Page 776 - Small Animal Clinical Nutrition 5th Edition

804 Small Animal Clinical Nutrition

CASE 37-2
VetBooks.ir Weight Loss in a Cat

David J. Polzin, DVM, PhD, Dipl. ACVIM (Small Animal Internal Medicine)
College of Veterinary Medicine
University of Minnesota
St Paul, Minnesota, USA

Patient Assessment
A 13-year-old spayed female domestic shorthair cat was examined for weight loss of several months’ duration.The owners had also
noticed increased water intake and urine volume, decreased appetite and a few episodes of vomiting in the last month.The cat also
seemed weak. Characteristics of the feces were unknown because the family dog often consumed any fecal material deposited in
the litter box. The cat usually remained indoors but did spend some time outdoors during the summer.
Physical examination revealed a very thin cat, with a body weight of 2.4 kg and a body condition score of 1/5. According to the
medical record, the cat weighed 5 kg four years earlier. Moderate accumulation of dental calculus was noted. Abdominal palpation
revealed excess accumulation of gas in the intestines and a small left kidney; the right kidney could not be palpated.
Results of a complete blood count revealed anemia (i.e., decreased total erythrocyte count, hemoglobin and hematocrit).
Significant serum biochemistry profile findings included azotemia, hyperphosphatemia, low normal serum potassium concentra-
tion and metabolic acidosis (Table 1). Serum thyroxine (T ) concentration was normal. Urinalysis was normal except for a urine
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specific gravity of 1.009. The tentative diagnosis was stage 4 chronic kidney disease (CKD).
Assess the Food and Feeding Method
The cat was normally fed a mixture of two different commercial specialty brand dry foods; one was a “light” food and the other was
a food formulated for older cats (mature adult food).The combination of dry foods was offered free choice.The owners noted that
the cat was still eating but overall appetite had decreased.

Questions
1. What are the key nutritional factors to consider in cats with CKD?
2. Prepare a treatment and feeding plan for this cat.
3. What parameters should be monitored if this patient goes home with conservative management?

Answers and Discussion
1. Key nutritional factors to consider in cats with CKD include water, protein, phosphorus, sodium, chloride, potassium, omega-3
fatty acids and antioxidants. Adequate water intake is important to maintain hydration, blood volume and renal perfusion in a
patient with polyuria. Parenteral fluids are indicated if vomiting, diarrhea, dehydration, blood volume contraction and renal
hypoperfusion are clinically important. Avoiding excess dietary phosphorus and protein will help reduce clinical signs of uremia
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and may slow progression of kidney disease. Compared with feeding a maintenance food, feeding a therapeutic renal food has
been associated with prolonged survival time and decreased occurrence of uremic episodes in cats with CKD. Increased intake of
omega-3 fatty acids and antioxidants has beneficial effects in CKD. Avoiding excess dietary sodium and chloride may help con-
trol systemic hypertension, which is a common sequela to CKD in cats. Potassium is also an important nutrient because hypo-
kalemia is common in cats with CKD and may lead directly to clinical signs in some cats. Adequate energy intake in the form
of non-protein calories is important in this cat to promote weight gain and minimize further catabolism of lean body mass.
2. Parenteral fluid therapy is indicated to promote excretion of nitrogenous wastes and improve overall hydration status. Water
should be available free choice at all times. The food offered to this cat should avoid excessive phosphorus, protein, sodium and
chloride while providing adequate amounts of potassium and increased omega-3 fatty acids and antioxidants. A commercial vet-
erinary therapeutic food or homemade food designed for cats with CKD should meet these nutritional goals. Because of nausea
associated with uremia, the food should be offered in small, frequent meals.The daily energy requirement (DER) should be cal-
culated to promote weight gain (i.e., 1.2 x resting energy requirement [RER] for an ideal body weight of 4.5 kg) after a normal
appetite has returned. Enteral or parenteral nutritional support may be necessary if the cat is eating less than its calculated RER
per day. Adjunctive medical therapy including antiemetics and H -receptor antagonists for uremic gastropathy and erythropoi-
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etin for anemia is indicated to improve the overall well being of the patient.
3. Clinical and biochemical parameters should be monitored two to four weeks after implementing nutritional recommendations.
A good response to conservative management includes decreased vomiting, increased appetite and activity level, weight gain,
decreased serum urea nitrogen and phosphorus concentrations and increased plasma bicarbonate concentration (or total CO ).
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Plasma bicarbonate concentration should be maintained within the laboratory reference range. Alkalinization therapy should be