Page 771 - Small Animal Clinical Nutrition 5th Edition

Chronic Kidney Disease 799

during hospitalization for dogs and cats with uremic signs. owner is often required and a trial-and-error approach must be
Finally, a common approach that is used for “picky” eaters is
VetBooks.ir to offer samples of several different foods and then recommend used with different foods, food forms (dry vs. moist) and feed-
ing methods (Box 37-5).
If caloric intake is insufficient to maintain body weight, clin-
the food they will eat. This may be effective in some patients
but there is a major disadvantage of using this approach in ical recommendations often include a stepwise approach de-
patients with CKD. The “cafeteria” approach should not be signed to facilitate adequate food intake (Polzin et al, 2005;
used in patients with diseases that commonly have a learned Polzin, 2007). The first step is to ensure that metabolic and
food aversion or that have limited commercial veterinary ther- other medical causes of decreased appetite have been corrected
apeutic food options (Delaney, 2006). Offering samples of all including dehydration, gastrointestinal hemorrhage, metabolic
the commercially available veterinary therapeutic renal foods to acidosis, hypokalemia, anemia, urinary tract infection, dental
a CKD patient that is not eating well or has uremic signs disease and drug-associated anorexia. Recombinant human
i
should be avoided to minimize the likelihood of a learned food erythropoietin has been used successfully to improve clinical
aversion to all the foods the patient may need to be fed long- well-being of dogs and cats with CKD; improved appetite may
term (Delaney, 2006). precede improvement in hematocrit values in some CKD
patients managed with erythropoietin (Cowgill et al, 1998).
Significantly improved appetite also has been noted in cats with
REASSESSMENT proteinuria (UPC ≥1), when managed with the ACE inhibitor
j
benazepril (King et al, 2006).When metabolic and other med-
Frequency of reassessment depends on the stage of CKD and ical causes of anorexia have been excluded or corrected, therapy
presence of concurrent conditions. Patients with azotemia for uremic gastroenteritis should be initiated with an H -
2
should be rechecked every two to three months and uremic antagonist such as ranitidine or famotidine. If inappetence still
patients should be rechecked as often as every two to four persists, appetite stimulants such as cyproheptadine or mirtaza-
k
weeks. Duration between evaluations may be longer in patients pine can be attempted; however, results are unpredictable,
with stable disease. Parameters included in the reassessment are intermittent and tend to be short-lived (Delaney, 2006).
listed in Table 37-13. Serial evaluation of appropriate laborato- Regardless of the effects of the above treatments on appetite, it
ry tests, including UPC ratios, is a good means of reassessment. is important to confirm that any apparent response to such
Because of daily variation in UPC ratios, minor changes in therapy sufficiently enhances food intake to meet nutritional
UPC ratio may or may not be clinically important. It is impor- goals.
tant to monitor trends on multiple UPC ratios over time rather If food intake remains inadequate to meet caloric needs for
than rely on individual measurements. Increasing UPC ratios more than three to five days with no trend toward improving,
over time can indicate worsening glomerular disease, whereas assisted feeding is indicated (Delaney, 2006). Long-term use of
serial declining UPC ratios are consistent with clinical im- percutaneous gastrostomy or esophagostomy tubes has been
provement. Decreases in urine protein concentrations, howev- successful for delivering food, extra water and medications to
er, may not always be associated with improved glomerular patients with CKD (Elliott et al, 2000a; Elliott, 2009) (Chapter
function. If accompanied by increases in serum creatinine con- 25). Anecdotal reports suggest that tube feeding can reverse the
centrations, declining UPC ratios may reflect progressive progressive weight loss associated with CKD and patients can
glomerular sclerosis and obsolescence. As glomeruli become have extended periods of improved quality of life (Polzin et al,
obsolescent, they no longer lose protein; however, these same 2005; Polzin, 2007).
glomeruli also lose their functional ability, potentially resulting
in azotemia.
After nutritional management has been implemented for SUMMARY
patients with CKD, it is very important to monitor for signs of
malnutrition (e.g., accurate body weights over time, body con- CKD is commonly diagnosed in dogs and cats and increases in
dition score, hematocrit, serum albumin) so that food offerings frequency with age. A variety of compensatory and adaptive
can be adjusted as needed. Unfortunately, it is common to see responses are likely involved in the pathogenesis and progres-
gradual weight loss over time and increasing the amount of sion of naturally occurring CKD. The goals of managing
food offered does not help if the patient has anorexia. A com- patients with CKD are to improve quality and quantity of life.
mon mistake is to insist that an owner feed only a veterinary Nutritional management plays a key role in both of these goals.
therapeutic renal food, even if caloric intake is inadequate. Although there are many available treatments, veterinary ther-
Although avoiding excess dietary protein and minerals is apeutic renal food is the only one that has been shown to pro-
important in patients with CKD, offering only such a food long survival time and improve quality of life for dogs and cats
should not be imposed to the detriment of overall nutrient with CKD.Therefore,nutritional intervention is a critical com-
intake. Changing to a different commercial food or homemade ponent of managing patients with CKD. When designing a
food may be a more beneficial solution for some patients. therapeutic regimen for dogs and cats with CKD, it is helpful
Appetite may be cyclical in patients with advanced CKD, both to consider key nutritional factors (water, protein, phosphorus,
in respect to overall appetite and food preferences. A dedicated omega-3 fatty acids, antioxidants, sodium, chloride and potas-