Everyone knows that cats and dogs, America's most popular pets, are very, very different. Dogs are loyal, truly man's best friend. Cats, on the other hand are diffident at best. Now, from veterinary research comes confirmation that cats are psychologically manipulative:

They don't talk, but when cats are upset about a change in their environment they let you know by acting sick - refusing to eat and vomiting excessively, even if they're healthy, a new study finds.

"For veterinary clinicians, when you have a cat that's not eating, is not using the litter box or has stuff coming up out of its mouth, the quality of the environment is another cause that needs to be addressed in coming up with a diagnosis," said study researcher Tony Buffington, a professor of veterinary clinical sciences at Ohio State University.

When cats in the study experienced "unusual external events," such as a change in the caretaker or feeding schedule, the healthy ones were just as likely as the chronically ill ones to exhibit sickness behaviors.

Excerpts from a Dog's diary:

8:00 am - OH BOY! DOG FOOD! MY FAVORITE!

9:30 am - OH BOY! A CAR RIDE! MY FAVORITE!

9:40 am - OH BOY! A WALK! MY FAVORITE!

10:30 am - OH BOY! A CAR RIDE! MY FAVORITE!

11:30 am - OH BOY! DOG FOOD! MY FAVORITE!

12:00 noon - OH BOY! THE KIDS! MY FAVORITE!

1:00 PM - OH BOY! THE YARD! MY FAVORITE!

1:30 PM - ooooooo. bath. bummer.

4:00 PM - OH BOY! THE KIDS! MY FAVORITE!

5:00 PM - OH BOY! DOG FOOD! MY FAVORITE!

5:30 PM - OH BOY! MOM! MY FAVORITE!

Excerpts from a Cat's diary

DAY 752 - My captors continue to taunt me with bizarre
little dangling objects. They dine lavishly on fresh
meat, while I am forced to eat dry cereal. The only
thing that keeps me going is the hope of escape, and
the mild satisfaction I get from ruining the
occasional piece of furniture. Tomorrow I may eat
another house plant.

DAY 761 - Today my attempt to kill my captors by
weaving around their feet while they were walking
almost succeeded, must try this at the top of the
stairs. In an attempt to disgust and repulse these
vile oppressors, I once again induced myself to vomit
on their favorite chair...must try this on their bed.

DAY 765 - Decapitated a mouse and brought them the
headless body, in attempt to make them aware of what I
am capable of, and to try to strike fear into their
hearts. They only cooed and condescended about what a
good little cat I was...Hmmm. Not working according to
plan.

DAY 768 - I am finally aware of how sadistic they are.
For no good reason I was chosen for the water torture.
This time however it included a burning foamy chemical
called "shampoo." What sick minds could invent such a
liquid? My only consolation is the piece of thumb
still stuck between my teeth.

DAY 771 - There was some sort of gathering of their
accomplices. I was placed in solitary throughout the
event. However, I could hear the noise. More
importantly I overheard that my confinement was due to
MY power of "allergies." Must learn what this is and
how to use it to my advantage.

DAY 774 - I am convinced the other captives are
flunkies and maybe snitches. The dog is routinely
released and seems more than happy to return. He is
obviously a half-wit. The bird on the other hand has
got to be an informant, and speaks with them
regularly. I am certain he reports my every move. Due
to his current placement in the metal room his safety
is assured. But I can wait; it is only a matter of
time......