“Complete” plant-based dog foods lack nutrients, new research reveals

Despite being marketed as “complete” nutrition, plant-based dog foods sold in the UK do not fully meet nutritional guidelines, according to a new UK analysis. The researchers compared six veterinary foods, 19 meat options, and six plant-based products — none were nutritionally “complete.”

The study authors note that meat and plant-based foods had a similar nutritional composition, but iodine and B vitamins were lower in plant-based products. However, as these nutrients can easily be supplemented, the researchers say adopting a plant-based diet for dogs can provide nutritional adequacy regarding macro- and micronutrients. 

Although the majority of veterinary foods (66%) were designed to be lower in protein, the study reveals that they often have less-than-optimal essential amino acid composition. 

“Many of us assume that dogs need meat to stay healthy, but in fact, what they really need are the right nutrients,” says Rebecca Brociek, Ph.D. researcher in Companion Animal Nutrition at the University of Nottingham, UK. 

“Similar studies have been undertaken comparing plant-based dog foods in Brazil and Canada, and we wanted to compare those available in the UK.” 

“What I found was surprising — these foods stacked up more closely to meat-based diets than expected, with all showing some nutritional gaps. With more studies on plant-based pet foods emerging every year, I’m excited to help move this conversation forward.”

Plant-based dog food

As omnivores, dogs can derive nutrition from both meat and plants. The researchers note that a growing interest in a plant-based lifestyle among dog owners drives demand to feed their pets a similar diet. 

Although previous research links such diets to micronutrient deficiencies, the study authors say there has been limited research on the completeness of plant-based dog diets. 

According to the UK’s Food Standards Agency, products must include all the macro- and micronutrients a dog needs to be labeled as “complete” dog food. 

Unless manufacturers reformulate their products, the researchers recommend dog owners to supplement their pets with iodine and B vitamins.For the study published in PLOS One, the researchers analyzed the nutrient content of 31 dry dog foods commercially sold in the UK and labeled as “complete.” The veterinary foods included in the study were all designed for dogs with kidney conditions and were low in protein. 

The plant-based products typically did not meet the European Pet Food Industry Federation (FEDIAF) guidelines for iodine and B vitamins in adult dogs. 

The researchers suggest that either pet food manufacturers reformulate their products to include these nutrients or dog owners provide them to their pets as supplements. 

Meanwhile, the study reveals that none of the foods met FEDIAF standards for all nutrients for adult dogs. Out of the 31 products tested, all met guidelines for vitamin D levels, but only 17 contained sufficient amino acids, five met guidelines for minerals, and only four met B vitamin levels. 

The study’s authors say future research could help address some of its limitations, such as considering the nutritional requirements for younger dogs that are still developing. Moreover, new research could account for biochemistry in the dogs’ digestive system that may impact nutrient levels absorbed from a complete food. 

Pet nutrition market

The market for pet nutrition products is growing as consumers seek products to increase their pets’ longevity and overall health. There is also an increasing interest in natural, sustainable, and plant-based offerings. 

Pet nutrition also emerged as a key focus at this year’s Vitafoods Europe trade show, reflecting a growing trend of pet “humanization,” where consumers treat their companion animals as integral members of their family, which should be served food and supplements that are fit for human consumption. 

Nutrition companies are also increasingly active in the space. Recently, research backed ADM’s microbiome-boosting and dental plaque-fighting postbiotic for dogs, while Nutrileads unveiled that its Benicaros prebiotic can boost gut health across all dog breeds.