupils
- seizures or even coma in severe cases.
What causes thiamine deficiency?
Thiamine deficiency in cats can stem from either health issues or dietary imbalances.
Gastrointestinal diseases
Conditions like inflammatory bowel disease or stomach cancer, can thicken the gut wall, reducing the absorption of nutrients – including thiamine.
Passing a lot of urine
Cats with diabetes or kidney disease often drink and urinate more. This can flush water-soluble vitamins like thiamine out of their system faster than normal, and create a vitamin B1 thiamine deficiency in cats.
Raw fish diets
Certain raw fish and shellfish contain thiaminase, an enzyme that destroys vitamin B1. Cooking eliminates thiaminase, so this problem only occurs with raw fish. Salmon and cod are safe, but raw tuna should be avoided so watch for these fish ingredients in commercial canned cat food.
Meat only diets
Muscle meat alone doesn’t supply enough thiamine. Cats on unbalanced raw or home-cooked diets risk developing deficiencies unless the food is properly supplemented.
If you’re feeding a homemade raw meals, you MUST ensure your recipe is balanced with the right combination of nutrients (vitamins, minerals, fats and amino acids) including thiamine.
The balanced homemade raw recipe we use and recommend includes muscle meat (heart) and organs (liver and kidney) as well as a vitamin supplement mix. There are also balanced pre-mix meal completers available including EZComplete (United States) and Raw Meow Mix (Australia).
Manufacturing problems and pet food recalls
Thiamine loss can happen in a few different ways during pet food production – especially when ingredients are exposed to high heat, treated with preservatives like sulphur dioxide, or mixed with additives such as thickening agents that alter the food’s pH (acidity).
As much as 50% to 100% of the thiamine present in raw meat can be inactivated by one or more of the[se]… processing methods.
Dr. Eliza Katz, Veterinarian | Feline-Nutrition.org
Each of these processes can damage or destroy the natural vitamin B1 found in meat, leaving the finished food with much lower levels than intended. This has led to cat food recalls over the years, and resulted in vitamin B1 deficiency in cats around the world.
Diagnosing thiamine deficiency in cats
When a cat shows neurological signs, your vet will consider several possible causes including infections like toxoplasmosis, lead or heavy metal poisoning, inflammatory conditions (such as encephalitis or meningitis) and thiamine deficiency.
To narrow things down, your vet will run tests to confirm or rule out the most likely causes. If those results don’t provide clear answers, they can measure your cat’s thiamine levels with a blood test. In many cases, though, vets prefer to start thiamine treatment straight away and watch for improvement. This approach – called a “response to treatment” diagnosis – is often faster and can give your cat relief while waiting for lab results.
Treating thiamine deficiency with supplements
Treatment for thiamine deficiency in cats is straightforward: vitamin supplementation. Cats are usually given thiamine injections for 3–5 days, followed by oral supplements and care given at home.
Thiamine supplementation is available as a tablet or syrup, and is available in general multivitamin products. The recommended dose is 5–30 mg per cat per day, up to a maximum of 50 mg daily. Because cats can’t store excess vitamin B1, any extra is simply passed in the urine – but it’s still best to follow your vet’s dosing advice.
With prompt treatment, most cats recover fully within days to weeks. The key is catching it early and addressing any underlying diet or health problems.
Final thoughts
Thiamine deficiency in cats is entirely preventable – but it can have serious, even fatal consequences if missed. Feeding a balanced, species-appropriate diet and avoiding raw fish or unbalanced meat-only meals is the best protection.
If you ever notice odd behaviour, balance issues, or loss of appetite in your cat, don’t wait –call your vet. Thiamine deficiency responds beautifully to treatment, but timing makes all the difference.
