In a complete diet, besides water; proteins, fats, carbohydrates, minerals, and vitamins are five key required nutrients. Energy is derived from carbohydrates, fats, and proteins for growth, body temperature regulation, feed digestion, and activity. Carbohydrates are an immediate source of energy for activities and are stored in muscles and the liver as glycogen. The functioning of the brain, nervous system, and other body functions like metabolism depends on it. Of the 2 types of carbohydrates, dietary energy is obtained from digestible carbohydrates viz., sugars and starches. The dietary fiber is obtained from indigestible carbohydrates which are good for gut motility and stool quality. Dietary fibers can also be adjusted to manage weight as they have low calories but give the feeling of satiety.  Carbohydrate ingredients are mainly of plant origins like potatoes, wheat, rice, peas, barley, and corn. For dietary fiber, soybean hulls, wheat bran, and dried beet pulp are used. These carbohydrate sources have good digestibility, the only exception is to lactose as animal lacks lactase in the body. Dietary fats, a source of fatty acids, are crucial as they help in the transport and storage of fat-soluble vitamins. Fats improve the texture and palatability of food. Compared to carbohydrates and proteins, fats provide 2.5 times more energy. Therefore, fats are more important for active animals. However, care should be taken as an excess of it makes your pet obese. Fat ingredients can be of vegetable or animal origin. Vegetable oils, flaxseed, fish, and shellfish provide omega-3 and omega-6 families of FA necessary for cell membranes, reducing inflammation, repairing tissue, and steroidal hormone production. Fats & oils are also important for a glossy coat, reproduction, and kidney functions. Proteins are required for the building of muscles, blood, immune system, bones, organs, hair, and nails. It is of utmost importance that the dog eats the right amount of protein, gets digested and absorbed. Any excess consumption won’t be of any good as it will get excreted. Amino acids are building blocks of proteins and 10 essential AAs are required in a dog’s diet. Dog foods contain protein from vegetables as well as animal origins like rice, peas, soybeans, eggs, fish, pork, beef, and poultry. Macro-minerals required are Ca, P, K, Na, Cl & Mg, while Fe, Cu, and Se are micro-minerals required in trace amounts. Vitamins are required in small amounts but are crucial for many body functions. Dogs cannot make all vitamins needed so make them available with diet.

The most commonly used food ingredients in dog food are meat, vegetables, cereal, and dairy products. Meat and animal derivatives are good sources of protein, fatty acids, iron, and a few of the B complex vitamins. They are palatable and highly digestible. Meat sources are lamb, beef, poultry, pork, and fish. Fish provides high-quality protein. Their muscles contain iodine. Their bones are ground to make it a pet food and is the source of Calcium and Phosphorus. Oily flesh of fish has fat-soluble vitamins like vitamin A & D, and also has omega-3 fatty acids. Fishes are mainly of 2 types. Oily fish includes herring, mackerel, tuna, salmon, trout, and sardines, while the whitefish group includes cod, whiting, haddock, and sole. Dairy products and eggs contain high-quality and easily digestible protein. They also provide Ca and a number of vitamins. Cheese & milk products are often used in dog foods. Vegetables are used as a source of fiber, minerals & Soybean is mostly used for energy, protein, omega 6, vitamin B, minerals & fiber sources. Cereals are a good carbohydrate source for dogs along with some proportion of protein and vitamins like thiamine and niacin. Maize, wheat, corn, barley, and sorghum are mainly used cereals. Fibers from rice bran, beet pulp have additional health benefits on a dog’s digestive tract.

Now with the knowledge of what & why nutrients are required to the sources of these nutrients, here are feeding practices common among dog owners. For some owners, homemade diets are an appealing idea. They prefer homemade raw diet feeding to their dogs. Raw feeding means providing a diet made up of offal, raw meat & bone, mixed with some vegetable fruits, seeds, oils, and nuts. Owners feel that they can have better control on a diet when homemade. They want to provide natural food to dogs than relying on food companies that have artificial products in formula foods. However, it might sound appealing but the truth is, in a homemade diet a fundamental concern rises that whether all required nutrients are provided in the right amount and proportions for healthy body function or not. In a study, out of 95 raw food analyzed ration samples, 60% found to have major dietary imbalances while the rest 40% with minor imbalances or we can say balanced. A lot of recipes are available over the internet for homemade food. In a study at California University, 200 different recipes from websites, pet care books, and veterinary textbooks were analyzed. The findings were surprising, as 84% of recipes were deficient in multiple nutrients while 95% were lacking at least a single essential nutrient. Only 9 recipes met NRC’s minimum requirements. It is because most recipes are crudely balanced by computers but don’t act fruitful in reality. Normally, dogs require at least 37 essential nutrients that must be present in their diet. With this article, we will provide any dog owner to have general guidelines to formulate nutritionally appropriate & customized recipes for canine cuisine. For that, the initial thing is to have knowledge about the body requirements of these nutrients by dogs. For that, we have NRC values given in Tables 1, & 2. You should keep these required values in mind while formulating a ration. 

Table 1: Daily Maintenance Energy Requirements (MER) for Dogs

Table 2:  Nutrient Requirements (Maintenance) for Adult dogs and Puppies after Weaning

The selection of ingredients for homemade diet is totally based upon the owner. There is a need to have a blend of different kinds of stuff, otherwise, a homemade diet, made up of a single item, will remain inadequate and cause nutritional deficiency diseases. For stance you are exclusively feeding your dog with rice or hamburger diets, it will cause calcium deficiency and secondary hyperthyroidism. Exclusive feeding of the liver causes vitamin A toxicity. Therefore, always take different ingredients and which must come from safe and reliable sources, ensuring food safety. The purchased stuff/products must be in good condition.

Prefer to meet 60-70% of protein from the animal sources because at the same time they also met more calorie requirements than plant sources. In summer, high protein diets are often rejected. Therefore, in summer lower the protein content and can also opt for a totally vegetable-based diet. Dogs, by nature, are omnivores and can thrive on vegetarian diets. They adapt well to a nutritionally complete homemade vegetarian diet that is purely organic & natural. With vegetarian diets salmonella, listeria & other zoonotic pathogens, contamination can be avoided.

The growing body of a pet will be evidence that a dog can survive and indeed thrive on balanced vegetarian diets. In an experiment, vegan dogs are seen to have decreased ectoparasites, food intolerance reactions, reduced obesity, allergy control, arthritis regression, and improved coat. The pumpkin, spinach, beetroot, and potato as ingredients can also be used. However, such diets need serious attention on the availability of all nutrients that are normally obtained from animal sources like arginine, methionine, lysine, taurine, tryptophan, iron, zinc, calcium, vitamin A and some vitamin from the B complex group. These diets can be further improved by the use of dietary supplements to fulfill the requirements of essential minerals and vitamins.

For active dogs, a careful balance of phosphorus, calcium, and vitamin D is required for strong bones and healthy teeth. Additives like flavors, antioxidants, preservatives, and colors can be used too. Preservatives either natural or artificial can be used to prevent food spoilage, maintain high quality, and improve food palatability. Antioxidants like Vitamin E, C, and selenium play a vital role in long-term health and well-being of dog as they neutralize free radicals in food and body.

Certain human food ingredients contain substances that are toxic for pets. Therefore, care must be taken while selecting human food items as an ingredient like garlic, onions, chocolate, xylitol-sweetened foods, grapes, avocados, and some nuts. Grapes have some unknown toxic substance that causes kidney damage. Chocolate has theobromine and little caffeine that are methylxanthines. These are very slowly metabolized and cause GI signs of toxicity progressing to polyuria, arrhythmias & seizures to death. Garlic & onions have thiosulfate that induces oxidative damage to dog’s RBCs, causing anemia. Onions prove to be more toxic than garlic. Guatemalan avocados have “persin” substances that cause dyspnea, pleural & pericardial effusion, and pulmonary edema. Xylitol-containing foods induce liver damage. Macadamia nuts cause potential toxicity to dogs causing vomiting, ataxia, muscle tremors, depression & tachycardia.

Besides homemade diet, commercially available foods is another popular way of feeding. Most owners feel it an easy way of feeding and you can also introduce commercial foods if there is any food rejection or GIT upset with homemade recipes. With commercially available foods, the owner can easily select food that reflects its own taste, pet’s required nutrition, and owner’s budget. Today the industry is moving ahead of demands from customers as in the pet food industry the field of nutrition is moving very fast and its offers are constantly evolving. Today foods are available as dry, wet, semi-moist, jelly foods, treats, and snacks, canned and raw foods. The owners’ considerations for any quality prepared food are based upon circumstances like pet’s activity level, life stage, therefore, foods are available for each stage of life (4-14wk puppies; >14 wks puppies and adult dogs). These pet food manufacturing industries usually follow FEDIAF values that are NRC reviewed values for formulating a diet. It provides the guidelines for feeding recommendations that are approximate values per day and must be adapted to suit your pets’ requirements and external influences. Given below in table 4 are the analytical nutritional percentage available in the majority of commercial products. It is also advised to owners to look at the statement about nutritional completeness on packaging themselves, as there is no specific right way to select food as long as their nutritional demands are fulfilled. Followings are the information collected from local market regarding available products and their chemical composition (as printed on the product).