AAHA Nutritional Assessment Guidelines for Dogs and Cats

Animal-specific factors

Animal-specific factors include the age, physiological status and activity of the pet. Problems related to animal factors are referred to as nutrient-sensitive disorders (e.g., intolerances, allergies and organ-specific diseases). Diet choice for these animals should be restricted to those formulated to meet the disease-associated nutritional limitations of the specific animal.

Diet-specific factors

Diet-specific factors include the safety and appropriateness of the diet fed to the animal in question. Problems related to diet factors are referred to as diet-induced disorders (e.g., nutrient imbalances, spoilage, contamination, adulteration). Animals with these disorders may be treated by feeding a diet known to be appropriate for the animal.

Feeding management and environmental factors

Feeding factors include the frequency, timing, location and method of feeding, whereas environmental factors include space and quality of the pet’s surroundings. Problems related to feeding and environmental factors are referred to as feeding-related and environment-related disorders (e.g., over- or underfeeding, excessive use of treats, poor husbandry, competitive eating in dogs, and lack of appropriate environmental stimulation). These situations require effective communications to produce the appropriate behavioral changes in the client.

Screening evaluation

Nutritional screening is part of routine history taking and physical examination of every animal. Information collected should include assessment of each of the parameters of the circle of nutrition.

Certain life factors, by themselves, may not call for an extended evaluation if the animal is otherwise healthy. Low or high activity level, multiple pets in the home, gestation, lactation, or age <1 year or >7 years, all create a need for closer scrutiny. Although these factors by themselves may not trigger an extended evaluation, they should cause the veterinarian to scrutinize the pet’s situation more closely.

Specific risk factors known to influence nutritional status include those listed in Table 2⇓. When features are identified that raise one’s “index of suspicion” for a nutrition-related problem, an extended nutritional evaluation may be indicated.

The value of an extended nutritional evaluation increases as the number of risk factors and their severity increase. Moreover, sufficient concern about any one parameter may be enough to warrant extended evaluation.

If no concerns are raised by the screening evaluation, then the nutritional assessment is complete.

BCS and MCS

Use a consistent method and scale to measure body weight (BW), body condition score (BCS) and muscle condition score (MCS) to assess current status and changes over time. Although different scoring systems may have situation-specific merits, the panel recommends that practices choose, and all doctors and staff consistently use, one system and record the total points on which it is based (i.e., the denominator).

The BCS evaluates body fat [Figure 2⇓]. Various BCS systems are used to evaluate dogs and cats (e.g., scales of 5, 6, 7 or 9).^11,12,13

• Download figure
• Open in new tab
• Download powerpoint

• Download figure
• Open in new tab
• Download powerpoint

Figure 2—

Body Condition Scoring (BCS) Systems.

The goal for most pets is a BCS of 2.5–3 of 5, or 4–5 of 9. (This may appear too thin to some pet owners, so client education is important.) These BCS goals are based on a limited number of studies in dogs and cats^14,15,16,17 as well as those from other species. Disease risk associations with higher BCS in adult animals appear to increase above 3.5 of 5 (6 of 9). Similar risk associations for other life stages in client-owned pets have not been reported, but may occur at low BCS based on studies of laboratory-housed animals, and in humans.^16,18 Additional research on dogs and cats is needed to more fully evaluate the effects of body condition on disease prevention.

The MCS differs from the BCS in that it evaluates muscle mass [Figure 3⇓]. Evaluation of muscle mass includes visual examination and palpation over the temporal bones, scapulae, lumbar vertebrae and pelvic bones. Assessing muscle condition is important because muscle loss is greater in animals with most acute and chronic diseases (i.e., stressed starvation) compared to healthy animals deprived of food, when primarily fat is lost (i.e., simple starvation). Muscle loss adversely affects strength, immune function, and wound healing and is independently associated with mortality in humans.^19,20

• Download figure
• Open in new tab
• Download powerpoint

Figure 3—

Muscle Condition Scoring. A muscle condition scoring (MCS) system. Evaluation of muscle mass includes visual examination and palpation over the temporal bones, scapulae, ribs, lumbar vertebrae and pelvic bones. [Provided courtesy of Dr. Tony Buffington] This system currently is under development and validation.

A simple MCS scale is currently undergoing development and validation.²¹ The authors’ clinical experience suggests that early identification of subtle muscle loss, at the “mild muscle wasting” stage, is valuable for successful intervention.

Clinically, BCS and MCS are not directly related. An animal can be overweight but still have significant muscle loss. This can make an MCS of mild to moderate look relatively normal if not carefully evaluated. In these cases, although some of the areas of the body may appear relatively normal or even have excessive fat stores (especially over the ribs or in the abdominal region), muscle wasting is readily felt over bony prominences. Palpation is required for accurately assessing BCS and MCS, especially in animals with medium- to long-hair coats.

Extended evaluation

Extended nutritional evaluation of animal, diet, feeding and environmental factors is indicated for animals identified to be at risk for any nutrition-related problems from the screening evaluation [Table 2⇑]. Those items suggest that nutrition may play an important role in development of or management of the animal’s underlying disease, or life stage. First, review and summarize the history, medical record and information obtained during the screening evaluation. Second, obtain additional data as appropriate, as described below. A more detailed list of potentially relevant historical factors may be found in various references.

Animal factors

1. Evaluate the animal’s condition with respect to the current food intake. Estimate current energy needs. For inpatients, RER may be estimated using any of a variety of published formulas. For outpatients, either label recommendations or a formula may be used as a starting point. These are just population-based starting points for energy requirements, which can vary by 50% in either direction for cats, and by 30% in either direction for dogs (particularly with the MER).³⁶ These levels are further influenced by life stage, activity and environment variables.

2. Create a monitoring plan. Teach the client to monitor BW, BCS and/or MCS as appropriate. Adjust intake as needed to match changing needs over time.

3. Adjust or include dietary supplements if necessary, recommending specific types and amounts.

4. A diet change is sometimes necessary. Preferences for and recommendations about diet transition methods vary, with no clear evidence showing any one method is superior. Clinicians should use and recommend techniques based on their individual assessment of client and animal. Some animals tolerate an abrupt change in diet with little problem, although some appear to have fewer GI issues when food is gradually changed over a 7- to 10-day period.

Diet factors

1. Determine if current amount and type of food are appropriate, based on life stage, lifestyle/activity, disease, body condition, concurrent medications and/or medical procedures.

2. If diet factors are determined to be inadequate, prepare a plan for food and treats that provides appropriate calories and nutrient intake for the animal.

3. Consider other food sources in total intake recommendations if necessary.

4. Recommend a specific feeding plan that incorporates pet food, treats, table food, feeding method, frequency and location.

Feeding management and environmental factors

1. Determine any changes in feeding management and any necessary environmental changes.^37,38

   1. Whereas some dogs and cats can maintain good body condition when fed free choice, others require meal feeding of appropriate amounts to maintain good body condition.

   2. Confirm the use of an appropriate food-measuring device (e.g., an 8-oz measuring cup), and provide food in measured amounts (whether feeding free choice or meals).

   3. Management changes may include provision of feeding toys, and reducing conflict and competition for food.

   4. Environmental enrichment may include increased opportunities for activity (play, exercise), as well as efforts to decrease perception of threat from other animals (as well as humans) and reducing the frequency of unpredictable change in the animal’s environment.

2. Create a plan for hospitalized animals.

   1. Create a monitoring plan and a feeding plan as discussed under “Animal Factors” and “Diet Factors.”

   2. Offer usual and favorite (“comfort”) foods if at all possible to promote food intake. Avoid introduction of novel diets intended for long-term feeding to avoid the risk of inducing an aversion to the diet. A food aversion is avoidance of a food that the animal associates with an aversive experience.

   3. The optimal route required to achieve nutrient requirements should be reassessed daily, and may include:

      1. Voluntary oral feeding.

      2. Coax feeding — small changes, such as warming the food, taking the animal to a quiet area for feeding, having the owner feed the animal or stroking the animal while eating, can enhance food intake.

      3. Syringe feeding (be careful in animals with any nausea or who are stressed, as this can induce food aversions).

   4. Other nutritional support techniques will be required for animals that have not eaten sufficient amounts by the aforementioned routes for 3–5 days (this includes the time of reduced appetite at home before hospitalization), and are not expected to resume reasonable amounts of food intake prior to further compromise of their nutritional status.^39,40

      1. Use a feeding tube with animals that are not eating adequate amounts voluntarily. Use parenteral nutrition with animals that have gastrointestinal dysfunction or in animals whereby enteral feeding has increased risk of aspiration.

      2. Evaluate closely and watch for complications associated with the route of nutrition used, particularly with recumbent or neurologically impaired animals.

3. Create a plan for non-hospitalized animals.

   1. Create a monitoring plan and a feeding plan as discussed under “Animal Factors” and “Diet Factors.”

   2. Clearly inform the client of the recommended feeding management factors to ensure success. The client is part of the decision process and implementation of the specific action plan.

   3. If obesity is present, provide a comprehensive plan to modify the environment (e.g., exercise, behavior modification and/or prescription weight control medication).

   4. Create specific schedule for:

      1. Follow up via telephone to elicit questions and verify compliance/adherence to recommended feeding management or environment changes.

      2. Repeat examination/assessment.

4. Consult with a specialist or refer anytime one feels unqualified to take action and monitor an animal [Table 3⇑].

Healthy animals

Adults in good body condition should be reassessed regularly. Decisions regarding specific frequency of visits are made appropriately on an individual basis, based on the age, species, breed, health and environment of the pet. Healthy pregnant, lactating, senior and growing animals require more frequent monitoring. Pet owners should monitor their pet at home, including:

• Food intake and appetite

• BCS and BW

• Gastrointestinal signs (e.g., feces consistency and volume; vomiting)

• Overall appearance and activity

Animals with disease conditions and/or recommended nutritional changes

Non-hospitalized animals for which extended nutritional evaluation was indicated may require more frequent monitoring of nutritional assessment parameters. Monitoring should include the items in Table 2⇑.

Frequent monitoring of BCS and MCS is important, as many diseases are associated with suboptimal scores. Also, animals with medical conditions are more likely to receive dietary supplements and to have medications administered with food, so specific attention to and review of these issues, with an update of the dietary plan, are important at each visit to ensure that the overall nutritional plan is optimized.

Hospitalized animals

Daily monitoring of hospitalized animals includes the items in Table 2⇑, also evaluating these additional items:

• Specific feeding orders, which should include diet, route, amount and frequency.

• Fluid balance. Assessment of clinical signs (e.g., BW changes, pulmonary crackles) or diagnostic tests (e.g., central venous pressure).

• Addressing optimal route of intake. The optimal route required to achieve nutrient requirements could change during hospitalization and should be reassessed daily (see above).

• Quantifying and documenting nutrient intake (via all routes).

Many hospitalized animals are discharged prior to complete resolution of their underlying disease. Document and communicate to the client the feeding method, caloric intake, diet, frequency and specific monitoring parameters, and the schedule for rechecks and re-assessment.

Discuss with the client any issues that may limit adherence to dietary recommendations (e.g., feeding schedule issues, complex instructions, financial restrictions) and address appropriately (e.g., offer over-the-counter options for appropriate diets if financial restrictions will prevent the owner from consistently feeding the prescribed diet). Create a specific schedule for follow-up via telephone to elicit questions and verify compliance/adherence.

Provide choices in diets that meet nutrient goals. Create a plan with the client about what to do if calorie/nutrient goals are not achieved.

When abnormal parameters have returned to normal or stabilized, the animal may continue on a therapeutic diet or be transitioned to a non-therapeutic diet. If a new diet is necessary, it may be introduced gradually, as previously described.