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A male has viable sperm by the time he is 6 months old but they must be at least 7 months old to have an AKC registerable litter.
Keep in mind that AKC Rules do not allow, except with special documentation, the registration of a litter out of a dam less than 8 months or more than 12 years of age at the time of mating, or by a sire less than 7 months or more than 12 years of age at the time of mating."
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