In humans and animals, brain and retinal functions are dependent on the n-3 polyunsaturated fatty acid docosahexaenoic acid (DHA 22:6 n-3)5 during in utero development and postnatal life.

The period of maximum brain growth in humans begins in the third trimester of gestation, peaks at birth, and continues throughout the first 18 months of neonatal life.

It is during this crucial period that accretion of arachidonic acid (AA) and DHA in brain and retinal phospholipids proceeds at a rate 10 times faster than incorporation via chain elongation and desaturation of their respective precursors, linoleic acid (LA) and α-linolenic acid (ALA).

Retinal DHA is highly conserved and has an important role in neurologic function.
Canine retina is capable of synthesizing DHA from its 22-carbon precursor, docosapentaenoic acid (22:5 n-3, DPA). Bauer et al. reported DPA accumulation, but not DHA, in canine plasma phospholipids when the precursor ALA is fed. It therefore is likely that plasma DPA provides substrate for DHA synthesis in canine retina and other nervous tissues.

Thus, a dietary source of preformed DHA or one of its precursors may be necessary during gestation and suckling for normal neural development in dogs.

The electroretinogram (ERG) is a sensitive measure of retinal function in humans and animals (10,11). It quantifies photoreceptor responses and their subsequent postsynaptic signals to a series of varying-intensity flash stimuli and includes the responses of many retinal cell types. Major ERG components have been studied in dogs (12), which appear to be a suitable model for studies of human retinal physiology and pathology (13).

The present study investigated ERGs of puppies born to mothers fed diets varying in marine (n-3) long-chain polyunsaturated fatty acid (LCPUFA) content. Maternal plasma phospholipid (PL) fatty acids were also evaluated during gestation and lactation to evaluate diet effects on fatty acid metabolism during canine reproduction.

PMID: 16772476

See following website for full manuscript