Thiamine (Vitamin B1)

A thiamine deficiency can show up as an unsteady walk, a downward bending of the neck and seizures.

Thiamine is vitamin B1, and cats need it in their diet. FDA has posted cat food recalls for low thiamine levels, and one notice lists early signs of deficiency such as decreased appetite and vomiting, with neurological signs in advanced cases. Complete cat foods add thiamine to meet nutrient targets. A cat that shows these signs, or has a medical condition, needs a veterinarian.

Source: fda.gov

Thiamine is added because cats need a steady supply of vitamin B1 and it is easily lost. Heat during cooking and canning breaks thiamine down, so manufacturers add extra to cover processing losses. On a label it often appears as thiamine mononitrate or thiamine hydrochloride.

Some raw fish can. The Merck Veterinary Manual says thiaminases, enzymes that break down thiamine, are found in raw freshwater fish and clams, and that cooking destroys them. Feeding large amounts of raw fish that contain thiaminase can lead to thiamine deficiency in cats. Commercial foods are cooked, which inactivates these enzymes.

Source: merckvetmanual.com

Thiamine mononitrate is a stable salt form of vitamin B1 that holds up well in dry foods. It is one of the two common forms added to pet foods; the other is thiamine hydrochloride. Both provide the same vitamin to the cat once the food is digested.

Pettings gives thiamine 4 out of 5 and lists it as a vitamin. It appears on 149 of the 149 dry cat foods we list. It is on every dry food in our list, which matches its status as a vitamin cats must get from food. Each food's page shows how it scores overall.