Carrageenan (E 407) is a natural extract of seaweed that has been used as a food additive for hundreds of years. It is employed very widely in both the human and pet food industries as a thickener, stabiliser and texturiser. In human food, carrageenan can be found in all sorts of foods from soy milk and yogurt to prepared meals and deli meats. In pet food, carrageenan is most often added in very small amounts to paté and loaf type wet foods to give them their characteristic firm consistency.
Which foods contain carrageenan?
As we mentioned above, carrageenan is primarily used in paté and loaf type wet pet foods. Unfortunately, since it is a technological additive and only needs to be added in very small amounts, it does not need to be declared by the manufacturer.
If you would like to find out whether your wet pet food contains carrageenan or not, you can either look for the phrases 'stabilised with carrageenan' or 'guaranteed carrageenan free by the manufacturer' on the product's review page here on AADF or, if you don't see them, you'll have to contact the manufacturer directly. The trouble is, since many wet food manufacturers outsource their production to third-party factories, their information might not be completely accurate. You could ask the manufacturer to check with their factory but since most factories source their ingredients from dozens if not hundreds of suppliers, any of which could add carrageenan to their mixes, even the factory might not know for sure.
To be 100% certain, you therefore need to ask the manufacturer to get confirmation from both the factory and the ingredient suppliers, which is a tall order.
Despite its widespread use and long heritage, carrageenan has attracted considerable criticism from certain quarters of the scientific community.
A number of studies  have linked food grade carrageenan (also known as un-degraded carrageenan or just CGN) to gastrointestinal inflammation as well as higher rates of intestinal lesions, ulcerations, and even tumours. Degraded carrageenan (sometimes called poligeenan or dCGN), though, is far more potent. It is a known carcinogen and is routinely used to induce inflammation in lab animals so that scientists can test anti-inflammation drugs. While degraded carrageenan is not permitted in pet food, there is concern that some food grade carrageenan may be contaminated with dCGN  and also that the acid environment of the stomach may degrade food-grade carrageenan to form dCGN .
HOWEVER, for every study suggesting carrageenan could be problematic, there is another indicating that it is perfectly safe. Although many of the more pro-carrageenan studies are funded by and in many cases directly carried but by carrageenan producers (Celtic Colloids, FMC) or their affiliates (Toxpertise, Iontox), they are still subject to peer review and not without merit. In particular, a comprehensive review carried out in 2014 concluded that no studies to date had adequately demonstrated any carcinogenic, tumour promoter, genotoxic, developmental or reproductive effects from consuming food grade carrageenan .
Most significantly, in 2018 the European Food Safety Authority carried out its own investigation into carrageenan and found no adverse effects from carrageenan in rats all the way up to 7,500 mg/kg of body weight per day, which is WAY more than is found in pet foods and was the highest dose tested . They did, however, express some uncertainties over the general lack of reliable information on the additive's effects and suggested more work was necessary before they could be 100% sure of its safety.
Carrageenan is certainly not the worst additive in pet food and for most dogs, the very small amount used is not likely to cause any upsets at all but we do still think caution is warranted. If your dog has a history of digestive upsets, it may well be best to look for a food that is free from carrageenan and other similarly controversial ingredients. Changing the diet up every so often would also help to limit the chances of carrageenan or any associated issues from building up in the dog's system over time.
Review of Harmful Gastrointestinal Effects of Carrageenan in Animal Experiments. Tobacman JK. Environmental Health Perspectives 109(10): 983-994. 2001. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1242073/
Exposure to common food additive carrageenan leads to reduced sulfatase activity and increase in sulfated glycosaminoglycans in human epithelial cells. Yang B, Bhattacharyya S, Linhardt R and Tobacman JK. Biochimie 94(6): 1309-16. 2012. https://www.ncbi.nlm.nih.gov/pubmed/22410212
Exposure to the common food additive carrageenan leads to glucose intolerance, insulin resistance and inhibition of insulin signalling in HepG2 cells and C57BL/6J mice. Bhattacharyya S, O-Sullivan I, Katyal S, Unterman T and Tobacman JK. Diabetologia 55(1): 194-203. 2012. https://www.ncbi.nlm.nih.gov/pubmed/22011715
Molecular weight distribution of carrageenans studied by a combined gel permeation/inductively coupled plasma (GPC/ICP) method. Yoshitaka Uno, Toshio Omoto, Yasunori Goto. Food Additives & Contaminants. 2010. https://www.tandfonline.com/doi/abs/10.1080/02652030117235
Food additive carrageenan: Part I: A critical review of carrageenan in vitro studies, potential pitfalls, and implications for human health and safety. McKim JM. Critical Reviews in Toxicology 44(3): 211-43. 2014. https://www.ncbi.nlm.nih.gov/pubmed/24456237
Food additive carrageenan: Part II: A critical review of carrageenan in vivo safety studies. Weiner ML. Critical Reviews in Toxicology 44(3): 244-69. 2014. https://www.ncbi.nlm.nih.gov/pubmed/24467586
Re?evaluation of carrageenan (E 407) and processed Eucheuma seaweed (E 407a) as food additives. EFSA Panel on Food Additives and Nutrient Sources added to Food (ANS). EFSA Journal. 2018. https://efsa.onlinelibrary.wiley.com/doi/full/10.2903/j.efsa.2018.5238
Find foods containing Carrageenan See the full Ingredient Glossary