Omega 3 fatty acids are widely used in both dogs and cats affected from chronic kidney disease (CKD). In dogs with proteinuric renal disease, clinical trials demonstrated the efficacy of Omega3 in reducing the protein loss and slowing the progression of renal disease and glomerular damage particularly if administered in association with antioxidants. In cats, no clinical trials evaluating the efficacy of Omega3 in slowing the progression of renal disease is available, although a retrospective study evaluating survival times of cats feeding different diets have showed a longer life-span in those cats eating the greater content of Omega3 fatty acids.
It should be underlined that, both in canines and felines, the efficacy of Omega3 in controlling the progression of renal disease has always been studied in patients feeding a renal diet. No data is available about Omega3 administered not in association to a renal diet. Omega3 useful in course of chronic kidney disease are EPA and DHA and the daily dose should be determined considering the amount of EPA and DHA administered with the diet, supplementing the feed ration with fish oil. Furthermore, Omega3 should be mainly represented from EPA and a fewer amount of DHA; it will be necessary to supplement the daily diet with oils at high concentration in EPA and low DHA.
On a side note, it has to be remembered vegetal oils contain Omega3 as ALA, which are converted to a minimal part in EPA and DHA in canines, while cats are not able to convert ALA at all thus resulting in a lack of efficacy in case of CKD.
Although it is not known the exact quantity of Omega3 to be administered to dogs and cats affected by CKD, several authors report a content of 1 gram of every 4.5 kg of weight to be administered daily in both species .