Can a vegan or vegetarian diet be beneficial for dogs and cats? Barbara Tonini, a veterinary doctor specialising in animal nutrition, shares her views on the subject.
Can our dog – and our feline friend – do without a meat-based diet and become, even if only for a while, a perfect "vegan"? The issues inherent in the use of meat in the diets of dogs and cats have often been highlighted, particularly with regard to the use of antibiotics in intensive farming and the association between a meat-based diet and the onset of tumours. We discussed this "provocation" on the subject of animal nutrition with Dr Barbara Tonini, a veterinary doctor specialising in the nutrition of dogs and cats.
"Unlike humans, who are omnivores, animals are carnivores, and their anatomical characteristics are a clear demonstration of this. One need only think of their highly developed sensory organs for locating prey, the musculoskeletal system suited to catching it, the sharp teeth for tearing tissue, and the shorter gastrointestinal tract with digestive enzymes and an intestinal microbial population that differs from that of herbivores, which indeed require longer digestion times."
But the long coexistence of these animals with humans has brought about a profound transformation in the behaviour and diet of our animal companions. "Over time, the domestic dog has developed a good digestive capacity when it comes to starches," Dr Tonini continues. "Over the years, the household pet has often had to make do with what was left over from meals, and meat rarely ended up in its bowl. One need only ask our grandparents to understand how, until not so long ago, meat was a precious commodity, often reserved only occasionally even for their own children or grandchildren."
Could dogs, then, follow a diet free from animal protein? "It is very important to clarify that all animal species, humans included, require specific nutrients rather than specific ingredients," answers Dr Tonini. "Attention should therefore be focused above all on meeting the daily requirements for certain nutrients, such as amino acids (taurine, methionine, lysine, tryptophan), vitamins (the B group, D3, A and E), minerals (calcium, phosphorus, zinc) and certain fats (linoleic acid, EPA, DHA): all nutrients whose deficiency can trigger or contribute to the development of disease. An exclusively plant-based diet, in addition to having lower digestibility for dogs, may contain anti-nutritional factors such as phytates, for example, which reduce the absorption of important minerals such as calcium, magnesium and zinc."
So, at this point, can we forget about a vegan diet for our dogs? Barbara Tonini clarifies: "I can say that it is possible to give dogs a vegetarian or even vegan diet, provided it is adequately balanced and supplemented, so that it can meet the nutritional requirements of our four-legged companions. But this only ever applies to adult animals in perfect health, since puppies and elderly dogs require more rigorous nutritional management owing to their reduced ability to adapt to excesses or deficiencies of certain nutrients." The input of a veterinary nutritionist becomes, in this context, essential. It is the specialist, in fact, who will choose the ideal diet for our dog, one capable of providing a perfect balance of essential nutritional intake. Care should be taken, however, not to apply the same reasoning to the household cat. "The cat is a strict carnivore," explains the expert, "which also uses proteins for energy purposes, and when diets with a reduced protein content or low biological value are given, it is unable to 'conserve' the limited availability of essential amino acids for protein synthesis."
Let us draw conclusions, then, from our "provocation" on the subject of four-legged diets. It appears that a vegetarian or vegan diet can be reserved only for adult dogs in excellent health, and always exclusively with a diet specifically formulated by an expert. A do-it-yourself approach in these cases could lead to the onset of diseases or nutritional problems of some significance. There are, however, also cases in which meat could be excluded from a dog's diet – indeed, eliminating it would be obligatory. "We are talking about certain illnesses," adds Dr Tonini, "such as hepatic encephalopathy, or urate urolithiasis, in which the intake of animal proteins in the daily diet must be carefully monitored and sometimes avoided altogether. In this case too, however, these are conditions in which veterinary input is essential to establish precisely the nutrient requirements and supplements to be administered to the little patient."
The fact remains that the ethical choice of a vegetarian or vegan diet for our four-legged friends is a matter to be carefully debated with the attending vet and the nutritionist specialist. Respect for animals, in fact, also involves a careful examination of their specific characteristics, including – and above all – their dietary ones.