Anytime.

I had an epileptic beagle for 6 years. I knew it was time when he couldn't recognize me anymore, didn't pay attention to anything, was just pacing around and getting seizures all the time. Sigh... He was my best friend.

My current dog is a stray from Russia, was severely malnourished and afraid of everything when we got her in January 2007. Now she's happy and energetic - though a bit cautious when approaching new people. I love to watch her sleep on my bed and enjoy it 100% because I bet that back in Russia she never had the chance to do that. Most people think of dogs differently there. Some love them the way we do, and for some they are food.