Nutrition and feeding are integral to good pet care as a correct diet can improve the quality of life, as well as longevity by preventing dietary related disease throughout the animals’ life stages. Correct diet can also aid in the management of diseases, such as feeding specially formulated diets to dogs with chronic kidney disease (Baldwin, et al., 2010). I will be looking into the dietary requirements of canines, and key nutritional changes through life stages.
Dogs require energy to sustain normal activities, this energy is gained from carbohydrates, proteins and fats. Animals have unique energy needs based on their life stage, health and activity levels (see Table 1) (Ackerman, 2016). They also need several other key nutrients for survival; Amino acids, fatty acids, vitamins, minerals and water (National Research Council, 2006). Water is one of the most important nutrients, with even small loses leading to clinical signs. The amount of water an animal should consume daily should be similar in millimeters to the daily energy intake in kilocalories (Ackerman, 2016). Carbohydrates and dietary fibre are the main sources of glucose in a dog’s diet, ass the glucose can be directly absorbed with no need to be broken down by enzymes (National Research Council, 2006).
Adult dogs require proteins and amino acids. Dietary proteins contains 10 essential amino acids that dogs cannot synthesize themselves. These allow for many biological activities and compounds to be formed (National Research Council, 2006). These also contribute to glucose conversion as they supply the carbon chains necessary for the interaction (Ackerman, 2016). High quality proteins are important as they will have the best balance of essential amino acids (National Research Council, 2006).
Fats and fatty acids can be found in animal fats, seed oils and plant matter; fats in the food can enhance the palatability of a dog’s food. These provide concentrated sources of energy (National Research Council, 2006). Essential fatty acids help keep a dog’s skin and coat healthy; these cannot be synthesized by the body and play important roles in carrying fat-soluble vitamins as well as roles in cell structure and function (Ackerman, 2016).
Dogs also require a range of vitamins (see Table 2) and minerals (see Table 3) in their diets which contribute to a variety of metabolic activities. They only need small amounts but if the balance is disturbed this can lead to deficiencies or excesses (detailed in Tables 2 and 3) (National Research Council, 2006).
Growing puppies who are weaned, usually at 4 weeks of age, can start to eat solid food. Up to 4 months of age they require 3 x RER and when they are 50%-80% of adult weight they require 2.5 x RER (Ackerman, 2016). When puppies start eating solids they will need little meals often, but it is important not to over feed as puppies can become obese very quickly. Musculoskeletal changes happen very rapidly in the first few months of growth and the skeletal system is particularly susceptible to physical and metabolic damage from under or over nutrition leading to skeletal deformities such as carpal flexor deformities, rapid growth can also contribute to hip dysplasia (Hemmings, 2016). Large and giant breeds are even more vulnerable to these damages (Hemmings, 2016) (Ackerman, 2016). Calcium and Phosphorus are key during growth, optimal levels should have a ratio of 1:1 and not be over supplemented. Over supplementation of calcium can lead to hypercalcaemia and hypophosphataemia (Hemmings, 2016). Copper and zinc are also important in in growth phase for osteoblast activity and protein synthesis; puppies require higher protein levels in growth for muscle growth (Hemmings, 2016).
Feeding a dog during pregnancy and lactation is important as it can contribute to the health of the bitch and her litter. A dog should only be considered for breeding if she is in a healthy state with a good body condition score (BCS) as an unhealthy dog may produce an unhealthy litter, have poor milk production or be unable to support themselves through the pregnancy (Ackerman, 2016). Gestation in the bitch lasts around 63 days, although most foetal growth and weight gain occurs in the final third of the pregnancy, as well as mammary and uterine tissue development. An increase of nutrients for the bitch should start from around 35 days into gestation. By 63 days they should be getting 60% more food intake than at mating (Ackerman, 2016). Lactation also relies on a healthy bitch and good nutrition in pregnancy and lactation after whelping. The nutrition requirements of the bitch during lactation are dependent on how much milk she needs to produce due to her litter size, examples of this can be seen in Table 1 (Ackerman, 2016). The bitches milk is very rich and can contain twice as much protein as cow’s milk to support the growth rate of puppies (Hemmings, 2016). When feeding a pregnant or lactating bitch, it is often advised that they are fed a complete puppy food to allow for the amounts of nutrition they need, they often require twice as much quality protein and fats in their diet (Hemmings, 2016).
Feeding geriatrics can be difficult, as dogs become senior at different ages dependent on their breed, larger breeds reaching seniority at around 5 years of age and smaller breeds at approximately 8 years (Ackerman, 2016). Age is not a disease, but it does bring physiological changes that increase a dog’s vulnerability to diseases and morbidity, and many disease process that affect older dogs may require nutritional management, such as endocrine disorders and renal diseases (Moyers, 2015). Geriatrics may benefit from increased fibre in their diet as well as higher protein level to help counteract muscle wasting (Moyers, 2015). Studies have also shown that older dogs benefit from decreased amounts of phosphorus in their diet as higher levels can make renal disease more severe, and the calcium to phosphorus ratio should be in the range from 1.1:1 to 1.8:1 (Moyers, 2015). Low fat diets are also recommended to prevent obesity in less active geriatrics, however, old dogs also tend to lose weight; they may benefit from increased energy content diets to improve protein efficiency (Moyers, 2015).
Canine nutrition varies throughout their life stages and can present owners with various challenges in meeting their needs. Key factors such as age and size can play roles in which key nutrients they need for good health and to meet their necessary daily energy requirement (DER). Having the correct macro and micro nutrients can allow for the correct function of physiological systems and aid in growth and disease management.