whoa...just woke up to find this...sorry I have not replied earlier as I have been abroad....well abroad for me...anyway...Hi Malibu, The behaviour you are describing is unusual though not abnormal...The behaviour is very similar to other 'primitive' behaviours such as turning several times before lying down and rolling in things that smell nasty in so much as it has little relevance to modern life for domesticated dogs. Or does it? To us it does, but these are certainly behaviours through which a dog can express itself. The apparently ritual and ineffective burying of uneaten food is likely to hark back to the days when the ancestors of the domestic dog hunted and scavenged. Remaining food would be buried for later use. The compulsive element of this behaviour in your own dog suggests some level of anxiety related to the behaviour. Often, as you have discovered, something as simple as a diet change can eliminate behaviours like this. Other approaches would include feeding in different locations, using different equipment (a plate instead of a bowl etc.) or completely changing the style of feeding (using activity balls or scatter feeding). As for the pros and cons of Science Diet, I am not a nutritionist so I cannot comment other than as a pet owner. I agree that it is overpriced, I know that vets get huge kickbacks for selling it and my last puppy would have rather starved than eat it.
Chris unfortunately the eating of poo is a very normal behaviour for dogs. Cat poo is high on the list of canine delicacies. As long as you allow your dog to have unsupervised access to cat poo, your dog will eat cat poo.
Seashell, that behaviour is fairly normal too although it should be checked with a vet. It can be genetic, learned or a sign that the dog is unwell.