Originally Posted by cassiek
I wonder what the mechanism is that a high protein diet could trigger such issues? Hmmmm...
One theory is that a diet very high in protein can interfere with the absorption of certain essential amino acids such as tryptophan (one of several not supplied by the body but by food sources). Levels of serotonin, derived from tryptophan, are therefore reduced. Serotonin is one of the brain's neurotransmitters that affect mood, appetite, sensory perception, etc.
"Low serotonin levels produce insomnia and depression, aggressive behavior, increased sensitivity to pain, and is associated with obsessive-compulsive eating disorders."
I did a quick google search and there's more discussion about a high level protein diet's effects on human behavior than there is on dogs. There's also research on the effects of high protein on the behavior of rats:
"These data suggest that consumption of a long-term, high-protein diet leads to hyperactivity, hyper-responsiveness, and anxiolysis in rats."
When I have some free time, I'll look into this more and post links to research/articles here.
It's been almost 1 week since we stopped feeding kibble altogether and we've noticed a huge difference in the activity levels of our guys, especially Penny. In addition, she's less hypersensitive, less reactive, and more social. I can't help but think that diet, specifically protein levels, plays a large role in her behavior swings.