'buttferflywings' makes some good points, but the last line
of the post really tells it all:

> Animals just need to be cared for.
> Given baths,clean food, clean water, 
all easy enough!

> and kept in a hygenic environment. 
This one is impossible though.  If you have a 
dog and you take it to the park, your dog
*will* find a way to get dirty, and it 
will encounter viruses.

The best way to keep your dog alive is
to get him/her vaccinated.