First of all, Kudos to you for adopting an unwanted dog.
The Brittany is first and foremost a working dog. Although, they are one of the more popular hunting dogs because their friendly dispositions make for wonderful house pets as well. However, because of their keen intelligence and their need for exercise and to do a job, they are not always recommended for every family. You have to understand that this dog is going to take more work than your Golden ever did.
The walks morning and night are a good idea. So would be one of those tennis ball throwers. For as often as you are going to have to throw that tennis ball, it really saves the arm.
But the first thing you need to do is find an obedience class and quickly. You need to learn to channel this energy into positive behavior. And you need to do it fast before any bad habits are learned. Especially since she has been basically ignored for 5 months. She is at the perfect age to start obedience training. Believe me, this is a breed that absolutely should have obedience training, especially with a novice family.
This breed needs something to do. If you don't provide a stimulating environment, the puppy will make one up on her own. And chances are, you will not like her idea of a stimulating environment. There are many fun things you can do with your Brittany, ie: hunting. If you are not going to hunt, another suggestion would be that once you have basic obedience down, is to do agility with her. This is a very fun activity for both the dog and the handler, and would satisfy her energy needs and keep her mind busy. Remember, a bored smart dog is a destructive smart dog.
The next thing I would recommend to do quickly is to find some reputable Brittany breeders in your area. The best way to find them is to find your local AKC sanctioned breed club and contact them to find somebody in your area who is an expert in the breed. Explain to them what you have explained to us - that you rescued this puppy on the verge of it being put down. And that you need help in raising her properly. Most breeders are extremely busy with their own puppy people, however, most will bend over backwards to help a new family that has rescued one of their breed. Only from the experts can you learn the best way to raise this puppy to get the most benefit from the breed.
Here is the website for your national breed club:
http://clubs.akc.org/brit/
And here are a couple of the local breed secretaries. You should give them a call and ask them for pointers. They are the experts and they can give you much better info than any of us on the DIS can.
Hudson Valley
http://www.brittanyclubs.com/HVBC/
Nancy Morabito
PO Box 28
S. Bethlehem, NY 12161
pitabito@aol.com
Long Island
Dawn McCutchan
56 Applegate Dr.
Mastic, NY 11950
516-399-3756
Good Luck and Congratulations. She is a cutie!
FYI, the harder breeds are often some of the most rewarding breeds to own. The work you put into her, you will reap 1000 told the benefits! Start her off right and you will have one of the best family companions imaginable.