To cook or not to cook? Many people now opt for a home-prepared diet for their four-legged friends. But there is one particular thing to bear in mind when choosing this type of feeding: cooking the ingredients that will go into the bowl, unless you opt for a diet based on raw ingredients. Getting it wrong when putting meat, rice or vegetables in the pot can cause nutritional errors that affect health and may, over time, lead to some fairly significant problems. We discussed this with an expert: Dr Barbara Tonini, veterinary surgeon, who taught us the secrets to cooking food for dogs and cats.

Why cooking food matters in a four-legged diet

Food prepared for our animal friends must be cooked in a way that avoids nutritional waste. "Raw feeding has an ever-growing number of supporters among dog and cat owners, and the axiom 'eating raw means eating healthily' has become a true lifestyle for many. However, this is not always the case. And sometimes raw foods can cause problems for pets. Let us therefore look more closely at this aspect, also because cooking should not be demonised in a four-legged diet," explains Dr Tonini.

First and foremost, cooking food is a matter of hygiene. It performs a very important function: eliminating pathogenic microorganisms (bacteria, viruses and parasites). And the risks arising from microbiological contamination are absolutely not to be taken lightly. Infections from salmonella or Aujeszky's disease virus, though infrequent, can have fatal consequences for our animals.

"Cooking also increases the digestibility of starches and legumes, and if we were to forgo it, we would also be giving up a good share of calories and fibre. Not to mention the deactivation of certain toxic substances such as solanine in potatoes and avidin found in raw egg white," the expert continues. Lastly, cooking food also increases palatability. A somewhat fussy dog or cat – and in cats this is often an issue – will have fewer objections to the usual bowl of home-prepared food.

A few caveats

Nutrient losses during cooking are undeniable and can occur through two processes: in some cases, molecules will migrate out of the food (they are lost in the cooking liquid but remain intact), while in others they are denatured by heat and rendered unusable by the body. The most heat-sensitive vitamins are those of the B group and vitamin C (which fortunately is not essential for dogs and cats, as they are able to synthesise it), while among amino acids some essential ones are lost, including lysine, tryptophan and taurine (an essential amino acid in cats).

"Giving the cooking liquid is certainly a useful habit, as some nutrients will be recovered that way. We must not forget, however, that adding a mineral/vitamin and taurine supplement (in cats) to the home-prepared diet is always indispensable, and therefore, despite the inevitable losses secondary to cooking, it is always possible in this way to provide a complete diet," adds Barbara Tonini.

The basic rules for cooking the main foods for our animals

Cooking meat for cats and dogs

Cooking meat for our pets requires care to ensure it is safe and nutritious. Generally, bacteria are found on the outer surface of meat and brief cooking may be sufficient to eliminate them. However, microbiological risks of a viral and parasitic nature must also be taken into account. Follow these steps to prepare meat safely for your cats and dogs:

1. Preparing the meat: choose good-quality meat, preferably from safe and monitored sources. Rinse the meat under running water to remove any surface contaminants.
2. Cutting the meat: cut the meat into small pieces to ensure even and rapid cooking.
3. Cooking the meat: heat a pan over a medium-high flame or preheat the oven to 180°C. Cook the pieces of meat until they have lost their pinkish colour on the inside.
4. Checking the temperature: use a kitchen thermometer to ensure the meat has reached the appropriate internal temperature: at least 75°C for pork, and fully cooked through for horse meat and fish.
5. Saving the stock: do not discard the cooking stock. Use it to improve the palatability of your animals' daily food, especially for vegetables.
6. Serving the meat: allow the meat to cool to room temperature before serving it to your animals. Make sure the pieces are of an appropriate size to be easily chewed and digested.

Specific tips:

1. Pork: it can transmit Aujeszky's disease virus, which causes a fatal illness in dogs and cats. The virus is killed at 100°C maintained for at least one minute.
2. Horse meat and fish: cooking through the full thickness is recommended to eliminate trichinella (horse) and anisakis (fish).
3. Beef: it is generally safe if cooked on the outside, but mince requires thorough cooking.
4. Poultry (chicken and turkey): brief external cooking is generally sufficient thanks to rigorous inspection controls.

Finally, it is worth remembering not to discard the cooking stock, both for the nutrients it contains (amino acids, fats, minerals) and because it helps increase the palatability of daily food, especially where vegetables are concerned, as these are always the least favoured by dogs and cats.

Vegetables

The vegetables commonly given to our dogs, such as carrots, courgettes, fennel and celery, can be served raw. It is indeed important to remember that when vegetables are not cooked, they retain a higher content of vitamins, fibre and minerals. A word of caution, however. In order to be properly digested, they must be chopped or, better still, blended. This also means they will mix more easily with other foods, making them more palatable. With cats, however, the situation is different: being animals with extremely fussy tastes, it is unlikely they will eat raw vegetables, so the advice is always to cook them and then blend them into a purée. The best cooking method? Steaming, which preserves the organoleptic properties because minerals and vitamins are not diluted in the cooking water.

Complex carbohydrates

As for complex carbohydrates — namely rice, pasta, potatoes or other cereals/pseudo-cereals (such as barley, spelt, quinoa, millet, etc.) — these should be well cooked to increase their digestibility. On the other hand, excessive cooking causes a loss of starches into the cooking water, thereby reducing the caloric content. So, in answer to the question: "How long should I cook the rice?", one should allow approximately 30 per cent more than the time indicated on the packet.