Indications for Nutritional Support

2. Indications for Nutritional Support

Some clinicians find it helpful to have metrics to use to determine when to intervene with nutritional support. Ideally, a specific and sensitive biomarker that is easily measured would exist as such an indicator. Unfortunately, despite attempts at identification, no one reliable indicator exists (De Bruijne, 1979; Fascetti et al., 1997). However, there are recommendations in the literature regarding patient criteria that can serve as indicators to when nutritional support should be instituted (Remillard et al., 2001).

First Criterion: the Length of Anorexia Prior to Presentation or Anticipated Duration of Anorexia

Canine patients that have been anorexic for three to five days are already in a state of starvation and, based on human respiratory quotients (RQs), are relying mainly on muscle and adipose tissue as energy substrates (Owen et al., 1979). There are no protein stores in the body, and, therefore, any catabolism results in the loss of functional proteins. A state of protein catabolism is contraindicated in any state of disease and minimizing or eliminating this catabolism is vital to the successful management of critically ill patients.

Not all patients have a clear starting point regarding anorexia. The client may not have recognized diminished food intake depending on the patient's home environment and the feeding strategy employed.
- Food intake for patients residing in a multi-dog household fed ad libitum is notoriously difficult to assess.
- Clients may, in hindsight, be reluctant to admit the length of anorexia or may exaggerate food intake.

In order to address this difficulty, the authors recommend that the practitioner make an effort to quantify the volume of food that the animal is consuming. Using this information, the approximate caloric intake of the patient can be calculated and compared to the animal's energy requirement

It is even more difficult to anticipate the length of expected anorexia. Disease progression is inherently unpredictable; however, many diseases do behave relatively predictably. In cases where there is a high likelihood that the patient will not eat voluntarily, plans should be made to provide nutritional support. Anticipating the potential need for nutritional intervention when patients undergo anesthesia for further diagnostics or treatment is strongly recommended. In this case, concurrently placing a feeding tube during the procedure is a critical management strategy. This approach drastically increases the odds that patients in need of nutritional support will receive it.

If anorexia lasts or is expected to last at least three to five days, it should elicit a nutritional response (enteral or parenteral feeding).

Other Criteria: Body Condition Score, Body Weight Change and Albumin Status

There are three parameters that need to be monitored in order to ensure that nutritional support is adequate.
- Patients with a body condition score of less than 3 on a 9-point scale (Laflamme et al., 1994) or 2 on a 5-point scale (Edney & Smith, 1986) should be considered to be in poor nutritional status, and nutritional support should be considered immediately (Figure 1).
- A body weight reduction of greater than five or ten percent that is not due to dehydration also signals the need for immediate nutritional support.
- Hypoalbuminemia due to decreased production is a clear indicator that intervention should occur.

Figure 1. 5 point body condition scoring system. A body condition score lower than 2 justifies the introduction of nutritional support. A weight loss in excess of 10%, starvation lasting more than 3 days and hypoalbuminemia are other criteria for evaluating the dog’s nutritional condition.