Had a rude awakening tonight, just found out that Belle and cats don't get along.  Up until now, she'd treated them with a kind of wary curiosity.  Whenever she saw one, her ears would go up and she'd gaze intently at it, but she never ever attempted to chase one until now.

I had just let her off the lead, when she took off like a bullet, which was unusual.  I thought at first she was headed for one of her doggy friends, about thirty yards away, but she ran right past and that's when I saw the cat.  Recall - up till now, pretty good - went right out the window, nothing existed for her but this cat. It clambered over a fence, maybe five feet high, and I breathed a sigh of relief till I saw Belle launch herself into the air.  She actually landed on top of the fence, scrabbling with her back feet to try and get over.  Luckily, gravity prevailed, she dropped back down again, and came trotting back over to me, obedient as ever.

At the age of 18 months, did a switch suddenly turn on in her greyhound mind?  She's always muzzled anyway, when we go out, but up till now it's been because she picks things up off the ground.  Now there's another reason for never forgetting that muzzle.

Is this normal behaviour, or do they usually show an interest in the chase earlier than this?  Is Belle a late starter, or what?