NUTRITION
Nutrition
Dr Liesel van der Merwe, BVSc MMedVet(Med)Small Animals
University Of Pretoria , Department of Companion animal
Clinical Studies
Email: [email protected]
The Utility of Omega-3 and Omega-6 Fatty Acids in Canine Diets
Fat has numerous functions within the body. In the diet,
it provides the most concentrated form of energy of all
nutrients, providing double the gross energy of protein or
carbohydrate. Dietary fat also acts as a carrier that allows
the absorption of fat-soluble vitamins and provides
essential fatty acids (EFAs) that the body has a
physiological requirement for. It’s found in evening primrose, safflower, hemp and
borage oils.
• AA (arachidonic acid) – AA is found only in animal fats,
as well as some fish. Although the dog is able to
synthesize adequate amounts of AA during all life stages,
its is a conditionally essential nutrient for cats during
pregnancy and neonatal development.
There are three distinct families of unsaturated fatty acids:
Omega-3, Omega-6, and Omega-9. All of them are pol-
yunsaturated (PUFAs), having 2 or more double bonds
and are named for where in the chain the double bond is
made. The different length, number, and type of double
bonds dictate different structure and function in the body.
The Omega families cannot metabolically interconvert. Sources of Omega 3 PUFAs
• α-LA (α-linoleic acid) is considered required as a precursor
to the long –chain PUFAs, EPA and DHA, although ex-
act requirement levels are not well defined for dogs and
cats. It is found in green vegetables, grasses, fruits and
plankton, and in flaxseed oil.
• EPA (eicosapentaenoic acid) and DHA (docosapentaenoic
acid) are long-chain Omega-3 fatty acids that are found in
the oils of cold water fish, algae, and to a lesser degree, in
the fat of grass-fed land animals.
The type of fatty acids in the diet can have significant effects
on general health and condition, on immune function and
production of inflammatory mediators. Numerous studies
and clinical investigations into fatty acid nutrients have
concluded that long-chain Omega-3 fats, most notably
EPA and DHA, provide important health benefits in humans
and domestic animals, including dogs. However, most
commercial canine diets contain predominantly Omega-6
(LA, γ-LA, AA) fatty acids. Blood plasma levels of dogs fed
these diets usually contain a lower level of omega-3, which
can be increased by a dietary change or supplementation.
Sources of Omega 6 PUFAs
• LA (linoleic acid) is regarded as the most important Ome-
ga-6 fatty acid. Deficiencies can cause skin lesions and
retarded growth. LA is found in most vegetable oils such
as corn, soy, sunflower, as well as chicken and pork fat.
• GLA (γ-linoleic acid) – In most animals, including dogs,
gamma-linolenic acid (GLA) can be synthesized from LA.
PUFAs’ fulfill several main functions:
• EPA and DHA support normal cell membrane fluidity giving
structural integrity
• AA, GLA, EPA, DHA are precursors to the synthesis of
eicosanoids, immunoregulatory molecules.
• LA is responsible for maintaining the cutaneous water
permeability barrier
• Cholesterol metabolism and transport (Es kimo people
don’t have heart disease!)
• AA and DHA Normal retinal and neurological development
in neonates
AA is precursor of hormonelike group of compounds:
prostacyclins, prostaglandins, leukotrienes, and thromboxanes
that are involved in processes such as vasodilation,
vasoconstriction, muscle contraction, blood pressure
Issue 02 | APRIL 2017 | 33