http://www.springerlink.com/content/wm603v3105n17k65/The above link is to an abstract of a study involving dogs and aggression. More research is needed, but very interesting nonetheless.
"Altogether, our results suggest that low omega-3 fatty acids may adversely impact behaviour in dogs, resulting in greater propensity to aggression. However, given the cross-sectional design of our study, we cannot claim any causal relationship between the presence of alterations in fatty acid status and canine aggressiveness. Whether omega-3 fatty acids supplementation may be useful to reduce aggressive behaviour in the dog deserves further investigation."
