Page 257 - Small Animal Clinical Nutrition 5th Edition

262 Small Animal Clinical Nutrition

VetBooks.ir Box 13-3. Nutritional Factors of Concern reproducing dogs have varied from 85 kcal (355 kJ)
0.75
to more than 220 kcal (920 kJ) ME/BW
0.75
ME/BW
kg
kg
for Homemade Foods Intended for Adult (Zentek and Meyer, 1992; Männer et al, 1987; Heusner, 1991).
Dogs. This range may confuse dog owners, but it is not surprising
considering that breed, neuter status, age, daily activity, envi-
In addition to the key nutritional factors for commercial foods for ronmental temperature and insulative characteristics of the
adult dogs (See Key Nutritional Factors discussion.), calcium is integument markedly influence the DER of a particular dog
also a nutritional factor of concern for homemade foods for adult (Rainbird and Kienzle, 1990; Kienzle and Rainbird, 1991;
dogs.
Commercial foods may contain inadequate, adequate and Männer, 1990, 1991; Meyer, 1983; NRC, 2006; Gesellschaft,
sometimes excessive amounts of calcium and/or phosphorus 1989; Burger, 1994; Finke, 1991). Graphically, the DER for a
and; therefore, should not be supplemented. However, calcium population of dogs results in a bell-shaped curve; therefore, the
is often deficient and phosphorus may be excessive in home- energy intake of individual dogs may vary by about 50% above
made foods, especially when most of the diet comes from meat or below the average requirements, even within the same age
and leftovers from the table (Table 12-5). Existing commercial group (Chapter 1). The RER, however, is not markedly influ-
multiple vitamin-mineral mixes (powders, tablets, etc.) are sel- enced by these factors, and is similar for all dogs, independent
dom designed to correct imbalances encountered in homemade of breed or age. RER is approximately 70 kcal (293
foods. When formulating homemade foods, it is better to correct kJ)/BW 0.75 (NRC, 2006; Kleiber, 1975) (Chapter 1). A sim-
kg
calcium-phosphorus imbalances by adding mineral sources ple linear formula can also be used to estimate RER for dogs
such as calcium carbonate or dicalcium phosphate, both of weighing more than two kg: RER is approximately (30 x
which are usually available from drug stores (Chapter 10). kcal
BW ) + 70 (Lewis et al, 1987). To convert from kcal to kJ,
kg
multiply kcal by 4.184.Table 5-2 provides RER values for dogs
with body weights from 1.5 to 70 kg.
Because DER is the sum of RER plus all the above influ-
Water ences, it is better to use RER as the basis for calculating energy
Water accounts for approximately 56% of an adult dog’s body requirements of adult dogs and to assign different multipliers to
weight (73% of lean body mass) (Stadtfeld, 1978). The body account for differences in activity, age and environmental influ-
has a limited capacity to store water, and although healthy dogs ences. When assigning multipliers to RER, it is important to
can replenish a water deficit of up to 8% of body weight in a account for neuter status because this variable can be an impor-
few minutes (Anderson, 1982), water deprivation will result in tant factor in determining DER of household dogs. Neutered
death more quickly than withholding any other nutrient dogs may have a lower DER than intact counterparts. Surveys
(NRC, 1985).Therefore, it can be argued that water is the most have shown that the prevalence of obesity increases progressive-
important nutrient. ly and peaks in middle-aged dogs (Armstrong and Lund, 1996;
Total water intake (i.e., drinking and water from food) is Kronfeld et al, 1991). Thus, prevention of obesity should be an
influenced by several factors such as environment, physiologic important goal of feeding programs for young adult dogs.
state, activity, disease processes and food composition. Total Animals benefit more from an appropriate weight-mainte-
water intake increases almost linearly with increasing salt levels nance program than treatment for obesity (Chapter 27).
in food (Anderson, 1982; Burger et al, 1980). Switching from a Three groups of adult dogs can be distinguished based on
moist to a dry food and vice versa markedly affects the amount DER: 1) one to two years old, 2) three to seven years old and
of water taken with the food; however, dogs compensate well 3) more than seven years old (Table 13-2) (Rainbird and
for this difference by changing the quantity of water they drink, Kienzle, 1990; Kienzle and Rainbird, 1991; Finke, 1991, 1994).
thus keeping their total daily water intake constant (Burger et The differences in DER probably reflect an age-related
al, 1980). Generally, dogs self-regulate water intake according decrease in activity and lean body mass.
to physiologic need. Healthy adult dogs need roughly the Most pet dogs are minimally active and may have a DER
equivalent of their energy requirement in kcal metabolizable that approaches their RER. Such dogs fed caloric intakes rec-
energy (ME)/day, expressed in ml/day (Lewis et al, 1987). ommended for maintenance (1.6 x RER) will be overfed and
Dogs should be offered free access to water at rest and before, are likely to become overweight. A recommendation of 1.2 to
during and after exercise (NRC, 2006). During warm weather, 1.4 x RER (85 to 98 kcal [355 to 410 kJ] ME/BW kg 0.75 /day) is
enough water should be available to compensate for evapora- a good starting point for feeding sedentary dogs (Männer,
tion by panting (Anderson, 1982) Box 13-2. 1990, 1991; Männer et al, 1987; Heusner, 1991; NRC, 2006).
A good starting point for estimating the DER of more active
Energy adult dogs would be 1.6 x RER (115 kcal [480 kJ]
Domestic canids are the most diverse mammalian species in ME/BW kg 0.75 ). Such dogs between two and seven years of age
body weight and size. Therefore, energy requirements are not would probably have a DER between 1.4 to 1.9 x RER (100 to
linearly correlated with kg body weight, but are more closely 130 kcal [420 to 550 kJ] ME/BW kg 0.75 ) with the higher num-
related to metabolic weight (BW kg 0.75 ) (Meyer, 1986; NRC, ber used in the lower age group and the lower number applied
2006). DER recommendations of adult, non-athletic, non- to the higher age group (Table 13-2). All initial estimates of