Good Morning and welcome. I am Dr. Loretta, a licensed veterinarian and I am happy to answer your question.
It may be that Freddie did have a different upbringing causing him to want to chase other small animals but the treatment is the same.
1. Purchase a DAP Collar (Dog Appeasement Pheromone) at the pet store. This is a canine pheromone that acts as a calming agent and will decrease anxiety.
2. Purchase Rescue Remedy at the pet store. This is another anti anxiety herbal medication.
3. Carry a coke can with pennies and when Freddie is whining, shake the can loudly and say a strong NO!
4. If you have the time, take him back to a good obedience school again I know you have done this but this is key in stopping this bad behavior. This will help make you the "Alpha" dog and he will be more apt to listen to you.
5. Take Eddie for more walks...exercise will decrease this stress.
People also use the Ultrasonic Collars to control the barking and the need to chase. This is not cruel and will help because sometimes you may not present to stop this behavior.
Your vet has stronger anti anxiety medication that will help Freddie past this behavior if the collar or herbal remedies are not enough. This helps to hasten the process.
Does that make sense to you?
Please let me know if you have ANY other questions. My goal is to give you 100% satisfaction and if you are not yet satisfied, please Reply so I can clarify for you
Sincerely, Dr. Loretta