.The potassium requirement for cats

.The potassium requirement for catsis proportional to the protein content of the food.Using purified foods, 0.3% potassium was required for growth in kittens fed a 33% protein food;however,0.5% potassium was required with a 68% protein food (Hills et al, 1982). Acidifying foods and chronic metabolic acidosis may contribute to hypokalemia (Figure 37-12) (Dow et al,1990). The recommended range for potassium for foods for dogs with CKD is 0.4 to 0.8% DM and for cats 0.7 to 1.2% DM. For cats with hypokalemia,oral supplementation with potassium gluconate should be considered if diet alone does not maintain serum potassium concentration above 4.0 mEq/l (Polzin, 2007). Oral administration is safest and is the preferred route unless a critical emergency exists or if oral administration is impossible or contraindicated. Oral potassium gluconate appears to be tolerated well;the initial recommended dose is 2 to 6 mEq potassium gluconate/cat/day, depending on the size of the cat and severity of clinical signs. The potassium gluconate dose should be adjusted based on clinical response and serial analyses of serum potassium concentration.During initial treatment, serum potassium concentration should be checked every two to four days. Later, serum potassium should be checked every two to four weeks.Additional studies are needed to determine whether routine potassium supplementation is indicated in all cats with CKD,regardless of serum potassium concentration (Polzin et al,2000).Omega-3 FattyAcids The specific dietary fatty acid content of a food can influence progression of CKD by affecting: 1) renal hemodynamics, 2) platelet aggregation, 3) lipid peroxidation, 4) systemic blood pressure, 5) proliferation of glomerular mesangial cells and 6) plasma lipid concentration. Appropriate levels of omega-3 (n3) fatty acids (e.g., eicosapentaenoic acid [EPA] and docosahexaenoic acid) in foods compete with arachidonic acid in several ways to alter eicosanoid production.These alterations are considered to be renoprotective (Brown et al,1998). Specific ingredients (e.g., menhaden fish oil) contain increased levels of omega-3 fatty acids; therefore, animals fed menhaden fish oil have decreased levels of 2-series eicosanoids, which are normally derived from arachidonic acid, and increased levels of 3-series eicosanoids, derived from omega-3 fatty acids.The 3-series eicosanoids are less potent at inducing vasoconstriction and platelet aggregation than the 2-series eicosanoids. Saturated fatty acids found in animal fat do not serve as precursors for eicosanoid production. In dogs with a remnant kidney model of CKD, dietary omega-3 fatty acid supplementation reduced proteinuria, prevented glomerular hypertension and decreased production of proinflammatory eicosanoids (Brown et al, 1998, 2000). Dietary fat composition altered the rate of CKD progression in dogs following 15/16 nephrectomy (Figure 37-13). A low-fat food (