Date Published: June 3, 2019
Publisher: Public Library of Science
Author(s): Irina Dahms, Eileen Bailey-Hall, Erin Sylvester, Audrey Parenteau, Shiguang Yu, Alexios Karagiannis, Franz Roos, Jon Wilson, Juan J Loor.
An Algal Oil Containing EPA and DHA (AOCED) at ~50% was developed as a sustainable source of omega-3 fatty acids. AOCED was incorporated into extruded dry foods for dogs at 0, 0.75%, 1.5% and 3.0% levels (equivalent to 0, 7.5, 15 and 30 g/kg diet) on dry matter basis at the expense of chicken fat and fed to healthy female Beagle dogs starting at mating and throughout gestation and lactation. The offspring were fed their maternal corresponding diets for 26 weeks after weaning. AOCED-enriched diets were well tolerated by dogs in both generations and did not affect their overall health, physiological parameters, food consumption, body weights and body weight gains. There were no changes in hematology, clinical chemistry, and coagulation parameters in both generations of dogs fed the AOCED diets when compared to those in the control group. Plasma levels of DHA and EPA increased significantly and generally dose-dependently in both generations. The study demonstrated the safety of AOCED in dogs during gestation, lactation, and growth periods at dietary levels up to 3.0wt%, equivalent to 30 g/kg diet. AOCED’s bioavailability as a source of DHA and EPA in dogs was demonstrated by the increased plasma concentrations of these nutritional lipids.
There is ongoing interest in the role of long-chain polyunsaturated n-3 fatty acids (n-3 LC-PUFA) docosahexaenoic acid (DHA, 22:6n-3) and eicosapentaenoic acid (EPA, 20:5n-3) in companion animal nutrition. Evidence has accumulated regarding DHA and EPA having a range of physiological roles that relate to optimal cell membrane structure and beneficial cell function and responses. DHA plays an essential role in the development of the nervous system , and along with EPA it is thought to modulate immune functions and reduce inflammatory responses .
This study was conducted at Citoxlab North America (Laval, Quebec, Canada) according to their standard operating procedures but not under good laboratory practice regulations. The study was designed with the reference to the following guidelines: CVM guidance for industry #56: protocol development guideline for clinical effectiveness and target animal safety trials; CVM guidance for industry #221: recommendations for preparation and submission of animal food additive petitions; VICH GL43 (CVM GFI #185): guidance for industry: target animal safety for veterinary pharmaceutical products; AAFCO dog food gestation/lactation and growth feeding protocols. The CVM is the Center of Veterinary Medicine, a division of the US Food and Drug Administration (FDA). Procedures involving the care and use of animals in the study were approved by the Institutional Animal Care and Use Committee prior to conduct. During the study, the care and use of animals were conducted in accordance with the principles outlined in the current guidelines published by the Canadian Council on Animal Care and the guide for the care and use of laboratory animals, an NRC publication and USDA regulations. Citoxlab North America facility is accredited by the Canadian Council on Animal Care and AAALAC.
Clinical signs observed in maternal females during the gestation and the lactation periods of the study were mainly related to variations in stool consistency, reported as soft/loose/liquid stool and reduced/absent fecal output. The signs were observed in all groups, including the control, and were not considered related to the consumption of the experimental diets. Fecal changes are common in laboratory-housed dogs, especially during pregnancy and parturition. There were no diet related effects on body temperatures, heart rates and respiratory rates during the gestation and the lactation periods. Individual variations in these parameters were considered incidental since similarly observed in the control animals, were transient and/or reflected the normal inter-animal variation in this species.
A comprehensive study in Beagle dogs was undertaken to provide evidence of safety and bioavailability of Algal Oil Containing EPA and DHA (AOCED) for reproduction, development and growth, at the dog early life stages as well at later in life. The administration of AOCED at dietary levels of 0.75%, 1.5% and 3.0%, which corresponded to doses of DHA and EPA of 0.44%, 0.83% and 1.69%, to female dogs, starting at mating and continued throughout gestation and lactation, was well tolerated by the dogs and did not affect their overall health and physiological parameters. Food consumption, body weights and body weight gains of AOCED-treated animals were comparable to those of the control group (Fig 1). There were no changes in hematology and clinical chemistry parameters in females fed AOCED diets compared to the control other than reduced cholesterol levels in the high-dose group (S2 and S3 Tables). This was expected due to known lipid-lowering effects of omega-3 fatty acids  and was observed in dogs administered omega-3 algal oils before .