Prey Drive

I think it depends on the individual dog and his breed.  I've had lots of success training a lab and a malinois a call off a chase, but I wouldn't trust any of the basenjis I have to do that.  (One of those basenjis is 9 years old, has a masters title in agility and is ready to enter OB or Rally, but I still wouldn't expect to be able to call him off a chase.)

what breed is the dog? unless it's a herding dog it's practically impossible to train the dog to abandon a chase in mid-chase. You may be able to control the START of the chase, though. I've had some success with putting the behavior on cue-- put the dog on a long line, and sometimes you say "get it" and let the dog chase, and sometimes you say "on by", and on by you go (do at least ten times on-bys for every get-it). Takes months of work, but accompanied by lots of regular obedience training eventually you get a dog who will rarely launch after an animal unless commanded to do so (although even then suicidal squirrels who leap out right under their noses can induce a chase).  And if you lay down an excellent recall, even if your dog does chase after a squirrel, you can always call him back after he trees it.
You can train dogs to not chase certain types of animals-- "crittering" the hunting dog trainers call it. Usually done with an ecollar. I've done this, for safety reasons, for deer chasing with my dogs.  They know deer chasing is forbidden.

Any thing is possible.  The issue is how hard are you willing to work to get it.  It would take consistent and long term training, first with minimal distractions then with more distraction.  Then a repeat of the same type of training programs but in different locations. 

The issue is how hard are you willing to work to get it.

I was going to say something like that

I have a very drivey JRT that will come from a dog fight or a chase (I've called her off of a running rabbit, successfully, more than once). It's all in the consistency and practice, practice, practice.

Thanks for all the feedback! Funny you should mention JRT. [] He is some sort of spitz (American Eskimo, we think now) crossed with a Jack Russell, and he has an incredible stubborn streak. He performs things well once he has been taught them, but lord, do they take forever to teach!

Have you tried clicker training? Emma learns 100000X faster that way.

I'm virtually a stranger when it comes to clicker training; I've only heard little bits about it. Does that not require a dog who is good at paying attention? I have problems with Cyrus because he has such a short attention span. I don't know if that has anything to do with the fact that he is not neutered (the date of neutering was pushed to sometime this April).

Check these sites out:
[linkhttp://www.clickertraining.com]www.clickertraining.com[/link] (this one has a trainer search)
[linkhttp://www.clickertrainusa.com]www.clickertrainusa.com[/link]