The basic strategy for controlling chasing cats is to work on the COME Instruction to strengthen its pull to be greater than the tendency to chase the cat. If your dog is in full close pursuit, it is unlikely the Instruction will work. In this case, you will have to chase him down to interrupt the chase and save the cat. Therefore, in a situation where you know there is a possibility of close contact, your dog will have to remain on leash.

Walking dogs off leash is not recommended for both safety and behavioral reasons.  Consider off-leash exercise in a securely fenced area.  Dog parks are a good alternative for friendly dogs.

If you are visiting someone with a cat, use the "Close Tethering" technique for the dog. This allows you to take the dog anywhere, without a problem. (If you are not familiar with Close Tethering, look for this topic in the ABN Library.)

For dogs in your home, interrupt any sign of a chase with a vocal, "Ah-ah" or "Off" Instruction.  The pre-emptive approach is more successful than a reactive one.  If the dog responds to your interruption, use a clicker to immediately reinforce a correct response, followed by a very special food treat, saved just for this challenging lesson.

Try to give this dog personality lots of exercise. Between you and others walking your dog, plan on spending some real time and effort on the "Come" Instruction. Because of the intensity of the chase instinct, we will have to OVER compensate with work on this Instruction to increase reliability. The goal is for COME to be more compelling than beginning to chase a cat. (Once he is in full pursuit, it is time for you to chase!) Work with him off leash and gradually increase distances.

If you are walking and he "alerts" on a cat, immediately say, "Off" (stop looking or touching) then immediately say, "Come" and physically redirect him to come to you. Even "alerting" on a cat needs to trigger a reflex to turn toward you (or the walker) and look for a treat. This needs to be reliable, so try to walk with treats in areas you will see cats. If you don't have a treat, substitute lavish praise for coming to you away from a cat. Try to avoid any possibility he or she will see a cat while off leash.

Ultimately, you know your own dog better than anyone else, and know how far to trust his behavior. Most importantly, remember you are responsible for protecting all cats that your dog might meet.