In May 2017, a popular cat food was withdrawn from the Australian market amid fears it was causing cats to become seriously ill with symptoms of thiamine deficiency.
This wasn’t a one-off incident. In recent years, there have been several recalls of commercial cat food around the world, due to insufficient levels of thiamine.
Let’s take a look at everything you need to know about thiamine deficiency in cats.
What is thiamine?
In the wake of cat food recalls, pet owners are often left with huge vet bills, or in the worst case, the tragic death of a beloved cat. Cat parents want answers. How could this happen? What is thiamine and why is it important for cats?
To clarify, we’re talking about thiamine (a vitamin) rather than taurine (an amino acid) deficiency. The difference is that:
- thiamine deficiency causes neurological (nerve related) problems
- taurine deficiency causes dilated cardiomyopathy (a heart disease) and blindness.
Thiamine is actually vitamin B1 and it is essential for cats to ensure optimal health and nervous system function. This vitamin must be part of their diet because cats can’t make it for themselves. Vitamin B1 is a water soluble vitamin, meaning that it passes through their body and any excess is removed in their urine. Cats do not store vitamin B1 in their body, so thiamine must be supplemented in their food on a daily basis.
Thiamine is needed to process carbohydrates and get the nutrients out of them. So, a diet that contains a lot of carbohydrates (such as grains or starchy vegetables) needs more thiamine, than a meat diet. Sadly, a carbohydrate rich diet that is deficient in thiamine is a double whammy for cats.
Foods high in thiamine
Thiamine is found naturally in food products such as yeast, whole grains, vegetables and legumes. It is also found in organ and muscle meats such as 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 that you feed your cat organ meat as well as muscle meat.
To illustrate, let’s look at the amount of thiamine (mgs) per ounce (28.35 grams) in raw chicken meat and organs.
- Chicken liver – 0.086 mg
- Chicken heart – 0.043 mg
- Chicken thigh – 0.022 mg
- Chicken breast – 0.019 mg
Pork, duck and salmon are high and good sources of thiamine. 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 rotation of meals but should not be fed every day.
Thiamine deficiency symptoms in cats
The earliest warning signs of thiamine deficiency in cats may be gastro-intestinal symptoms, such as a decreased appetite, salivation, vomiting, diarrhoea or weight loss.
However, as the problem intensifies, the nervous system becomes involved. Typical clinical signs for thiamine defiency include neurological symptoms such as:
- stumbling
- circling
- walking as if drunk
- low head carriage, as if the head is too heavy to lift
- extremely high head carriage, as if pulled back by an invisible string
- head tremors
- a head tilt
- eyes flicking from side to side in an uncontrolled way
- dilated pupils
- seizures
- coma.
What causes thiamine deficiency
The most common causes of thiamine deficiency in cats are either health or diet related.
Gastrointestinal diseases
Health problems such as inflammatory bowel disease or stomach cancer, cause the gut wall to thicken which can interfere with the absorption of thiamine present in the diet.
Passing a lot of urine
Cats that drink a lot, because of diabetes or kidney disease, excrete a large volume of urine. This has the effect of washing vitamin B1 out of their system, with the potential to create thiamine deficiency.
Raw fish diets
Certain types of fish, and especially shellfish when fed raw, contain an enzyme called thiaminase. This enzyme actively destroys vitamin B1 and leads to dietary deficiency in thiamine. This only occurs with raw fish, as the thiaminase is destroyed by cooking. Thiaminase is not present in salmon or cod which are the most common fish ingredients in commercial canned cat food, although it is present in tuna.
Meat only diets
Because muscle meat is typically low in thiamine, it is possible to accidentally cause thiamine deficiency in your cat, if you feed raw meat to the exclusion of everything else.
We cannot stress this enough. If you are feeding a homemade raw meat diet or cooked cat food diet, you MUST ensure that 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 some great balanced pre-mix meal completers available including EZComplete.
Manufacturing problems and pet food recalls
You’d think that adding thiamine to the raw ingredients during manufacture would be safe enough. However, thiamine can be accidentally destroyed during the pet food manufacturing processes, for example when exposed to high heat.
Treatment with high amounts of sulphur dioxide, which acts as a food preservative, also breaks down thiamine. Other factors such as adding thickening agents which change the pH (acidity) of the raw ingredients, can also damage the original vitamin B1 in meat products.
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
How your vet diagnoses thiamine deficiency
When a cat has neurological signs, your vet will draw up a differential diagnosis list of the problems that could cause the symptoms. Included on this list are infectious causes (toxoplasmosis), lead or heavy metal poisoning, inflammatory conditions (such as encephalitis or meningitis) and thiamine deficiency.
Your vet will run tests to confirm or rule out the various possibilities. If nothing conclusive is found, then thiamine levels can be measured with a blood test. However, many vets will choose to treat cats with a thiamine supplement and see if they start to get better. This is known as making a diagnosis by ‘response to treatment’ and may be quicker than waiting for results to come back.
Treating thiamine deficiency with supplements
The treatment for thiamine deficiency in cats is simply a matter of giving a vitamin supplement. This may be by intramuscular injection for 3 to 5 days, followed by a daily oral supplement and care given at home.
Thiamine supplementation is available as a tablet or syrup, and is available in general multivitamin products. The dose for a cat is: 5 to 30 mg of thiamine per cat per day, up to a maximum of 50 mg per cat per day.
As we’ve already mentioned, cats cannot store thiamine in their body. So, if you give your cat too much it should just be peed out in their urine. Even so, avoiding an overdose is a sensible idea so always follow the advice of your veterinary team.
