Nutritional adequacy of vegetarian diets

Source: E. Kienzle and R. Engelhard. A field study on the nutrition of vegetarian dogs and cats in Europe. From Proceedings of Sixth Workshop in Pet Food Labeling and Regulations. p. 139

Recently, dog and cat owners have shown increasing interest in feeding their pets a vegetarian diet. This field study presents a survey of the primary reasons for choosing a vegetarian diet and an outline of the most frequent nutritional imbalances found in these diets.

The survey consisted of personal interviews. Owners were asked to fill out a questionnaire to provide a detailed account of their pet's diet and medical history and to present their dogs and cats for clinical examination.

If possible a blood sample was drawn. Energy and nutrient intake of the animals were calculated and compared with requirements. Additionally, twelve prepared complete vegetarian dog foods were investigated.

A total of eighty-six dogs were investigated in Germany, Switzerland and Belgium and applications continued to arrive after the survey was finished. By contrast, only eight cats were found which currently were fed a vegetarian diet.
With few exceptions, the survey's participants were also vegetarians who believed that animals should not be killed in order to provide meat and/or that meat production was carried out in a way which was cruel to the animals and detrimental to the health of consumers.
The protein intake was inadequate for over half of the dogs. Nutritional errors typical of all homemade diets also occurred in the vegetarian diets.

The calcium requirements were not met in 62% of the dogs' diets, likewise for phosphorus, which was below standard for roughly half of the dogs. This resulted in an unbalanced Ca/P ratio.

In addition, 73% of the dogs had an insufficient intake of sodium. In many cases, the supply of trace elements was inadequate. A high number of the plasma samples also showed insufficient amounts of iron, copper, zinc and iodine. Of the vitamin contents calculated, vitamin D was most often below recommendations.

Here also, a reduced plasma content of 25-OH-vitamin D was common. Fifty-six percent of the dogs showed a vitamin B12 intake below recommendations. Despite the fact that some of the diets were unbalanced, no clinical problems were found in the adult dogs.

The protein intake of the cats was not far below the requirements, although the amount of S-containing amino acids was frequently inadequate. None of the cats in the study were provided with enough taurine although products containing taurine were used.

Similar deficiencies to those of the dogs in minerals and trace elements, as well as vitamin D and B12 were found in the cats' diets. Vitamin A intake was deficient in all cases, and in all but two cases, cats had insufficient amounts of arachadonic acid. One cat showed symptoms of retinal atrophy and two displayed reduced frequency of estrus.

The mineral and vitamin content of the prepared vegetarian petfoods frequently did not provide a balanced diet for a dog's nutritional needs. Only two of the twelve products that were analyzed can be recommended without reservation.

Source: E. Kienzle and R. Engelhard. A field study on the nutrition of vegetarian dogs and cats in Europe. From Proceedings of Sixth Workshop in Pet Food Labeling and Regulations. p. 139.

Any information above is given in good faith by our Nutritional advisors and may not necessarily reflect the opinion of Burns Pet Nutrition. The advice of Burns Pet Nutrition or a qualified veterinary surgeon should always be sought before changes are made to the diet in the nutritional management of health problems. Burns is a food and not a medicine.