This may be as old as the hills, but when a friend sent it around the other day, it was the first I had seen it:

Dog's diary:

7 a.m. Oh, boy! A walk! My favorite!
8 a.m. Oh, boy! Dog food! My favorite!
9 a.m. Oh, boy! Kids! My favorite!
10 a.m. Oh boy! The yard! My favorite!
Noon Oh, boy! A nap! My favorite!
2 p.m. Oh, boy! A car ride! My favorite!
3 p.m. Oh, boy! The kids! My favorite!
4 p.m. Oh, boy! Playing ball! My favorite!
6 p.m. Oh, boy! Welcome home Mom! My favorite!
7 p.m. Oh, boy! Welcome home Dad! My favorite!
8 p.m. Oh, boy! Dog food! My favorite!
9 p.m. Oh, boy! Tummy rubs on the couch! My favorite!
11 p.m. Oh, boy! Sleeping on my people's bed! My favorite!

Cat's diary:

Day 183 of my captivity... My captors continue to taunt me with bizarre
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 & the mild
satisfaction of clawing their furniture.

Tomorrow I will eat another house plant.

Today, my attempt's to kill them by weaving around their feet almost
succeeded... Tomorrow I 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 upchuck on their favorite chair. I must remember to do
this on their bed.

Decapitated a mouse and brought them the headless body in an attempt to
show them what I am capable of, and to strike fear in their hearts. They
only cooed and condescended about what a good little cat I was. Hmmm,
that did not work according to plan.

There was some sort of gathering of their accomplices. I was placed in
solitary during the event. However, I could hear the noise and smell the
food. More important, I overheard that my confinement was due to my
ability to produce "allergies". Must learn more about this.

I am convinced my other captives are flunkies and possibly spies. The
dog is routinely released and seems 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 on my every move.
Due to his placement in a metal room, he is safe from me for now. But I
can wait; it is only a matter of time...