Dependent upon the type of hunting you are intending to do. If you are looking at a dog that is primarily for upland, now is fine, but if you are looking for one that it's primary use will be for waterfowl, I like to get them when the water is not too cold for them. I have seen many dogs that have trouble getting back into water if exposed to fridgid cold water as a young pup. No matter when I get a pup though, I always keep them strictly on obedience for at least 8 months, till they are rock solid on it. Most dogs are under trained in obedience and the Owners wonder why the dog breaks, whines, squirms, etc due to lack of obedience.
Breeding and Training Boykin Spaniels, a True American Gundog