The caloric density of a diet must be provided by the pet food manufacturer and included on the label. In combination with information about the percentages of calories contributed by fat, carbohydrates, and protein, it can be used to determine the suitability of the food for pets of different ages.2<\/sup> The caloric density of a diet must be known to accurately estimate the appropriate feeding volume based on patient energy needs. <\/span><\/p>\n While caloric density is an important factor in choosing a particular diet for a patient, it should not be the only consideration. For example, a growing puppy\u2019s dietary needs are very different from those of an older, overweight dog or a canine athlete. Dietary recommendations for each patient should therefore be based on several factors, such as life stage, current body condition, and desired body condition, in addition to caloric density.1<\/sup> <\/span><\/p>\n The concept of energy balance is crucial to understanding how factors such as activity level and life stage affect the caloric intake needed for an individual animal to attain or maintain a healthy weight. Energy balance assumes that the number of calories being consumed is equivalent to the number of calories being expended. If a pet consumes fewer calories than it expends, the result is a negative energy balance. If the patient continues in a negative energy balance for a period of time, it will lose weight. A positive energy balance results when more calories are consumed than expended, resulting in weight gain. <\/span><\/p>\n Energy expenditure is affected by many variables. For example, pregnancy, lactation, growth, and work require tremendous amounts of energy to be safely and effectively completed. Intact pets also tend to require more calories than spayed or neutered pets. Geriatric, inactive, or overweight pets require fewer calories than younger, more active pets to ensure appropriate energy balance.<\/span><\/p>\n The first step in calculating the caloric intake needed by an individual patient is determining the patient\u2019s resting energy requirement (RER). RER is the amount of energy required for essential physiological functions such as digestion, respiration, and cardiac and brain activity.3<\/sup> However, RER alone does not account for any variation in growth, activity level, or environmental temperature. Therefore, a more accurate and patient-specific measure of a pet\u2019s energy requirement to achieve energy balance is the daily energy requirement (DER), which is calculated based on RER modified by a factor reflecting life stage and activity level.4<\/sup> DER factors for dogs and cats are listed in <\/span>TABLES 1 AND 2<\/b><\/span>.<\/span><\/p>\n Achievement and maintenance of a healthy body weight for patients can be a challenge, particularly for those that are ill and\/or hospitalized. Patients that are not feeling well enough to maintain their RER on their own need nutritional support to maintain caloric intake and reduce detrimental effects of negative energy balance and subsequent weight loss. The effects of inadequate nutrition can include decreased immune system and cellular function, poor drug metabolism and wound healing, loss of lean body mass, and organ dysfunction, all of which contribute to prolonged illness and\/or hospitalization.7<\/sup> Nutritional support for these pets is typically provided via feeding tube. <\/span><\/p>\n While breed is a factor in determining a healthy weight, it can be difficult to accurately estimate a patient\u2019s ideal weight based on breed alone, particularly since most pet dogs and cats are mixed breed. Body condition scoring (BCS) and muscle condition scoring (MCS) therefore play important roles in determining ideal body weight for individual animals. These scoring methods use a combination of visual assessment and physical palpation to evaluate body fat and muscle using the BCS and MCS, respectively. <\/span><\/p>\n In 2021, the American Animal Hospital Association standardized the 9-point BCS scale (<\/span>bit.ly\/3koJj0G<\/span><\/a>).8<\/sup> Ideal body condition falls in the center of the scale at 5; however, 4 may be an ideal score for giant-breed dogs. Values below 5 indicate that the patient is slightly underweight (3 to 4) to emaciated (1 to 2). Values above 5 indicate that the patient is overweight (6 to 7) to obese (8 to 9). Each point on the 9-point BCS scale represents approximately 10% body fat. Therefore, a BCS of 6\/9 equates to the patient being approximately 10% overweight, a BCS of 7\/9 estimates that the patient is 20% overweight, and so on. These same estimations can be applied to underweight patients.<\/span><\/p>\n Applying all of these concepts in the clinical setting can help quickly identify pets that could benefit from dietary adjustment as well as help create specific recommendations for owners. See \u201cCase Example: Sophie<\/b>\u201d for a step-by-step explanation of how to use BCS and calculate RER and DER in the clinic setting.<\/span><\/p>\n Based on her BCS, Sophie is approximately 20% underweight. Using this estimation, it can be assumed that at a healthy body condition, Sophie would weigh approximately 22.8 kg.<\/p>\n Diet History and Activity <\/strong> Maintaining energy balance requires consideration of not only caloric intake, but also energy expenditure. Sophie\u2019s owner is an avid hiker, and Sophie frequently joins a few times each week. Typical hikes are approximately 2 to 4\u00a0hours long with varying levels of incline through rocky and wooded areas.<\/p>\n Energy Calculations <\/strong> RER<\/strong> RER = 70(19)0.75<\/sup><\/p>\n RER = 70(9.1)<\/p>\n RER = 637 kcal\/day<\/p>\n DER<\/strong> Sophie\u2019s level of activity can be considered moderate work (TABLE 1<\/strong>).<\/p>\n The canine DER for moderate work is 3 (TABLE 1<\/strong>). Therefore, Sophie\u2019s DER is 637 \u00d7 3 = 1911 kcal\/day.<\/p>\n Feeding Plan <\/strong> Inclusion of 2 large Milk-Bones\/day (250 kcal\/day) into Sophie\u2019s diet would exceed the recommended limit of 10% daily calories from treats by providing 13% of her daily calories in treat form.<\/div><\/div>\n When an owner is asked what they feed their pet, the typical response is often limited to an estimated amount of a purchased diet. For example, an owner may report that they feed their cat a can of wet food in the morning and leave dry food out to be eaten ad lib, or they may feed their dog three-quarters of a cup of dry food twice daily. However, everything a pet consumes is part of its diet, including treats, medications and supplements, and table food.9<\/sup> On further questioning, the owner will likely reveal that they also feed their dog Milk-Bone Minis (5 to 10 daily, 5\u00a0kcal each), Beggin\u2019 Strips (1 daily, 35 kcal each), DentaStix for large dogs (about 3 per week, 84\u00a0kcal each) and peanut butter in a Kong (about 1\u00a0tablespoon 3 times per week, 90 kcal\/tablespoon). The dog also receives the occasional \u201cpuppuccino\u201d (about 1 each month, approximately 80 kcal) when in the car during a Starbucks stop and takes twice-daily medications in Pill Pockets (23 kcal each). On average, these extras add an additional 184 to 209 kcal per day! <\/span><\/p>\n When taking a dietary history from an owner, it is essential to question them about other calorie sources, such as treats, snacks used for medications or enrichment (e.g., peanut butter Kong, rawhides), and table food. Such items should account for a maximum of 10% of the pet\u2019s total daily calories when the DER is calculated.9<\/sup><\/span><\/p>\n Many tables and calculators are available for determining DER and RER for a given patient (<\/span>BOX 1<\/b><\/span>), though manually calculating these values is quite simple.<\/span><\/p>\n Pet Nutrition Alliance Calorie Calculator for Dogs<\/strong> petnutritionalliance.org\/dog.php<\/a> a<\/sup>The Pet Nutrition Alliance calculators are not designed for pets that are underweight.<\/div><\/div><\/span><\/p>\n For dogs and cats of any size,4<\/sup> RER (kcal\/day) = 70 <\/b>\u00d7 body weight (BW [kg])0.75<\/sup><\/b><\/span><\/p>\n In today\u2019s age of smartphones, simply changing the orientation of most phones enhances the standard calculator to a scientific one. However, this equation can be calculated on a standard calculator with a simple hack: multiply the body weight in kilograms (BW kg) by itself twice (BW kg \u00d7 BW kg \u00d7 BW kg), then press the square root key twice (\u221a, \u221a) and multiply the result by 70.10<\/sup><\/span><\/p>\n Just as with human foods, the calorie content of pet foods varies tremendously among diets. This can be helpful in explaining recommendations to owners. For example, 2 different spaghetti recipes can differ not only in their nutrient profiles but also in caloric density (sometimes drastically). One may include meat in the sauce, which will increase the protein content as well as the fat content, depending on the type of meat used. As a result, the same-size serving of each will have a different caloric density. The same drastic variance is found when comparing commercially prepared diets for pets and patients. Even minor adjustments to the formulation of a diet can have a significant impact on the diet\u2019s nutrient profile and caloric density.<\/span><\/p>\n When choosing a diet, several factors should play a role. First, the diet should be appropriate for the age of the animal. Puppies and kittens have a tremendously higher caloric requirement than adults and senior pets. The activity level and reproductive status of the animal must also be considered\u2014pregnant, lactating, and working animals have a higher DER than sedentary ones. If the pet has a medical condition that can be (at least partially) managed with diet manipulation, such as chronic kidney disease, diabetes, or uroliths, the diet should also cater to that particular need. <\/span><\/p>\n The formulation of the diet is another factor to consider. A diet in kibble form will have a different caloric density than the same diet in a canned formulation. It is common to also find variations in formulations such as flavor (seafood, poultry, beef) and texture (p\u00e2t\u00e9, stew, gravy). It is important to remember that the caloric density of even the most similar of diets is likely very different. For many pets, even small adjustments to caloric intake can cause a significant change in body condition.<\/span><\/p>\n When providing feeding instructions to an owner, it is crucial to be specific. Coach owners in the importance of using true measuring devices (such as a measuring cup or gram scale) instead of a mug from the kitchen or an unlabeled scoop from the pet store. Even though pet foods are required to include feeding instructions on their label, the method used to determine these recommendations can differ by company9<\/sup> and is not on the label. Therefore, despite an owner\u2019s strict adherence to the feeding instructions on a diet\u2019s packaging, a pet\u2019s body condition may not be ideal when evaluated at a veterinary visit. Without specific instruction and explanation to the owner when a diet recommendation is made, these types of weight management discrepancies can lead to distrust in the veterinary staff.<\/span><\/p>\n Be specific about the number and type of treats allowable in the feeding plan. Table scraps and additional treats unaccounted for in the feeding plan are not allowed while a weight management plan is in effect. The addition of extra snacks not only jeopardizes the outcome of the feeding plan, but also creates the potential for nutrient imbalance. This typically occurs when an intake of more than 10% of the pet\u2019s total daily calories is from sources that are not complete and balanced, such as treats and table foods.<\/span><\/p>\nEnergy Balance<\/h3>\n
Resting Energy Requirement Versus Daily Energy Requirement<\/h3>\n
![\"\"](\"https:\/\/todaysveterinarynurse.com\/wp-content\/uploads\/sites\/3\/2022\/05\/Olson_TVNSummer22_NutritionCalculations_Table1.png\")
<\/a><\/p>\n<\/a><\/p>\nBody and Muscle Condition Scoring<\/h3>\n
Putting It All Together<\/h2>\n
\nSophie is currently being fed Purina Pro Plan Adult Large Breed Chicken & Rice Dry Formula (407 kcal\/cup). She is given 1 scoop in the morning. The scoop is from the pet store and is not marked with any type of measurement. After appropriate measurement, the scoop is found to hold approximately 2\u00bd cups when full (level with the edge of the scoop). Her owner estimates that she gets 1 or 2 large Milk-Bones each afternoon (125 kcal each) but is not given table foods or other treats. As she is currently being fed, Sophie\u2019s caloric intake is approximately 1206 kcal\/day.<\/p>\n
\nTo create a dietary recommendation for Sophie, her resting energy requirement (RER) and daily energy requirement (DER) need to be calculated.<\/p>\n
\nRER = 70 \u00d7 body weight (kg)0.75<\/sup><\/p>\n
\nDER = RER \u00d7 appropriate factor<\/p>\n
\nPurina Pro Plan Adult Large Breed Chicken & Rice Dry Formula has 407 kcal\/cup.<\/p>\n\n
\n1911 kcal\/day \u00f7 407 kcal\/cup = 4.69 cups kibble\/day (approx. 4.75 cups kibble\/day) <\/strong><\/li>\n
\n1911 kcal\/day – 125 kcal\/day (Milk-Bone) = 1786 kcal\/day (kibble)
\n1786 kcal\/day \u00f7 407 kcal\/cup = 4.38 cups\/day (approximately 4.375 cups\/day)
\n1911 kcal\/day = 1 Milk-Bone + 4.375 cups kibble\/day<\/strong><\/li>\n<\/ol>\nGather an Accurate Diet History<\/h3>\n
Calculate Energy Requirements<\/h3>\n
\n<\/span>Pet Nutrition Alliance Calorie Calculator for Cats<\/strong> petnutritionalliance.org\/cat.php <\/a><\/span><\/p>\nMake a Diet Recommendation<\/h3>\n
Appropriate Measurement Is Key<\/h3>\n
Monitor and Adjust<\/h3>\n