full answer to this question. We can however, assume that dogs
would not eat their own stool, other dog’s stools and cat poop
unless there was a reason. Often the easy answer is that they enjoy
it! although this may be a strange concept for most people to
accept.
There have been many studies looking for nutritional
deficiencies associated with eating feces, but so far, there isn’t
any hard evidence to support specific nutrient deficiencies as the
cause for eating stools. There is, however, some evidence that this
behavior can be acquired when dogs are bored or stressed when home
alone or similar scenarios. Still, this doesn’t fully explain why
so many dogs show this behavior. It seems that we just have to
accept that it occurs and that usually it will not cause too much
harm. 
eating feces though. It is a sure fire way of acquiring diseases
such as parvo virus and intestinal worms. Cat poop is less likely
to lead to disease than dog’s stools but there is still some
risk.
So what can be done about this behavior? The easiest solution is
to make it impossible for your dog to get to other dog’s stools or
the cat litter tray. Walking your dog on a leash is a good start.
Put your cats litter tray inside a cardboard box or behind a baby
gate to prevent access. 
market, one is called “Forbid”. It seems to work only for some
dogs. Other commonly used tactics are to place a small amount of
meat tenderizer on the dog’s food to discourage stool eating.
Obviously, this will only work when you are feeding the dog whose
stools your dog is eating.
Some people advise adding something like Tabasco sauce to the
feces to discourage eating the stool. Hiding the hot sauce by
splitting a stool in half and adding some of the sauce inside the
stool, then putting it back together seems to work better in
discouraging the behavior. But for the dirty work to do this it may
be better to just invest in a muzzle or pick up the feces before
your dog gets to it.